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     

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     

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.     

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     

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     

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.     

Factors Affecting Extraction of Ganoderma lucidumPolysac-charide Using Ultrasound and Ultrasound+Cellulase Methods

Ganoderma lucidumhas been used as atraditional medicine in China for twomillennia,both as a general tonic and forbuilding up bodily resistance to disease[1].Polysaccharides are one of the most i mportantand effective components of theG.lucidumfruit body,and are widely used in medicinesand health foods.Decocting,boiling or steamdistillation are the main methods commonlyused to extract polysaccharide.These methodsare usually ti me-consuming and,becauseextraction efficiencies are low,result in c…     

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     

Risk assessment of dietary intake of pesticide residues in kiwifruit北大核心CSCD

【Obiective】Risk assessment of dietary exposure to pesticide residues in kiwifruit and quantifiction of the dietary risk levels of commonly used pesticides provide references for safe production and guidance for consumption of the fruit, food safety supervision, and revision of the Maximum Residue Limits (MRLs) of kiwifruit.【Methods】Based on detection of the residues of 66 pesticides in 61 kiwifruit samples from a major producing area, chronic dietary intake risk (%ADI) and acute dietary intake risk (%ARfD) of pesticide residues in these samples were assessed. Based on the veterinary drug residue risk ranking matrix constructed by the British Veterinary Drug Residues Committee, the risk of th epesticides and samples was ranked by integrating kiwifruit consumption and pesticide toxicity, frequency of use and residue level, and maximum residue limit estimates (eMRL) were calculated using allowable daily intake (ADI) values, large portion consumed (LP), and body weight (bw). The study will provide a reference for the regulation of the maximum residue limit (MRL) for the corresponding pesticides.【Results】(1)Among the 62 pesticides, a total of 21 pesticides were detected, and they were low-toxic pesticides except for chlorpyrifos, deltamethrin, cypermethrin and cyhalothrin, which were moderately toxic; (2) Using the pesticide toxicology data, acceptable daily intake (ADI) and acute reference does (ARfD), residual data and kiwifruit consumption data, the risk assessment of the 21 pestcides detected showed that the chronic dietary intake (%ADI) of each pesticide inkiwifruitranged from 0.000 01% to 0.016 04%. All the 21 pesticides detected but acetamiprid and chlorpyrifos without ARfD information had an acute dietary intake (%ARfD) ranging from 0.01% to 26.20%. The acute dietary intake risk difference between different pesticides was significantly. (3) According to the residual risk score, the 21 pesticides detected were medium- to low-risk pesticides. The risk scores for deltamethrin and chlorpyrifos were 16.5 and 16.1 ie(15≤S<20), respectively, which were in the medium-risk range. The risk scores of cypermethrin, pyrimidine, buprofezin, cyhalothrin and difenoconazole were between 12.1 and 12.4, and the risk scores of 14 pesticides including procymidone and chlorpyrifos ranged from 8.0 to 9.3 (S< 15). All of them were low-risk pesticides. Among the 61 kiwifruit samples, 45.9% of the samples were in a very low risk area with a pesticide residue risk index (RI) below 5; 34.4% of the samples were in a low risk range with a pesticide residue RI between 5 and 10; and 18.0% of the samples were in a medium risk range with a pesticide residue RI of 10 and 15; (4) At present, there were few standard pesticides in kiwifruit. Among the 21 pesticides detected, only carbendazim, acetamiprid, chlorpyrifos, deltamethrin, and cyhalothrin had maximum residue limit (MRL) in kiwifruit or berries and other small fruits in GB 2763—2016, while 76.2% the pesticides had not a limit value. Compared with eMRL, the MRL values of the five pesticides was a more strict parameter related to limitation of quantities. For example, the eMRL of carbendazim was 6.6 times that of MRL; the eMRL of acetamiprid was 3.8 times that of MRL; the eMRL of cyhalothrin was 10.9 times that of MRL; the eMRL of deltamethrin 21.9 times that of MRL; and the eMRL of chlorfenuron was 153 times that of MRL. Among the 21 pesticides detected, carbendazim, acetamiprid, cyhalothrin, deltamethrin and chlorpyrifos had MRLs, and azoxystrobin, chlorfenapyr, malathion, and procymidone had no necessecity to formulate MRL. 12 pesticides including thiamethoxam, imidacloprid, thiophanate- methyl, tebuconazole, propiconazole, prochloraz, difenoconazole, buprofezin, trifloxystrobin, chlorpyrifos, cypermethrin and chlorothalonil had no MRLs.【Conclusion】The pesticides detected were all middle- risk or low- risk pesticides, and the acute and chronic dietary risks of the 21 pesticides were acceptable. At the same time, 98.4% of the 61 samples were at medium, low or very low risk. Therefore, the kiwifruit in the major producing area was relatively safe. It was recommended to develope the MRLs of 12 pesticides including thiamethoxam and imidacloprid for in kiwifruit. © 2019 Journal of Fruit Science     

Effects of radiation from 188Re on smooth muscle cell proliferation

AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β^-particles emission from ¹⁸⁸Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by ¹⁸⁸Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [³H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of ¹⁸⁸Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from ¹⁸⁸ Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G₀/G₁ arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.     

Effect of L-Arg on plasma content of endothelin and expression of c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy

AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration.     

多效唑对猕猴桃离体试管苗生长及内源激素的影响

多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。     

Proteomic analysis between pathological scars and normal skin

AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.     

Compositional and Functional Properties of Saskatoon Berry and Blueberry

Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.     

Cryopreservation of shoot apices of hawthorn in vitro cultures originating from East Asia

The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.     

Coupling past management practice and historic landscape change on John F. Kennedy Space Center,Florida

Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere.     

XBP-01 accelerated apoptosis induced by oxidized low density lipoprotein in vascular smooth muscle cells

AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis.     

Metallothionein inhibits homocysteine-induced proliferation of rat vascular smooth muscle cells

AIM:To investigate the effect of metallothionein(MT) on proliferation of rat vascular smooth muscle cells (VSMCs) stimulated by homocysteine and its mechanism. METHODS:VSMCs proliferation was measured by [³-H]-TdR incorporation, mitogen-activated protein kinase(MAPK)activity were determined by immunoprecipitation method, the intracellular contents of MT and malondialdehyde (MDA)were assayed by -hemoglobin saturation method and TBA reaction, respectively, and lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. RESULTS:Hcy(10^-6-10^-4 mmol/L) stimulated [³-H]-TdR incorporation by the VSMCs in a concentration-dependent manner. Compared with control, [³-H]-TdR incorporation in VSMCs treated with 0.1 mmol/L Hcy was increased by 4.2 fold (P＜0.01). Meanwhile, Hcy enhanced MAPK activity, MDA formation and LDH release (P＜0.01)in a concentration-dependent manner. Treatment of VSMCs with MT alone did not change above parameters, compared with control. However, MT (10^-6-10^-4 mol/L)attenuated significantly Hcy-stimulated proliferation of VSMCs (P＜0.01)in a concentration-dependent manner. And MT inhibited obviously Hcy-induced activation of MAPK activity, MDA formation and LDH release. Preincubation of VSMCs with 0.5 mmol/L ZnCl₂ for 6 h induced an increase cellular MT content by 5.7-fold (P＜0.01). The MT-overexpressed VSMCs resisted Hcy-stimulating action on MAPK activity, MDA formation and LDH leakage (P＜0.01). CONCLUSION:These results show that MT has an inhibitory effect on Hcy-induced VSMCs proliferation, and that MT could inhibit Hcy-stimulated MAPK activity and lipid peroxidation.     

The effect of exposure on landscape scale soil surface temperatures and species distribution models

Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations, dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme temperatures (summer maximums, winter minimums). The correlation (r ²) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for 37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain the patchy distribution of many species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.