Efficient exploration and SSR identification of autotetraploids from the seedlings of thirteen apomictic Citrus genotypes北大核心CSCD

【Objective】Citrus is a crucial part of Chinese fruit crops. There are abundant citrus germplasm resources in China, but many excellent local varieties are gradually eliminated by the market due to the problem of numerous seeds within the fruit. The fruits of triploid plants are generally seedless because of their sterile male and female gametes. Therefore, triploid production is a promising strategy to breed seedless cultivars in citrus. Triploids can be obtained by interploidy crossing between diploids and tetraploids. However, the tetraploid germplasm is rare, which limits the application of this strategy. Exploration of tetraploids is an important prerequisite for triploid production with the aim to improve the seedy local cultivars in our country. For the rootstock improvement, tetraploid plants are also valuable resources because of their higher metabolite content, and better resistance than their diploid parents. In this study, we planned to explore tetraploid plants from 13 local cultivars in our country by using the traits of spontaneous doubling of the nucellar cells in polyembryonic citrus varieties. The exploration of tetraploids from the above 13 local cultivars will not only provide excellent tetraploid parents for the production of triploid plants, but also lay the foundation for the basic research about the effect of genome duplication on some important trait change, such as dwarfing, extensive adaptivity and higher medicinal value in tetraploids.【Methods】After the mature fruits were harvested, the seeds were extracted and the seed coats were peeled off, and then they were placed in a thermostat to accelerate germination. When the seeds germinated, they were sown in pots and cultivated in a plant growth chamber. After the seedlings grew up with three or more leaves, putative polyploids were screened according to the morphological feature showing lower height, shorter taproots, less lateral roots, thicker and rounder leaves and declined oil gland density. The ploidy levels of these putative polyploids were further confirmed by flow cytometric analysis and the observation on root tip chromosome numbers. After determination of the ploidy level, some morphological traits, including plant height, root length and diameter, lateral root number, stem diameter, leaf thickness and shape index of the tetraploids and their corresponding diploid parents were measured at the same developmental stage. SSR analysis was used to identify the genetic origin of the explored tetraploids with at least three pairs of SSR primers selected for each cultivar.【Results】The polyembryonic degree of seeds from each cultivar was firstly determined and it showed that the seeds of all 13 cultivars were polyembryonic. Among them, Qu tangerine had the highest number of embryos with an average of 9.4 embryos per seed and Bingtang sweet orange had the lowest number of embryos with an average of 2.2 embryos per seed. Based on the morphological trait screening, we identified 2, 1, 3, 2, 7, 3, 1, 3, 1, 3, 17, 1 and 2 putative polyploids respectively from 343, 499, 892, 385, 519, 290, 457, 241, 119, 690, 828, 114 and 129 seedlings of Qianshanhong tangerine, Bayue tangerine, Qu tangerine, Zao tangerine, Bianping tangerine, Ougan tangerine, Shitougan, Bingtang sweet orange, Jinmi sweet orange, Moping Xiangcheng, Japanese Xiangcheng, Zhique and Youpi kumquat. After further confirmation of ploidy levels concerning above putative tetraploids, we obtained 45 tetraploids and one hexaploid plant from Qu tangerine, with an average occurrence rate of 0.85%, among which the rate of Japanese xiangcheng was the highest with 2.05% and the rate of Bayue tangerine was the lowest with 0.20%. The exploration time from seed germination to obtaining tetraploid seedlings varied among cultivars, with the longest time (42 days) used in Youpi kumquat and the shortest time (23 days) in Shitougan. The morphological traits of tetraploids and their corresponding diploid seedlings from nine cultivars of Qianshanhong tangerine, Qu tangerine, Zao tangerine, Bianping tangerine, Ougan tangerine, Bingtang sweet orange, Moping Xiangcheng, Japanese Xiangcheng and Youpi kumquat were measured. For plant height, tap root length, lateral root numbers and leaf thickness, the tetraploid seedlings of seven cultivars showed significant differences with their diploid parents. For taproot and stem diameter, only the tetraploid seedlings explored from Bingtang sweet orange and Japanese Xiangcheng had significant difference with their diploid parents. For leaf shape index, the tetraploid seedings from Bianping tangerine and Moping Xiangcheng exhibited significant differences with their diploid seedlings. In conclusion, most tetraploid seedlings of all nine cultivars showed lower plant height, shorter and thicker taproot, less lateral root number, thicker and rounder leaves than those of their diploid parents. These results provide supports for the screening of putative tetraploids based on morphological trait observation. For analyzing the genetic origin of the tetraploids obtained in this study, at least three SSR markers were used in each genotype. The results showed that the bands of all 45 tetraploids were identical with those of their corresponding diploids, indicating that all the 45 tetraploids might originate from the spontaneous chromosome doubling of nucellar cells of their corresponding diploids. In addition, the bands of the hexaploid from Qu tangerine were also identical with their diploid parent. We speculated that it might derive from chromosome doubling of a triploid zygotic cell, which formed by selfing of a FDR-type 2n gamete with a normal n gamete, and both gametes were produced by Qu tangerine.【Conclusion】This study verified that morphological screening combined with flow cytometry ploidy determination and SSR analysis is an efficient approach to exploring polyploid seedlings from apomictic citrus. Using this method, 45 autotetraploid and one hexaploid plants were obtained from 13 apomictic citrus genotypes. These newly discovered tetraploids are potentially valuable for not only genetic improvement of some elite local citrus cultivars with seeds produced by triploids using interploidy hybridization, but also selection of the promising rootstocks with dwarf, multi-resistance and broad adaptability characteristics to improve the ability to resist various abiotic and biotic stresses. © 2023 Journal of Fruit Science. All rights reserved.     

Breeding of a new grape rootstock cultivar‘Zhenghan No. 1’北大核心CSCD

‘Zhenghan No.1’was newly selected from hybrids of the cross between‘Hean 580’(female parent) and Shan putao (male parent) in 2008,432 hybrid seeds were harvested in autumn. In March 2009,156 hybrid seedlings were obtained by sowing hybrid seeds through sand accumulation treatment. Through selection and elimination,120 hybrid seedlings were preserved until 2011. In 2012,46- 8- 4 showed the characteristics of high cold resistance and salt-alkali resistance,and was designated as a superior cold-resistant rootstock line. In 2013,regional test sites were established in Weishi county in Kaifeng,Changyuan county in Xinxiang,Mengzhou county in Jiaozuo and Yanqing county in Beijing,and main varieties such as Sunshine Rose,Xiahei Seedless and Hutai No.8 were grafted. Regional test showed good grafting compatibility. The cultivar is high resistant to salinity tolerance,wide adaptability and high yield. It has good grafting affinity with common varieties in production.‘Zhenghan No. 1’ has strong growth potential,strong branch growth,few bad branches,good maturity of branches,and can yield 10 250 meters per mu. The relative conductivity and recovery growth of branches were measured after freezing at different temperatures. The semi- lethal temperature of‘Zhenghan No. 1’ was -30.78 ℃ ,‘Beida’was -28.88 ℃ ,‘Zhenghan No. 1’had higher cold resistance than‘Beida’,and the germination rate of‘Zhenghan 1’was also higher than‘Beida’. In spring,18 rootstocks of one-year- old‘Kangzhen No. 3’‘Kangzhen No. 1’‘HuajiaNo.8’‘DogRidge’‘Saltreek’‘Cloire’‘Beida’ ‘SO4‘’3309C‘’1103‘’5BB‘’SandyGrape‘’5C‘’775P‘’110R‘’420A‘’Zhenghan No. 2‘’Zhenghan No. 1’were cut into branches. Cuttings with 3-5 buds were cultured in laboratory. After the cuttings had grown a small number of roots,they were cultured with 1/10 Hoagland nutrient solution until the branches had grown a large number of roots. Treated with different concentrations of Nacl and saturated lime water. The results showed that‘Zhenghan No. 1’could tolerate 0.3% NaCl + 18% saturated lime water under hydroponic conditions,while Beida could only tolerate 0.2% NaCl + 15% saturated lime water. Compared with the commonly used cold-resistant rootstock‘Beida’,there was no obvious effect on the economic characters of the scion varieties such as‘Summer Black seedless’‘Hutai No.8’and‘Sunshine rose’. The survival rate of‘Zhenghan No. 1’grafted with‘Summer Black Seedless’and‘Hutai No. 8’was 90.0% and 86.6%,respectively; the yield of‘Sunshine Rose’grafted with‘Zhenghan No. 1’ could reach 646 kg in the second year and 2 132 kg in the third year. It can be seen that ‘Zhenghan No. 1’ had good affinity with the main varieties ‘Summer Black seedless’‘Hutai No. 8’and‘Sunshine Rose’. It began to germinate in early April,blossom in early May,branch began to aging in early July,leaves began to fall in early November,and the whole year’s growth period was about 216 days in Zhengzhou. ‘Zhenghan No. 1’had no leaf and branch diseases throughout the year,and no chemical control was needed. ‘Zhenghan No. 1’showed good plantability in different producing areas. It could grow normally in the areas such as Changyuan with low temperature in winter and Boai with cloyed ground. © 2019 Journal of Fruit Science     

Breeding of a new pear cultivar‘Xinli No.11’北大核心CSCD

‘Xinli No.11’is a new pear cultivar,which was bred by crossing‘Kuerlexiangli pear’as the female parent and‘Yali’as the male parent. Five single plant was initially selected in 1989 for theirs strong adaptability,good quality and different maturity charateristics,and then a single plant number‘75-4-1’was finally selected for its better comprehensive quality,early fruiting,high yield,strong cold resistance and stable agronomic traits charateristics,After regional adaptability testing at three sites (including Korla area,Tarim area and Yanqi area) over five years from 2014 to 2018,it was finally selected in 2018. We applied for the registration as a new cultivar in April 2018 and got identification certificate from Trees Variety Approval Committee of Xinjiang Uygur Autonomous Region in November 2019 and named‘Xinli No.11’. The canopy was conical under natural conditions,the young trees growth potential was flourishing. Leaves were ovoid and eiiipse with average 11.30 cm length and 9.08 cm width,petiole was 3.95 cm in length. Leaf color was dark green. Flowers were pale pink,the relative position of petals was separated. The petal shape was oval,pollen was abundant.It was mainly on the short branch in the fields with ratio of 64%. The average setting rate of single flower was 35.4% and the setting rate of single inflorescene was 86.2% under the condition of natural pollination. The fruit was gourd shape and regular,shed calyx. The average single fruit weights was 181.2 g. The ground col- or of fruit skin was green yellow. The fruit skin was smooth and shining,the peel was thin,the fruit dot was middle-small and was not obvious. The fruit flesh was creamy white,fine and crisp. It was juicy,sour-sweet flavor and tasted delicious along with aromas. The fruit quality was excellent. The content of soluble solid,soluble sugar,titratable acid and vitamin C was 13.42% ,10.41% ,0.108% and 41.9 mg · kg- 1 fresh,respectively. The sarcocarp hardness was 4.66 kg · cm- 2. The vigor of growth of‘Xinli No.11’was middle,germinating capability was high,branch development capability was middle. The fruit development period was about 140 to 150 days,the growth period per year was 210 days,and the fruit was ripening in early or middle of September in Korla,China. It can be stored in cold storage conditions for 5 to 6 months. It has the characters of early fruiting and high yield,the production of 3-4 year old tree was 2-3 times compared to‘Kuerlexiangli pear’. It began flowering after 2 years of planting and the average yield of individual plant was 9.7 kg at 4 years after planting,and it had better adaptability and strong cold resistance (can survive minus 28 ℃ low temperature). The orchard should with mild saline-alkaline and well drained soil. The suitable planting space in the rows and plants are (4-5) m×(3-4) m and 4 m×1.5 m,respectively. The suitable tree shape was evacuation and thin-long spindle. ‘Xinli No.11’has high rate of fruit setting under natural conditions,fruit thinning should be carried out within three weeks after fallen petal with a standard of leaving fruit with good shape and bright color without any diseases and pests and mechanical injuries. The fertilizer should be provided properly according to the period of growth and development and the tree age,and the water should be provided properly according to the soil moisture,both drip irrigation and flood irrigation are available. Grapholitha molesta,Cydia pomonella and Valsa canker should be regard as the most important pests and diseases and controled by scientific using physical and chemical technology according to their occurrence rule. © 2019 Journal of Fruit Science     

Genetic Analysis of Fruit Body Color in a Hybrid Strain of Flammulina velutipes

A series of hybrid Flammulina velutipes dikaryons were obtained by crossing yellow and white monokaryons.The color of fruit bodies generated from these dikaryons,and the ratio between dark-colored stipe regions and the entire stipe of individual fruit bodies,were determined.Our data suggest that the expression of fruit body color in the hybrid dikaryons was under the control of factors present in both the white and yellow parent monokaryons,and that multiple alleles exist in both white and yellow color-controlling factors.     

Effects of Fruit Thinning Severity on Yield and Quality in ‘Sensation’ Mango （Mangifera indica）

Four different fruit thinning severities were tested.The thinning treatments were carried out in October before the occurrence of physiological fruit drop.Different parameters were measured(both qualitative and quantitative) and the results compared among treatments as well as to that of the control.The results showed that wher fruit on ‘Sensation’ mango pani-cles were thinned to two fruit per panicle,a significant difference was obtained for most of the quantitative parameters.The fruits of the treatment where one fruit per panicle was retained and 50% panicles removed,produced the best results for most of the qualitative parameters.     

A new pest in vineyard under grass management model: study on the biological characteristics and control of Smaragdina nigrifrons北大核心CSCD

【Objective】For many years, our team have been working on organic cultivation management and pest control of wine grapes. Ground cover management model has been a new green management model currently implemented in the northern orchards. However, under the grass-covering system, new or secondary pests and diseases may increase in the orchards if the pasture type and planting and management models are not carefully chosen. These pests and diseases might become a new problem in fruit production. For example, a serious insect pest of wine grapes, Smaragdina nigrifrons (Hope) (Coleoptera: Eumolpidae) was found in the vineyard in Changli, China for the first time. This pest is highly harmful and occurs continuously in grass-covered orchards. In order to understand the occurrence and damage of the pest, the authors conducted field and lab investigations for three consecutive years. Its morphological characteristics were described, and its living habits, damage, and occurring pattern were observed, and the control methods were suggested.【Methods】Systematic field investigation was combined with indoor feeding and observation. Morphological characteristics of the beetles were observed under Primo Star microscope, and their taxonomic status was determined. The population dynamics and occurrence pattern were monitored by yellow cards trapping technique. 【Results】 The results showed that the adult of S. nigrifrons was long ovate. Female adults were 4.5 to 5.9 mm in length and 2.2 to 3.0 mm in width; males were 4.0 to 5.6 mm in length and 1.9 to 2.6 mm in width. Their head was black, the top was highly convex, and the leading edge had a wavy fold. There was no obvious boundary between the lip base and the forehead, which was slightly raised with numerous deep points. The tentacles were short and thin. The basal 4 knots of the tentacle were yellowish brown, the other sections were brown or black, and the sections after the 5th section were jagged. The chest was red brown or yellow brown. The scutellum and the elytra were yellow brown or red brown, and the elytra had wide black transverse band. Male's abdomen penultimate web was raised and female’s was sag. The adults of S. nigrifrons do damage on the tender new leaves. They had pseudo- lethality, coming out during the day and hiding at night. Generally it damaged tender leaves on the top of the canopy, with irregular notches in the injured leaves. The damage rate of local wine grape reached 100%. The adults usually appeared in July and August and might have one generation a year. They were active during 8:00 to 11:00 and 15:00 to 18:00. They had no phototaxis but had feigned death. In addition to harming the top leaves of wine grape trees, they also harmed the inter-row weeds, and the damage in the grass growing area was significantly more serious than in the weeding area. 【Conclusion】It is speculated that the occurrence and harm of S. nigrifrons in the wine grape vine of Changli Langes Winery is closely related to the implementation of the new orchard management mode with grass cover, indicating that it has potential risk. Therefore, it is extremely important to carry out a risk assessment analysis of S. nigrifrons. The occurrence and damage of S. nigrifrons in other fruit orchards in the north, especially in slopes, semi-mountainous areas and mountainous areas, needs further investigation. © 2019 Journal of Fruit Science     

早熟桃新品种‘锦玉’

 ‘Jinyu’is a early-ripening peach cultivar derived from the cross of‘Zhaohui’בOkayama Wase’. Its average fruit weight is 167 g,and the biggest one is 210 g. The fruit is oblong with red blush. The flesh is white,melting,sweet and semi-freestone. The soluble solids content is 13.2%. The average fruit development period is 72 days.     

A new yellow-fleshed kiwifruit cultivar Jinshi 4北大核心CSCD

Jinshi 4 is a new yellow-fleshed kiwifruit cultivar selected from crossbreeding. The seedling was derived from a cross between Jinshi 1 and SF0813m in 2009 at Shifang Kiwifruit Base of Sichuan Province. The vine vigor is strong. The new canes have short hairs of medium length. The annual canes are thick and the epidermis is medium coarse and dry. The canes have white short spindle lenticels. The volume of bud socket and bud pore of annual cane is large. There is strong anthocyanin coloring set on the front of the petiole of the young leaf. The tip of the young leaf was tail-shaped and open at the base. The shape of the adult leaf is heart-shaped, the leaf edge is sawtooth-wavy, there is no or very thin fuzz on the front and weak corrugation, the front of the adult leaf is dark green, and the back is light green. The adult leaf is large. Fruit shape is ovate without sepals, the lenticels are moderately prominent, the peel is gray-brown with a moderate amount of short hairs evenly distributed on the surface of the peel, the color is gray-brown, and it is easy to fall off. The average fruit weight is 98.76 g with maximum fruit weight being 150 g. Soluble solids content is 16.1%, dry matter, total sugar and total acid contents are 19.21%, 10.79% and 1.10%, respectively, and vitamin C content is 171.33 mg•100 g-1. Fruit quality is excellent. The fruit development period is 150 d, it matures in late September in Deyang area of Sichuan province and it's a mid-season-mature variety. The inflorescence type belongs to the dichotomous cyme, each inflorescence has 3 flowers, and the bud break and cane growing ability is strong. It is medium- to-high resistant to PSA, and the occurrence of brown spot and scale insects is slight. The resistance and adaptability are strong. The fruit has very long storage-life, and cold storage life is 120-150 days. Suitable cultivation area is relatively extensive with annual average temperature >15℃, altitude below 1000 meters, slightly acidic soil and well-drained land. It can flower and bear fruit in the third year after establishment with good yield. © 2022, Office of Journal of the Fruit Science. All right reserved.     

Research and utilization progress in banana germplasm resources in China北大核心CSCD

Banana is one of the main fruit crops and important food crops in the world, and it is also an important economic fruit in southern China. China is the border area of the origin of modern bananas, and one of the secondary origin centers as well. China has a history of banana cultivation for more than 2000 years and is the second largest country in banana production and consumption. Banana producing areas in China are mainly concentrated in Guangdong, Guangxi, Hainan, Yunnan, Fujian and Taiwan, with a small amount of cultivation in the south of Sichuan, Guizhou and Tibet. Most cultivated bananas are evolved from two wild species, Musa acuminate and Musa balbisiana, and their interspecific hybridization. The genome of Musa acuminata is called“genome A”, while the genome of Musa balbisiana is called“genome B”. According to the classification value of characteristics, banana cultivars can be divided into genotypes such as AA, AAA, AB, AAB, ABB, AAAA, AAAB, AABB, BB and BBB. Bananas cultivated in China are simply divided into four categories: Cavendish (AAA), Pisang Awak (ABB), Silk (AAB) and Dajiao (ABB). Cavendish banana is planted mostly in China (more than 80%), followed by Pisang Awak (more than 10%). Notably, in China, few people plant and consume Plantain (AAB), which is an important staple food in some area. Banana breeding mainly includes introduction (like Brazil and Williams banana), vegetative line selection (like GCTCV bananas), artificial mutation breeding (like Jiali banana), cross breeding (like Fenza No. 1 and Zhongjiao No. 9 banana), chromosome ploidy breeding, transgenic breeding and gene editing breeding. The introduction method is simple and direct. Our group took the lead in establishing the National Banana Germplasm Resource Garden in 1989. In the future, we should introduce not only high-quality varieties, but also multifunctional and diverse banana varieties to enrich China’s banana market. After introduction, people often get better lines that adapt to Chinese geographical and climatic conditions and planting habits, and then popularize them. Mutation breeding is easy, but the ideal excellent lines can only be obtained through a large number of screening and evaluation. The female flowers of some bananas, like Dajiao and Pisang Awak, have strong fertility, so they are often used as female parents to cross with wild bananas or cultivated varieties with certain fertility. Although sexual hybridization of banana needs a long period and is easy to fail, this method can often create new germplasm with diverse genetic background and relatively controllable traits, which is the most potential and promising method in traditional banana breeding at present. In recent years, researchers in China have created many new hybrid banana germplasm, and it can be predicted that a large number of new hybrid banana varieties will emerge in China in the near future. Banana transgenic and gene editing breeding have strong pertinence. China has made good achievements in the fields of banana transgenic and gene editing. However, as in many other parts of the world, these methods cannot be applied to business at present. At last, other breeding methods like somatic hybridization, rapid breeding and molecular-assisted breeding are rarely used at present. Banana Fusarium wilt and other diseases seriously threaten banana industry in China. At the same time, frequent typhoons and floods, severe frost and poor soil in the main banana producing areas in China also limit the further development of banana industry. Breeding new banana varieties with high yield, high quality and high stress resistance and adaptability is the key to break the bottleneck of banana industry development in China, and it is also a challenge for banana breeders in China. In addition, it is also an important direction to cultivate bananas with high nutrition and health care function, which are suitable for industrial processing or feed. During the last decades, China has made great achievements in banana breeding, but there are still many problems. First of all, banana biodiversity is relatively lacking, with few wild banana resources. Moreover, the careful evaluation of banana germplasm resources is not enough, limiting the utilization of them. Secondly, the main banana varieties in China were bred by introduction and mutation breeding, and only a few were bred by hybridization or other means. Moreover, due to many reasons, there is a lack of varieties with good comprehensive characteristics. Finally, it is difficult to study genes in banana through the forward or reverse genetic means, limiting the molecular research on banana. In the future, we should: (1) Continue to strengthen the collection, evaluation and utilization of global banana germplasm resources, and especially promote banana cross breeding vigorously; (2) Pay attention to the basic research on banana, dig out the key genes related to important economic traits, and analyze their regulatory networks, so as to lay the foundation for creating new banana varieties without transgene through gene editing technology in the future; (3) Continuously develop and upgrade new breeding techniques, promote the integration of various means, and breed efficiently and scientificly; (4) Breed new varieties that are resistant to various diseases and have good comprehensive properties, so as to win the banana defense war. In a word, we have summarized the research results of banana breeding in China in recent years, discussed the methods of banana breeding, the direction of new variety breeding and the main problems, in order to provide reference for banana breeding in China. © 2023 Journal of Fruit Science. All rights reserved.     

Identification of resistance to anthracnose in leaves of grape resources and QTL localization of disease resistance genes北大核心CSCD

【Objective】 Grape anthracnose is one of the main diseases of grape, which mainly infects the fruits, young leaves and new branches of grape, causing fruit rot, shedding, or water loss and shrinkage into stiff fruits. Breeding disease-resistant grape varieties is the most economical, effective, and environmentally friendly long-term control strategy for the prevention of the anthracnose disease. There have been a few studies on the identification of the resistance to anthracnose and the QTL localization of relative disease resistant genes so far. The study aimed to identify the resistance to the anthracnose disease of different grape germplasms and seek for new QTL locus for the resistance and provide germplasm materials and basis for the breeding and research on the disease resistance mechanism. 【Methods】 The indoor ex vivo leaf inoculation method was used to identify and evaluate the resistance to anthracnose in 60 strains of Chinese wild grapes, 122 accessions of V. vinifera and 76 accessions of V. vinifera-V. labrusca, and the hybrid offsprings of Manicure Finger (susceptible)×Ciputao0940 (resistant), and the QTL localization of grape anthracnose resistance was carried out using the genetic map constructed by SNP markers.【Results】 A total of 1 germplasm with high resistance, 43 germplasms with resistance and 75 germplasms with medium resistance were screened out, accounting for 0.39%, 16.67% and 29.07% of the total identified accessions, respectively. There were great differences in the resistance to anthracnose in different germplasm populations. 63.34% of the East Asian population 56.57% of the V. vinifera-V. labrusca population, and 31.15% of the Eurasian population had the resistance to anthracnose. In the identification of anthracnose resistance in Chinese wild grape germplasms, it was found that the resistance of different strains in the same population varied greatly, and the species with strong resistance on the whole included V. davidii, V. pseudoreticulata, V. amurensis, and V. piasezkii. The strong resistance of the strains include Shanputao &, Longyuwanfuye1 &, Duolieye-yingyu, Shanputao- shanyang1807, Mianmaoputao-chayu1955, and Ciputao0940. The resistance of the hybrid offsprings of Manicure Finger (susceptible)×Ciputao0940 (resistant) were distributed in five grades. According to the normality test and single-sample Kolmogorov-Smirnov test based on the resistance level distribution of the F1 population, it was found that the hybrid offsprings of Finger (susceptible) × Ciputao0940 (resistant) showed continuous variation in anthracnose resistance, which was a typical quantitative trait controlled by polygens, and the phenotypic distribution of disease resistance identification results showed a trend of partial normal distribution, which could be analyzed by QTL localization. In the positioning of QTL related to grape resistance to anthracnose, the interval or site of LOD≥3.0 was used as the threshold value for QTL, and when the above conditions were met, the site corresponding to the highest LOD value in the interval was considered to be one QTL of grape anti-anthracnose. In this experiment, a QTL interval associated with grape anthracnose resistance was detected on the 8th linkage group, and the locus with the highest LOD value in this interval was located at 140.682 cM, and the tightly linked label was Maker1675910, which could explain the 14.7% of the phenotypic variation. Based on the gene annotation results of the QTL locus interval, 15 resistance- related genes were screened out, and they were hypothesized to play a role in grape anthracnose resistance. 【Conclusion】 The resistance level of different grape germplasms to anthracnose was clarified, one QTL site against anthracnose was located and 15 resistant-related genes were screened. © 2023 Journal of Fruit Science. All rights reserved.     

A molecular detection and identification method for papaya mealybug （Paracoccus marginatus）, the first recorded invasive pest in Fujian province of China北大核心CSCD

【Objective】Paracoccus marginatus Williams and Granara de Willink is an invasive pest with strong diffusion and fecundity. It has caused serious damage to the papaya industry in Central America, Florida (USA), Guam (USA) and India. Pa. marginatus was first discovered in Fujian Province (Fuzhou and Zhangzhou) in 2017, showing great potential risks to papaya and other fruit crops, as well as flower industry in Fujian province. Because of the small body size and similar morphological characteristics, the morphological identification of mealybugs was inefficient. Rapid molecular identification of different species could be achieved through the use of DNA barcoding technology. Therefore, a technology for rapid molecular identification of Pa. marginatus was established based on the species-specific PCR method. 【Methods】A species-specific PCR method based on ribosomal DNA-28S gene fragment (28S rDNA) was exploited to establish one technology for rapid detection and identification of Pa. marginatus. The additional 10 species of mealybugs (Phenacoccus solenopsis, Dysmicoccus boninsis, Nipaecoccus viridis, Phenacoccus solani, Pseudococcus comstocki, Pseudococcus cryptus, Planococcus lilacinus, Pseudococcus odermatti, Planococcus minor and Phenacoccus madeirensi) were collected in the fields as the contrast. In order to ensure the uniqueness of the source of DNA, the DNA templates were all extracted from one single female adult of these 11 species of mealybugs, respectively. 28S rDNA of the 11 species was amplified by a pair of universal primers (S3660/A335). The obtained partial fragments of 28S rDNA were sequenced. And the phylogenetic tree was established by using a Neighbor-joining (NJ) method. According to the obtained 28S rDNA gene partial sequence of the 11 species and 28S rDNA gene sequences of Paracoccus galzerae in GeneBank database, the sequence alignment and analysis were performed on DNAMAN. 28S rDNA species-specific primers (28S-ParF/ 28S-MarR) for Pa. marginatus were designed by selecting the sites with large differences in the sequence. And then, the specific effects, versatility and sensitivity of the specific primers were examined. 【Results】The comparative results showed that the similarity between Pa. marginatus and Paracoccus marginatus isolate S3-668, KP692333 in the GenBank database was 100%. It was also indicated that the mealybugs were identified as Pa. marginatus by molecular identification. Phylogenetic analysis indicated that Pa. marginatus from Fuzhou and Zhangzhou was clustered in a clade. And that combined with Paracoccus galzerae (inter-species genetic distance is 0.058) to form a clade of the genus Paracoccus. The results of specificity tests showed that all Pa. marginatus specimens could be detected positively and a 446 bp fragment of the 28S rDNA of Pa. marginatus was obtained by the species-specific primers, while there was no cross reactions with other 10 species of mealybugs. The species-specific primers not only had a stable amplification effect on female adults, but also were proved to be applicable for the 2nd instar nymphs and the 3rd instar nymphs. Pa. marginatus from three different regions (Fuzhou and Zhangzhou in Fujian province, Jinghong in Yunnan province) and six different host plants (Carica papaya, Solanum melongena, Plumeria rubra, Solanum tuberosum, Tithonia diversifolia and Duranta erecta) was also successfully detected by the species-specific primers.【Conclusion】Molecular identification of Pa. marginatus first reported in Fujian province was carried out based on 28S rDNA molecular markers. It was proved by experiments that the 28S rDNA species-specific primers had ideal and stable specificity for Pa. marginatus and could be used to identify Pa. marginatus accurately. A rapid molecular detection technique for Pa. marginatus was established based on the species-specific PCR method. The technology has the characteristics of accuracy, rapidity, sensitivity and simplicity. Our present results indicated that the rapid detection technique should be useful in quarantine at ports, in pest detection and in monitoring during transportation of papaya and other fruit tree seedlings, as well as flowers. However, in view of the fact that no other mealybugs of the genus Paracoccus has been reported in China, this study can provide a reference for the molecular identification for the closely related species of Pa. marginatus. © 2019 Journal of Fruit Science     

Effects of nitrogen application rates on the leaf qualityof‘Cabernet Gernischet’in desert areas北大核心CSCD

【Objective】As an essential mineral element in plant growth and development, nitrogen has irreplaceable roles in organ construction, nutritive metabolism, biochemical processes as well as fruit yield and quality. The quality and yield of grapes are greatly influenced by the amount of nitrogen applied. In recent years, the industry of China's wine grape has developed rapidly, but there are problems with unreasonable fertilization in production. The Gansu Corridor has the climatic conditions and geographical resources suitable for producing high-quality wine grapes. However, wine grapes are extensively planted on a sandy loam soil with low organic matter. In the actual production, chemical fertilizers are often applied to ensure the normal growth and development of the grapes. At the same time, water-saving agriculture has become the demand for agricultural development in this area. The aim of our study is to investigate the effects of nitrogen application rates on key enzyme activities and related gene expression during nitrogen metabolism, so as to further provide a theoretical reference for the application of nitrogen in wine grape growing in the Gansu Corridor. 【Methods】The experiment was carried out in a 10-year-old‘Cabernet Gernischet’vineyard of the Mo Gao located in Wuwei City from 2014 to 2015. All the grapevines were planted from west to east with simple hedge-shape. The planting spacing was 0.7 m×3.0 m. The area of the plot was about 240 m2, and each plot contained 40 plants. During the test period, the irrigation was carried out according to the“Wuwei Mo Gao Brewing Grape Drip Irrigation Water Distribution Quota”, which formulated by the research team. The irrigation amount in the bud break stage was 675 m3·hm-2, the flowering stage was 900 m3·hm-2, the first berry swell period was 900 m3·hm-2, the secondary shoot growth period was 150 m3·hm-2, and the second berry swell period was 600 m3 · hm- 2, and overwintering water was 1 275 m3 · hm- 2. The total irrigation amount during the whole growth period was 4 500 m3·hm-2. Five different application amounts of nitrogen (0 kg·hm-2, 150 kg·hm-2, 300 kg·hm-2, 450 kg·hm-2 and 600 kg·hm-2, characterized as CK、N1、N2、N3 and N4, respectively) were applied with a completely randomized block. Urea was used as external nitrogen and applied with water. The 750 kg·hm-2 of calcium superphosphate was applied before the first irrigation during the soil excavation. The 825 kg·hm-2 of potassium sulfate was applied in fruit color-changing period. Effects of nitrogen application rates on total nitrogen content, soluble protein content, key enzyme activities including nitrate reductase(NR), glutamine synthetase(GS), glutamate synthase(GOGAT) and glutamate dehydrogenase(GDH) as well as the related gene expression levels in leaves (VvNR1, VvGS1, VvGOGAT1 and VvGDH1) were determined at different developmental stages (5th day before anthesis, 20th day after anthesis, 50th day after anthesis, 80th day after anthesis). Ten to fifteen leaves were collected from each treatment. Fresh leaves were punched out with a punch and 1.0 g was weighed for determination of soluble protein content and enzyme activity assay with 3 replicates. The new leaves without pests and diseases on the top of the current shoots were selected to extract RNA. 2.0 g of grape leaves wrapped in tin foil were placed in a liquid nitrogen tank and stored in arefrigerator at -80℃ for RNA extraction. 【Results】The results showed that nitrogen application significantly increased the net photosynthetic rate in leaves. The treatment of N2 significantly increased leaf area and the total nitrogen content in leaves in comparison with CK 5th day before anthesis, 20th day after anthesis and 80th day after anthesis. The soluble protein content increased by nitrogen application in leaves on 80th day after anthesis. The NR activity in leaves showed an increasing trend with the increase of nitrogen application in the range of 0 to 300 kg on 5th day before anthesis, 20th day after anthesis and 80th day after anthesis. The GS activity in leaves increased significantly by N2 treatment on 5th day before anthesis, 50th day after anthesis and 80th day after anthesis, which were 1.66, 1.25 and 1.34 times more than the control, respectively. The GOGAT activity in leaves increased significantly by N2 treatment on 5th day before anthesis and 80th day after anthesis, 0.53 and 0.42μmol·g-1·min-1, respectively. Compared with CK, N2 and N3 treatments could improve the GDH activity in leaves during the whole growing period. The expression level of VvNR1 in N2 treatment was significantly higher than CK and other nitrogen treatments on 5th day before anthesis, 20th day after anthesis and 80th day after anthesis. VvGS1 was significantly up-regulated by N1 and N2 on 5th day before anthesis, which was up-regulated by 142.33% and 283.47% in comparison with CK, respectively. VvGDH1 was up-regulated during the whole growing period after nitrogen application. With N2 treatment, fruit soluble sugar, the ratio of sugar to acid, tannins, anthocyanin content reached the maximum, the titratable acid content was the lowest, the yield was at a medium level. 【Conclusion】The results suggested that different nitrogen application rates affected the expression of VvNR1, VvGS1, VvGOGAT1 and VvGDH1 genes in leaves, thereby improving leaf nitrogen metabolism. In addition, the nitrogen application with 300kg·hm-2 (N2) among all the treatments significantly promoted the accumulation of nitrogen in leaves during the late growth period. At the same time, it promoted the increase of leaf area and net photosynthetic rate, and improved the fruit quality. © 2019 Journal of Fruit Science     

Detection and differential analysis of fruit organic acids among different local wrinkled papaya varieties(Chaenomeles speciosa ) by GC-MS北大核心CSCD

【Objective】Organic acid plays a key role in affecting fruit flavor by changing acid-sugar ratio. And GC-MS is also an important detecting platform to inspect fruit organic acids due to its stable, sensitive and accurate features. With methyl ester derivatization, the objective organic acids could be effectively detected for their reduction of ingredient polarity. To provide the basic data for Chaenomeles speciosa (Sweet) Nakai fruit quality improvement, the the organic acid inspection of the fruit sampleswas carried out from 10 main producing areas in China and their compositions and contentswere disclosed by extracting with methal, derivating with methyl esterification and detecting by means of GC-MS.【Methods】In this study, 10 local varieties were used as materials that were collected from 10 main producing areas in China. After methanol extraction and methyl-ester derivatization, the compositions and contents of organic acids with each sample were comprehensively determined by GC- MS. The derivatives were analyzed by a Shimadzu GC-MS 2010 Qplus with a Rxt-5MS weak polar capillary MS column(30 m × 0.25 mm, 0.25 μm, Shimadzu Technology). Helium was used as the carrier gas at 0.87 mL · min- 1 with a split ratio of 53:1 for the testing solution. The GC-MS detecting time was 35 min. Qualitative retrieval was conducted with similarity searching in NIST08 and NIST08S coupled with Kovats Reservation Index(RI value) matching and quantitative analysis was performed by an external standard method and the ingredient peak responding value was adjusted according to the n-alkanes mixed standards that came from USA O2Si calibration standards company. The difference in objective organic acids of all the 10 local variety samples was done through the Excel 2007 software and the Hierarchical Cluster Analysis(HCA) of organic acid composition among different samples was completed with SPSS20.0.【Results】Six standards for organic acids including malic acid, citric acid, oxalic acid, succinic acid, fumaric acid and oleic acid as well as their gradient regression equations showed that there was a high correlation between the standard concentration and their component peak area(R2 ≥ 92.9%). All baselines of the TICs were stable and all the component peaks were evenly distributed during the detecting period and their resolution was high. So the method for extracting by methanol, derivating by methyl ester and detecting by GC-MS was stable and reliable. A total of 43 organic acids including 9 short-chain carboxylic acids, 22 long-chain fatty acids, 4 aromatic dicarboxylic acids, 4 mono-basic phenol acids and 2 amino acids were identified from the 10 fruit samples of different producing areas in China. The top 10 organic acids with the highest contents were dl-malic acid, citric acid, hexadecanoic acid, 9,12-octadecadienoic acid, 9-octadecenoic acid, (+/-)-10-hydroxy-octadecanoic acid, levulinic acid, stearic acid, 9,10-dihydroxy-octadecanoic acid and benzoic acid, respectively. There were 33 common ingredient peaks among the total 10 local varieties and their total contents of organic acids were between 85.02-170.76 mg·g-1. From high to low content, it showed like this: Linyi of Shandong > Jinghong of Yunnan > Zheng’an of Guizhou > Chun’an of Zhejiang > Qijiang of Chongqing> Changyang of Hubei > Xuancheng of Anhui > Yilong of Sichuan > Nanning of Guangxi > Baihe of Shaanxi. The total organic acid content had an extremely significant positive correlation with the long-chain fatty acids, mainly including hexadecanoic acid, 9,12-octadecadienoic acid and 9-octadecenoic acid; a significant positive correlation with the short-chain carboxylic acids, mainly consisting of dl-malic acid and citric acid; a negative correlation with the aromatic carboxylic acids, mainly containing benzoic acid. Analysis of the cluster according to 33 common components showed that all the fruit samples were classified into 4 categories when their clustering distance was 5: Yilong of Sichuan, Xuancheng of An’hui, Baihe of Shaanxi, Nanning of Guangxi, and Changyang of Hubei were clustered into the first group; Qijiang of Chongqing and Chun’an of Zhejiang were clustered into the second branch. Zheng’an of Guizhou and Linyi of Shandong were clustered into the third group, and Jinghong of Yunnan was alone clustered into the fourth group. The Hierarchical Cluster Analysis (HCA) coupled with the total organic acid content showed that Zheng’an of Guizhou and Linyi of Shandong belonged to the high-acid varieties, Qijiang of Chongqing and Chun’an of Zhejiang were the middle-acid varieties, and Yilong of Sichuan, Baihe of Shaanxi and Nanning of Guangxi belonged to the low-acid varieties.【Conclusion】Compared with the acid-base titration method and HPLC, GC-MS method not onlywas more stable, sensitive and accurate, but also could realize a qualitative identification of more chemical components. So it was much better to be used in the determination of total organic acid contents in fruits and their derived products. The results showed that there was a small difference among the different local varieties and an obvious difference existed in organic acid compositions and contents among the samples from different producing areas in China. And dl-malic acid and citric acid were the main components in most of C. speciosa fruit samples from 10 producing areas in China. Therefore, it belonged to the fruit type of malic acid accumulating mode. © 2019 Journal of Fruit Science     

Effects of exogenous cyanide on root physiology and metabolism of peach seedlings北大核心CSCD

【Objective】Peach (Prunus persica) is an economically important fruit crop worldwide. With the increasing demand and the reduced cultivated land acreage of peach, replant problem (also known as replant disease) has become increasingly prominent, and has been causing severe economic losses. Autotoxicity is a special kind of allelopathy, and is considered to be a major factor resulting in the prevalence of peach replant problem. Cyanide (CN-) is a major autotoxin that causes peach replant problem, but the information on physiological and metabolic responses of peach plants under CN- treatment is quite limited. Thus, the specific responsive mechanisms of peach plants to CN- are worthy of in-depth exploration. The study aimed to investigate the effects of CN- treatment on the morphological, physiological, and metabolic parameters in roots of peach seedlings, so as to provide new insights into the response mechanisms of peach plants to CN- treatment. 【Methods】The natural root environment of dead and living trees was investigated in the peach orchard of Huazhong Agricultural University. The effects of exogenous CN- treatment on root growth and seed germination were assessed on peach germinatedseeds (treated with 0, 0.25, 0.5, and 1.0 mmol•L-1 CN-) and lettuce seeds (treated with 0 and 0.5 mmol•L-1 CN- ). The peach root tips treated with 0 and 0.5 mmol • L-1 CN- were subjected to anatomical assessments using paraffin sectioning and staining (including transverse and longitudinal sections). The contents of H2O2 and MDA, as well as the activities of CAT, POD, and SOD from 0 and 0.5 mmol•L-1 CNstressed peach roots were detected. The expression levels of CAT, POD, and SOD-encoding genes were tested using qRT-PCR. To further understand the CN- -induced metabolic changes, peach roots treated with 0 and 0.5 mmol • L-1 CN- for 5 d were subjected to gas chromatography-mass spectrometry (GCMS) analysis. 【Results】The CN- was mainly distributed in 0-40 cm soil layer, and the content was significantly higher in the soil with dead trees than with living trees. The CN- content in soil was predominantly detected adjacent to peach roots, and gradually decreased with the distance from peach roots. The CN- contents showed an upward trend year by year in the bulk soils with the dead and living trees, where the dead trees contained more CN- than the living trees. The CN- contents varied in different size of peach roots, the fine roots (Φ < 5 mm) contained more CN- than the middle size (5 mm ≤ Φ ≤ 10 mm) and the large size roots (Φ > 10 mm). We evaluated the effect of different CN- concentrations (0, 0.25, 0.5, and 1.0 mmol•L-1) on the growth performance of peach germinated-seeds. The result showed that 0.25 mmol • L-1 CN- treatment boosted root growth, while 0.5 and 1.0 mmol • L-1 inhibited root growth with decreased root length and lateral root numbers. The allelopathy sensitivity index indicated that the effects of CN- treatment on peach growth in a concentration-dependent manner, showing low concentration promoted growth but high concentration inhibited it. Additionally, with 0.5 mmol•L-1 CNtreatment, the transverse and longitudinal sections of the root tip showed a severely wrinkled root epidermis, ruptured root cortex cells, and larger intercellular spaces. 0.5 mmol•L-1 CN- treatment also significantly inhibited lettuce seed germination and biomass. The contents of H2O2 and MDA in peach roots significantly increased, and the activities of SOD, POD, and CAT, as well as their respective encoding genes expression, significantly increased with 0.5 mmol•L-1 CN- treatment. The GC-MS analysis showed that 0.5 mmol • L-1CN- treatment dramatically increased contents of numerous amino acids, including proline, glycine, serine, asparagine, alanine, glutamate, GABA etc. Moreover, CN- treatment significantly affected carbohydrate levels in peach roots. 【Conclusion】The CN- contents were associated with the distribution and size of plant roots, and the decomposition of plant residuals. Exogenous CNsupply markedly retarded peach root growth. CN- feeding also gave rise to oxidative stress, reflecting by the increased ROS and MDA levels, and antioxidant enzyme activities. CN- supplementation also induced metabolic reprogramming, displaying a disorder of amino acid and carbohydrates metabolism. © 2022, Office of Journal of the Fruit Science. All right reserved.     

Monokaryons Fruiting and Fruit body color of Flammulina velutipes

Thirteen kinds of yellow and three kinds of white monokaryons were isolated from mycelium of eight Flammulina velutipes strains using the monokaryon protoplast technique. Of these, five yellow and two white monokaryons produced monokaryotic fruit bodies. Clear differences were observed in the color of the different yellow monokaryotic fruit bodies, as well as between the pilei and stipes of individual yellow monokaryotic fruit bodies, suggesting that the yellow color is under the control of multiple alleles.     

保护地专用春甘蓝新品种‘中甘56’

 ‘Zhonggan 56’is a spring cabbage hybrid between dominant genic male sterile line DGMS726-3 and self-incompatible inbred line 0445-1-1-2,special for protected cultivation. It takes about 46 days from transplant to harvest when planted in the greenhouse in north China as the spring cabbage. The head is round in shape and green in color,with the weight of around 1.0 kg. The head is crisp and tender,with high quality. It is tolerant to the low temperature,low light,and premature bolting. It is suitable for protected cultivation in spring in Hebei,Shaanxi,Shandong,Henan,Jiangsu,etc.     

Sequence analysis,prokaryotic expression and antiserum preparation of coat protein gene of Actinidia virus A in Sichuan province北大核心CSCD

【Objective】The purpose of the research was to study the occurrence and molecular diversity of Actinidia virus A (AcVA), so as to provide scientific basis for the rapid detection, scientific prevention and control of AcVA and the variety breeding of kiwifruit in China.【Methods】Total RNA was extracted from kiwifruit leaves by CTAB (Cetyl Trimethyl Ammonium Bromide). Nested- PCR was used to amplify AcVA CP gene sequence. The first round PCR amplification was performed by using primers AcVA- 1F (5’- ATGAATCGTTCGAGCA TAGGT- 3’) and AcVA- 1R (5’- TGCGAACATGGTCCCACACTTA-3’), and the pair of primers was designed according to the full length of AcVA sequence, and the amplified fragment was 888 bp that included the complete CP gene sequence. The reaction was conducted under conditions of initial 5 min denaturation at 94 ℃, 34 cycles of 94 ℃ for 60 s, 54 ℃ for 60 s, 72 ℃ for 60 s and extension for 10 min at 72 ℃. Then, 1 μL PCR product was used as template for the second round of PCR amplification with the primers AcVA- 2F (5’- ATGGCAAAGAATATCTCAAG-3’) and AcVA-2R (5’-CTATATTTCAACAGCCTGC-3’). PCR was performed using the following parameters: one cycle at 94 ℃ for 5 min, 34 cycles at 94 ℃ for 30 s, 54 ℃ for 30 s, and 72 ℃ for 40 s, and extension for 10 min at 72 ℃. The BLAST algorithm was used to search the NCBI GenBank (http://www.ncbi.nlm.nih.gov/) databases for homologous sequences and ascertain the identity of target gene. DNAMAN was used to analyze the AcVA CP gene sequence, and MegAlign was used to analyze the sequence identity. The phylogenetic tree was constructed using the Neighbor-Joining (NJ) method in MEGA 6.0. The restriction enzymes Bam HⅠ and Sal Ⅰ were added to the corresponding end of the AcVA CP gene sequence, respectively. The PCR purified products and pET28a vector were digested by Bam HⅠ and Sal Ⅰ, after that they were ligated with T4 DNA ligase (TaKaRa) and transferred into E. coli (Escherichia coli) strains DH5á (TaKaRa), and finally plated onto LB (Luria-Bertani) agar containing Kana (Kanamycin). The expression strain BL21 containing the recombinant plasmid was cultured at 37 ℃ overnight, and transferred to a new medium at a 10% inoculum on the second day, until OD600 reached 0.4-0.6, IPTG (Isopropyl β-D-Thiogalactoside) was added to a final concentration of 0.2, 0.4, 0.6, 0.8, 1.0 mM, and incubated at 16 ℃ overnight. The expressed protein was purified and then anti-AcVA-CP antibody was obtained from a rabbit. The optimal titer of the antiserum was tested by Western blot.【Results】The complete CP gene sequences of AcVA Sichuan isolates were cloned by nested-PCR and named as AcVA-DJY4, AcVA-HYZ1 and AcVA-WBS12, respectively. In the study the frequency of AcVA in Sichuan province was also counted. The full length of the CP gene sequence was 597 bp, encoding 198 amino acids. Based on the comparison of the nucleotide sequence and the deduced amino acid sequence of CP gene of the AcVA isolates, the nucleotide identity between the AcVA isolates from Sichuan province ranged from 86.9% to 88.3%, and the identity of the encoded amino acids ranged from 96.0 to 96.5%. The CP genes of three AcVA Sichuan isolates shared 87.9%-90.8% nucleotide identity and 94.9%-97.5% amino acid identity with the Actinidia virus A isolate TP7-93A (AcVA-TP7-93A) from New Zealand and the Actinidia virus A isolate Haenam (AcVA-Haenam) from South Korea. Phylogenetic analysis based on nucleotide sequence of AcVA CP gene showed that AcVA-HYZ1 was clustered with AcVA-Haenam (Group I), and AcVA-WBS12 was clustered with AcVA-TP7-93A (Group II), but AcVA-DJY4 was an independent branch. Phylogenetic analysis based on amino acid sequence of AcVA CP gene showed that AcVA-WBS12 was a single branch, AcVA-DJY4 and AcVA-HYZ1 were clustered into one group (Group I), and the AcVA-Haenam reported in South Korea and the AcVA-TP7-93A reported in New Zealand were clustered into another group (Group II). The results of the phylogenetic analyses indicated that there were significant differences among the AcVA isolates. The prokaryotic expression plasmid pET28a-AcVA-DJY4-CP was successfully constructed. The target fusion protein (27 kDa) was highly expressed in E. coli induced by 0.6 mmol · L- 1 IPTG at 16 ℃. The expressed protein was purified and retrieved and then used to immune rabbits and the corresponding specific antiserum was prepared. Western blot analysis confirmed that the antiserum reacted strongly and specifically with the CP of AcVA-DJY4, with the optimal titer of the antiserum being up to 1:5 000.【Conclusion】Three AcVA Sichuan isolates were obtained for the first time, enriching the sequence diversity of the AcVA CP gene sequences. In the study, the optimal conditions were explored for prokaryotic expression and specific antisera was prepared for detection of AcVA-DJY4-CP. Western blot analysis showed that the antiserum could be used for the detection of AcVA in the kiwifruit producing districts. These results can also provide a technical support for the rapid detection, scientific prevention and control of virus disease in kiwifruit plant and the breeding of kiwifruit varieties. © 2019 Journal of Fruit Science     

Cross-breeding and Selection of Flammulina velutipes Hybrid Strains for Industrial Cultivation

White Flammulina velutipes strains FM0 F21,F10 and F3-W were selected as the parental strains in a single-spore cross-breeding experiment.Thirty basidiospore-derived monokaryons were selected randomly from each parental strain,and mating was carried out according to the mating groups:FM×F21,FM×F3-W and F3-W×F10.Integrative analysis revealed that hybrid progenies from the FM×F21 mating group exhibited the highest mating rate (79%).However,only 59.2% of these hybrids produced measurable fruit body yields c...