Establishment of an efficient regeneration and genetic transformation system for Malus prunifolia Borkh. ‘Fupingqiuzi’

Malus prunifolia Borkh. ‘Fupingqiuzi’ has significant ecological and economic value and plays a key role in germplasm development and resistance research. However, its long juvenile phase and high heterozygosity are barriers to the identification of ‘Fupingqiuzi’ progeny with excellent traits. In-vitro regeneration techniques and Agrobacterium-mediated genetic transformation systems can efficiently produce complete plants and thus enable studies of gene function.However, optimal regeneration and...     

Cloning and genetic transformation of a novel rice gene OsAPT2

A novel rice gene OsAPT2,which encodes a putative adenine phosphoribosyl transferase(APRT),was cloned.Its full-length cDNA is 1125bp,composing an ORF encoding 212 amino acid residues and a stop cordon,a 5' UTR of 123 bp and a 3' UTR of 363 bp.The sequence data have been submitted to the DDBJ/EMBL/GenBank databases(accession number:AY238894).The deduced amino acid sequence of OsAPT2 is highly homologous to those of previously reported APRTs.The genomic OsAPT2 gene contains 7 exons and 6 introns.Its total length is 4758 bp.Then,an antisense expression vector of the full-length OsAPT2 cDNA was constructed and transformed into rice variety Taibei309 by Agrobacterium tumefaciens mediated transformation method.In total,650 T0 transgenic plants were obtained based on both antibiotic screening and specific PCR identification.One hundred individuals of them were selected and planted in Hainan Island.From those 11 male sterile lines with seed-setting rate lower than 3% in bagged spike were obtained.Results suggest that OsAPT2 is involved in male sterility.Nine of the 11 male sterile lines were constitutive sterile lines;two of the 11 male sterile lines were thermo-sensitive genic male sterile lines,which may be useful in hybride rice breeding.     

Yield gap and resource utilization efficiency of three major food crops in the world——A review

Yield gap analysis could provide management suggestions to increase crop yields,while the understandings of resource utilization efficiency could help judge the rationality of the management.Based on more than 110 published papers and data from Food and Agriculture Organization (FAO,www.fao.org/faostat) and the Global Yield Gap and Water Productivity Atlas (www.yieldgap.org),this study summarized the concept,quantitative method of yield gap,yield-limiting factors,and resource utilization efficiency of the three major food crops (wheat,maize and rice).Currently,global potential yields of wheat,maize and rice were 7.7,10.4 and 8.5 t ha~(–1),respectively.However,actual yields of wheat,maize and rice were just 4.1,5.5 and 4.0 t ha~(–1),respectively.Climate,nutrients,moisture,crop varieties,planting dates,and socioeconomic conditions are the most mentioned yield-limiting factors.In terms of resource utilization,nitrogen utilization,water utilization,and radiation utilization efficiencies are still not optimal,and this review has summarized the main improvement measures.The current research focuses on quantitative potential yield and yield gap,with a rough explanation of yield-limiting factors.Subsequent research should use remote sensing data to improve the accuracy of the regional scale and use machine learning to quantify the role of yield-limiting factors in yield gaps and the impact of change crop management on resource utilization efficiency,so as to propose reasonable and effective measures to close yield gaps.     

Role of flavonoids in plant interactions with the environment and against human pathogens — A review

Flavonoids are widely-distributed polyphenolic secondary metabolites with diverse biological activities in plants and benefit human health as protective dietary agents. They participate in plants' responses to harsh environmental conditions and effectively regulate the cell differentiation and growth. In plants, the majority of their functions are attributed to their strong antioxidative properties. Similarly, dietary flavonoids protect the human body against free radicals which are associated with the development of cancer and atherosclerosis. Plants rich in polyphenols have been used to cure various diseases because of their antibacterial, antiviral, antifungal and anticancer properties. This review summarizes the up-to-date research trends and development on flavonoids and its derivatives, working mechanisms and potential functions and applications particularly in relation to plant protection and human health. Towards the end, notable concluding remarks with a close-up look at the future research directions have also been presented briefly.     

The causes and impacts for heat stress in spring maize during grain filling in the North China Plain——A review

High-temperature stress(HTS) at the grain-filling stage in spring maize(Zea mays L.) is the main obstacle to increasing productivity in the North China Plain(NCP). To solve this problem, the physiological mechanisms of HTS, and its causes and impacts, must be understood. The HTS threshold of the duration and rate in grain filling, photosynthetic characteristics(e.g., the thermal stability of thylakoid membrane, chlorophyll and electron transfer, photosynthetic carbon assimilation), water status(e.g., leaf water potential, turgor and leaf relative water content) and signal transduction in maize are reviewed. The HTS threshold for spring maize is highly desirable to be appraised to prevent damages by unfavorable temperatures during grain filling in this region. HTS has negative impacts on maize photosynthesis by damaging the stability of the thylakoid membrane structure and degrading chlorophyll, which reduces light energy absorption, transfer and photosynthetic carbon assimilation. In addition, photosynthesis can be deleteriously affected due to inhibited root growth under HTS in which plants decrease their water-absorbing capacity, leaf water potential, turgor, leaf relative water content, and stomatal conductance. Inhibited photosynthesis decrease the supply of photosynthates to the grain, leading to falling of kernel weight and even grain yield. However, maize does not respond passively to HTS. The plant transduces the abscisic acid(ABA) signal to express heat shock proteins(HSPs), which are molecular chaperones that participate in protein refolding and degradation caused by HTS. HSPs stabilize target protein configurations and indirectly improve thylakoid membrane structure stability, light energy absorption and passing, electron transport, and fixed carbon assimilation, leading to improved photosynthesis. ABA also induces stomatal closure to maintain a good water status for photosynthesis. Based on understanding of such mechanisms, strategies for alleviating HTS at the grain-filling stage in spring maize are summarized. Eight strategies have the potential to improve the ability of spring maize to avoid or tolerate HTS in this study, e.g., adjusting sowing date to avoidHTS, breeding heat-tolerance varieties, and tillage methods, optimizing irrigation, heat acclimation, regulating chemicals, nutritional management, and planting geometric design to tolerate HTS. Based on the single technology breakthrough, a comprehensive integrated technical system is needed to improve heat tolerance and increase the spring maize yield in the NCP.     

A Method Suitable for Extracting Genomic DNA from Animal and Plant——Modified CTAB Method

[Objective] The study aimed to introduce a rapid and effective method that is suitable for extracting genomic DNA from animal and plant. [Method] The genomic DNAs were extracted from tender leaves of 24 peanut cultivars and from the liver,lung and kidney of white mouse through the specifically modified CTAB method. The DNAs were run on agarose gel,next detected by DNA/Protein analyzer. Finally PCR amplification was conducted to detect the quality of DNAs extracted using the modified CTAB method. [Result] The clear and orderly bands were observed in gel detection,and the values of OD260/OD280 for DNAs extracted via modified CTAB method were between 1.77-1.83. The DNAs performed well in PCR amplification. [Conclusion] The DNAs extracted by modified CTAB method could satisfy the requirement of PCR amplification.     

A Method Suitable for Extracting Genomic DNA from Animal and Plant——Modified CTAB Method

[Objective] The study aimed to introduea a rapid and effective method that is suitable for extracting genomic DNA from animal and plant. [Method] The genomic DNAs were extracted from tender leaves of 24 peanut cuhivars and from the liver, lung and kidney of white mouse through the spe-cifically modified CTAB method. The DNAs were run on agarose gel, next detected by DNA/Protein analyzer. Finally PCR amplification was conducted to detect the quality of DNAs extracted using the modified CTAB method. [Result] The clear and orderly bands were observed in gel detection, and the val-ues of OD260/OD280 for DNAs extracted via modified CTAB method were between 1.77 - I. 83. The DNAs performed well in PCR amplification. [Conclu-sion] The DNAs extracted by modified CTAB method could satisfy the requirement of PCR amplification.     

Simulation Modeling in Plant Breeding： Principles and Applications

Conventional plant breeding largely depends on phenotypic selection and breeder＇s experience, therefore the breeding efficiency is low and the predictions are inaccurate. Along with the fast development in molecular biology and biotechnology, a large amount of biological data is available for genetic studies of important breeding traits in plants, which in turn allows the conduction of genotypic selection in the breeding process. However, gene information has not been effectively used in crop improvement because of the lack of appropriate tools. The simulation approach can utilize the vast and diverse genetic information, predict the cross performance, and compare different selection methods. Thus, the best performing crosses and effective breeding strategies can be identified. QuLine is a computer tool capable of defining a range, from simple to complex genetic models, and simulating breeding processes for developing final advanced lines. On the basis of the results from simulation experiments, breeders can optimize their breeding methodology and greatly improve the breeding efficiency. In this article, the underlying principles of simulation modeling in crop enhancement is initially introduced, following which several applications of QuLine are summarized, by comparing the different selection strategies, the precision parental selection, using known gene information, and the design approach in breeding. Breeding simulation allows the definition of complicated genetic models consisting of multiple alleles, pleiotropy, epistasis, and genes, by environment interaction, and provides a useful tool for breeders, to efficiently use the wide spectrum of genetic data and information available.     

Genetic bases of improved soybean cultivars released from 1923 to 2005 in China—A historical review

Improved soybean cultivars are cultivars released from a scientific breeding program in China in contrast to the historical landraces kept by farmers from their own seed lots. The pedigree data of 1300 soybean cultivars [Glycine max (L.) Merr.] released in China from 1923 to 2005 were collected, checked, and corrected. These cultivars traced back to 670 nuclear and 344 cytoplasmic ancestors; 45% (50%) of the nuclear (cytoplasmic) germplasms were from Eco-region I, 23% (26%) from II, 7% (10%) from III, 4% (5%) from IV, 1% (1%) from V, 1% (1%) from VI, 18% (7%) from foreign countries, and 0% (1%) from geographically unknown sources. Both nuclear and cytoplasmic germplasm from Eco-regions I, II, and III, and foreign countries accounted for most of the ancestry of the released cultivars. In each of the eco-regions, with the exception of region VI, but especially in region I, the local nuclear and cytoplasmic germplasm was dominant in the released cultivars. Exotic germplasm accounted for an increasing portion of the nuclear and cytoplasmic germplasm, especially in Ecoregions I and II. The genetic base of the released cultivars is relatively narrow but has been gradually broadened, especially in Eco-regions I and II; and the average number of ancestors per cultivar released between 1996 and 2005 in various eco-regions was approximately double the period between 1986 and 1995. Seventy-eight ancestors accounted for 12% of the total ancestors but explained that 64% of the nuclear contribution and 70% of the cytoplasmic contribution to the 1300 released cultivars. For broadening the genetic base of future cultivars, the utilization of germplasm from outside regions is emphasized.     

The use of computer vision technologies in aquaculture – A review

Computer vision technology is a sophisticated inspection technology that is in common use in various industries. However, it is not as widely used in aquaculture. Application of computer vision technologies in aquaculture, the scope of the present review, is very challenging. The inspected subjects are sensitive, easily stressed and free to move in an environment in which lighting, visibility and stability are generally not controllable, and the sensors must operate underwater or in a wet environment. The review describes the state of the art and the evolution of computer vision in aquaculture, at all stages of production, from hatcheries to harvest. The review is organized according to inspection tasks that are common to almost all production systems: counting, size measurement and mass estimation, gender detection and quality inspection, species and stock identification, and monitoring of welfare and behavior. The objective of the review is to highlight areas of research and development in the field of computer vision which have made some progress, but have not matured into a useful tool. There are many potential applications for this technology in aquaculture which could be useful for improving product quality or production efficiency. There have been quite a few initiatives in this direction, and a tight collaboration between engineers, fish physiologists and ethologists could contribute to the search for, and development of solutions for the benefit of aquaculture.     

Efects of Tetcyclacis on Plant Growth and Development in Triticale cv. Lasko

ＥｆｆｅｃｔｓｏｆＴｅｔｃｙｃｌａｃｉｓｏｎＰｌａｎｔＧｒｏｗｔｈａｎｄＤｅｖｅｌｏｐｍｅｎｔｉｎＴｒｉｔｉｃａｌｅｃｖ．ＬａｓｋｏＪｉＳｈａｎｇｎｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＡｇｒｏｎｏｍｙｏｆＮｏｒｔｈｅａｓｔＡｇｒｉｃｕｌｔｕｒａｌＵｎｉｖ...     

Effects of Tetcyclacis on Plant Growth and Development in Triticale cv.Lasko

Experiments with tecyclacis applied as a seed-dressing carried out with triticale cv.Lasko in pots in the glasshouse and in hand-sown plots in the field.The sesults showed that tetcyclacis significantly delayed seedling emergence and inhibited the elongating growth in plant seedling stage,but not affected the growth and development of the adult plant during the late stage of stem extension and the stage of grain expansionl.No significant difference was found in fertile stem number,grain quality and yield between the treated plants with tetcyclacis and control.     

Adaptation of Drosophila species to climate change——A literature review since 2003

Global climate warming has been exerting impacts on agricultural pests. Pests also take some strategies to adapt to climate change. Understanding such adaptation could benefit more accurate predictions and integrated management of pest. However, adaptation to climate change has not been widely investigated in agricultural pests but has been well documented in model species, Drosophila, and reviewed by Hoffmann before 2003. To provide recent progress and references for agricultural entomologists who interested in thermal biology, here we have reviewed literatures since 2003 about adaptation to temperature changes under climate change. We mainly summarized thermal adaptation of Drosophila (especially to high temperatures) from three aspects, behaviors, plastic responses and micro-evolution and discussed how Drosophila increases their heat tolerance through these three mechanisms. Finally, we summarized the measures of thermotolerance and concluded the main progress in recent decade about the behavioral thermoregulation, mortality risks driven by limited evolutionary and plastic response under climate change, geographic distribution based on basal rather than plastic thermotolerance. We propose future work focus on better understanding adaptation of organisms including agricultural pests to climate change.     

A rapid multiplication system for ‘Candidatus Liberibacter asiaticus’ through regeneration of axillary buds in vitro

‘Candidatus Liberibacter asiaticus (CLas)’, which causes citrus Huanglongbing (HLB) disease, has not been successfully cultured in vitro to date. Here, a rapid multiplication system for CLas was established through in vitro regeneration of axillary buds from CLas-infected ‘Changyecheng’ sweet orange (Citrus sinensis Osbeck). Stem segments with a single axillary bud were cultured in vitro to allow CLas to multiply in the regenerating axillary buds. A high CLas titer was detected in the regenerated shoots on an optimized medium at 30 days after germination (DAG). This titer was 28.2-fold higher than in the midribs from CLas-infected trees growing in the greenhouse. To minimize contamination during in vitro regeneration, CLas-infected axillary buds were micrografted onto seedlings of ‘Changyecheng’ sweet orange and cultured in a liquid medium. In this culture, the titers of CLas in regenerated shoots rapidly increased from 7.5×10⁴ to 1.4×10⁸ cells μg^–1 of citrus DNA during the first 40 DAG. The percentages of shoots with >1×10⁸ CLas cells μg^–1 DNA were 30 and 40% at 30 and 40 DAG, respectively. Direct tissue blot immunoassay (DTBIA) indicated that the distribution of CLas was much more uniform in regenerated plantlets than in CLas-infected trees growing in the greenhouse. The disease symptoms in the plantlets were die-back, stunted growth, leaf necrosis/yellowing, and defoliation. The death rate of the plantlets was 82.0% at 60 DAG. Our results show that CLas can effectively multiply in citrus plantlests in vitro. This method will be useful for studying plant-HLB interactions and for rapid screening of therapeutic compounds against CLas in citrus.     

Plant Diversity and Vegetation Structure in Encroached and Non-encroached Areas of Borana Rangelands： The Case of Hallona and Medhacho Pastoralist Associations

The Borana rangelands are important areas of cattle production in Ethiopia. However, these rangelands are threatened by the increasing changes in the natural vegetation from grass and forbs dominated into unpalatable bushy woody vegetation resulting in the loss of some of the highly desirable grass species. This study was conducted to assess the impacts of bush encroachment on the biodiversity, structure and cover of the native vegetation in bush encroached and non-encroached sites. Vegetation data were collected from both sites by laying quadrate plots along transects using a systematic sampling method. According to the results, higher number of species was recorded in the non-encroached sites than that in the encroached sites. The diversity indices for the non-encroached and the encroached sites were 3.16 and 2.67, respectively. The abundance and cover analysis indicated that there was high density and cover of herbaceous species in the non-encroached site. There was a significantly higher density of woody species cover in the encroached site. Generally, the bush encroachment in the Borana rangelands has hampered the diversity of the native vegetation, particularly the grasses and forbs and reduced the ground cover, exposing large parts of the rangelands for soil erosion and other degradation process.     

Technical and environmental efficiency of hog production in China—A stochastic frontier production function analysis

This article analyses the technical and environmental efficiency of hog production in China using data from the China Agricultural Product Cost-Benefit Compilation(NDRC 2005–2013) and the First National Census of Pollution: Manual of Discharge Coefficient of Livestock and Poultry Industry(IEDA and NIES 2009). The empirical results show a great variation in environmental efficiency, ranging from 0.344 to 0.973 with a mean value of 0.672 that declines over time. Southwest China is found to be the most environmentally efficient region, while the Northeast and the Northwest are the least efficient. Another finding is that technical and environmental efficiencies are highly correlated in hog production; the most environmentally efficient regions are usually found to have high technical efficiency, and vice versa. In addition, we computed the output elasticities with respect to each factor input. The results show that feed is the most efficient input, with an output elasticity of approximately 0.551, which is much higher than the elasticity of the nitrogen surplus, other capital or labour. The output elasticity with respect to the nitrogen surplus is 0.287 on average. Finally, the scale elasticity in hog production is slightly higher than 1.     

Measurement of Grain Production Efficiency in Main Grain-producing Areas and Analysis of Inter-provincial Differences——A Study Based on Super-SBM Model and Malmquist Index

China’s food security mainly depends on the core areas of food production.Under the dual constraints of resource scarcity and environmental degradation,improving the grain production efficiency of the main grain-producing areas has become the fundamental way to strengthen the grain production capacity and improve the national food security capability,and to improve the efficiency of grain production in major grain-producing areas requires empirical support.This paper used the Super SBM model and...     

Over-Expression of Tomato GDP-Mannose Pyrophosphorylase （GMPase） in Potato Increases Ascorbate Content and Delays Plant Senescence

GDP-D-mannose pyrophosphorylase (GMPase) catalyses the synthesis of GDP-D-mannose and represents the first committed step in the synthesis of ascorbate. In the present study, the GMPase gene of tomato was introduced into potato by Agrobacterium-mediated transformation. Two transgenic lines with higher GMPase expression were selected using qPCR and protein blot analyses. The results showed that the content of L-ascorbic acid (AsA) and the ratio of AsA/DHA (dehydroascorbate) significantly increased in both leaves and tubers of transgenic potato plants. Both pigment content and photosynthetic rate were much higher in transgenic plants than in wild-type plants. Transgenic plants showed a distinguishable change in phenotype from the wild-type plants. Furthermore, transgenic plants showed delayed senescence.     

Deletion of TTTTA in 5′UTR of goat MSTN gene and its distribution in different population groups and genetic effect on bodyweight at different ages

A total of 436 goat samples from twenty-six populations were scanned for single nucleotide polymorphisms (SNPs) in 5′UTR of goat MSTN gene using sequencing and the polymerase chain reaction technique combined with restriction enzyme fragment length polymorphism (PCR-RFLP). The deletion of TTTTA found in 5′UTR of goat MSTN gene was conserved in different species and might be a unique mutation in goats. The Foreign Group and the Boer Goat backcrossed offspring had the highest and smallest genetic diversity of this mutation respectively, and also with the smallest and highest heterozygosity deficiency respectively. The genetic diversity of this mutation for the South Group of Chinese indigenous goat breeds was higher than that of the North Group, and the South Group had the smaller heterozygosity deficiency than the North Group. The estimated marginal means based on the modified population marginal mean and pairwise comparison between significant pairs showed that there was a trend that genotype AA had a significant effect on body weight and size from birth to four-month old (P<0.05 or P<0.01). It could be inferred that the deletion of TTTTA in 5′UTR of goat MSTN gene had a significant effect on body weight and size.