Key Techniques of an Ecological Pattern“Planting Rice in One Season and Breeding Red Swamp Crawfish in Three Seasons” for Green Production in Lixiahe Region of Jiangsu Province

Three big field projects, independent irrigation and drainage facilities, and a blocking net, which are auxiliary projects of a green planting and breeding pattern composed of rice and red swamp crawfish （Procambarus clarkii）, spatial and temporal coupling technology of ＂planting rice in one season and breeding red swamp crawfish in three seasons＂, green fertilization technology, green prevention and control technology, control technology of water level, and throwing technology of bait in Lixiahe region of Jiangsu Province were introduced successively, which can provide technical support for the development of ecological planting and breeding patterns and realization of green production in paddy fields.

Breeding against mycorrhizal symbiosis:Modern cotton (Gossypium hirsutum L.) varieties perform more poorly than older varieties except at very high phosphorus supply levels

Cotton (Gossypium hirsutum L.) is an importantfiber cash crop,but its root traits related to phosphorus (P) acquisition,including mycorrhizal root traits,are poorly understood.Eight cotton varieties bred in northwestern China that were released between 1950 and 2013 were grown in pots with or without one arbuscular mycorrhizal fungal (AMF) species(Funneliformis mosseae) at three P supply levels (0,50 and 300 mg P as KH_(2)PO_(4)kg^(-1)).Eleven root traits were measured and calculated after 7 wk of growth.The more recent accessions had smaller root diameters,acquired less P and produced less biomass,indicating an (inadvertent) varietal selection for thinner roots that provided less cortical space for AMF,which then increased the need for a high P fertilizer level.At the two lower P levels,the mycorrhizal plants acquired more P and produced more biomass than non-mycorrhizal plants (3.2 vs.0.9 mg P per plant;1.8 vs.0.9 g biomass per plant at P_(0);14.5 vs.1.7 mg P per plant;and 4.7 vs.1.6 g biomass per plant at P_(50)).At the highest P level,the mycorrhizal plants acquired more P than non-mycorrhizal plants (18.8 vs.13.4 mg per P plant),but there was no difference in biomass (6.2 vs.6.3 g per plant).At the intermediate P level,root diameter was significantly positively correlated with shoot biomass,P concentration and the P content of mycorrhizal plants.The results of our study support the importance of the outsourcing model of P acquisition in the root economics space framework.Inadvertent varietal selection in the last decades,resulting in thinner roots and a lower benefit from AMF,has led to a lower productivity of cotton varieties at moderate P supply (i.e.,when mycorrhizal,the average biomass of older varieties 5.0 g per plant vs.biomass of newer varieties 4.4 g per plant),indicating the need to rethink cotton breeding efforts in order to achieve high yields without very high P input.One feasible way to solve the problem of inadvertent varietal selection for cotton is to be aware of the trade-offs between the root do-it-yourself strategy and the outsourcing towards AMF strategy,and to consider both morphological and mycorrhizal root traits when breeding cotton varieties.

Participatory Plant Breeding and Selection Impact on Adoption of Improved Sweetpotato Varieties in Uganda

This study analyzed the impact of participatory plant breeding （PPB） and participatory variety selection （PVS） on the adoption of improved sweetpotato varieties （ISPV） in central Uganda. The study quantitatively assessed how the two approaches influence farmers＇ uptake of the improved sweetpotato varieties and also determined other factors influencing this adoption. This was done by estimating a robust standard errors logit model. Both PPB and PVS positively and significantly influenced the likelihood of adoption of improved sweetpotato varieties at 5% and 10% levels, respectively. Other variables that positively influenced the adoption are extension services, training in sweetpotato production, farming experience, and off-farm income of the household. Farmers who participated in the plant breeding and variety selection processes were 37 and 6.7 times more likely to adopt the improved sweetpotato varieties than those who had not, respectively. Farmers who were trained specifically in sweetpotato production were 8.8 times more likely to adopt the improved varieties than those who had not received this type of training.

Pre-Breeding Genetic Diversity Assessment of Tomato(Solanum lycopersicum L.)Cultivars Based on Molecular,Morphological and Physicochemical Parameters

Appropriate knowledge of the parental cultivars is a pre-requisite for a successful breeding program.This study characterized fruit yield,quality attributes,and molecular variations of ten tomato cultivars during three consecutive generations under greenhouse conditions.Peto 86,Castle Rock,and Red Star cultivars showed the highest fruit yield(kg/plant),total phenolic compounds(TPC),and sap acidity.Principal component analysis categorized the evaluated fruit yield into three groups based on their quality attributes.A robust positive correlation appeared among traits inside each group.A positive correlation was likewise noticed between the first and the second groups.However,a negative correlation was detected between the first,the second and the third group.Molecular profiling,using seven inter-simple sequence repeat(ISSR)primers,produced 60 loci,including 49 polymorphic loci.The molecular analysis also pinpointed the highest genetic similarity(0.92)between P73 and Moneymaker,while the lowest genetic similarity(0.46)was observed between Castle Rock and Moneymaker.The cultivars P73 and Moneymaker showed the lowest genetic distance(2.24),while the highest genetic distance(5.92)was observed between Super Marmand and Peto86,on the one hand,and between Castle Rock and Moneymaker,on the other hand.The chemical analysis of fruit sap indicated the highest levels of TPC,total flavonoids,anthocyanin,ascorbic acid and total soluble solids in Peto 86 and Castle Rock cultivars.Phylogeny analysis of tomato cultivars based on morphological and molecular attributes indicated four distinct clades.Peto 86,Castle Rock,and Red star cultivars can be recommended for the tomato hybridization breeding programs in the future,with other tomato cultivars as potentially high-yielding parents.

Enemies atpeace:Recentprogressin Agrobacterium-mediated cereal transformation

Agrobacterium tumefaciens mediated plant transformation is a versatile tool for plant genetic engineering following its discovery nearly half a century ago.Numerous modifications were made in its application to increase efficiency,especially in the recalcitrant major cereals plants.Recent breakthroughs in transformation efficiency continue its role as a mainstream technique in CRISPR/Cas-based genome editing and gene stacking.These modifications led to higher transformation frequency and lower but more stable transgene copies with the capability to revolutionize modern agriculture.In this review,we provide a brief overview of the history of Agrobacterium-mediated plant transformation and focus on the most recent progress to improve the system in both the Agrobacterium and the host recipient.A promising future for transformation in biotechnology and agriculture is predicted.

Ethical and legal implications of gene editing in plant breeding:a systematic literature review

Biotechnology policies and regulations must be revised and updated to reflect the most recent advances in plantbreeding technology. New Plant Breeding Techniques(NPBT) such as gene editing have been applied to address the myriad of challenges in plant breeding, while the use of NPBT as emerging biotechnological tools raises legal and ethical concerns. This study aims to highlight how gene editing is operationalized in the existing literature and examine the critical issues of ethical and legal issues of gene editing for plant breeding. We carried out a systematic literature review(SLR) to provide the current states of ethical and legal discourses surrounding this topic. We also identified critical research priority areas and policy gaps that must be addressed when designing the future governance of gene editing in plant breeding.

Applications of cold atmospheric plasmas(CAPs)in agriculture:a brief review and the novel development of a radio-frequency CAP jet generator for plant mutation

Cold atmospheric plasmas(CAPs)have shown great applicability in agriculture.Many kinds of CAP sources have been studied in agricultural applications to promote plant growth and cure plant diseases.We briefly review the state-of-the-art stimulating effects of atmospheric-pressure dielectricbarrier-discharge(AP-DBD)plasmas,after the direct or indirect treatment of plants for growth promotion and disease control.We then discuss the special demands on the characteristics of the CAP sources for their applications in plant mutation breeding.An atmospheric and room temperature plasma(ARTP)jet generator with a large plasma irradiation area,a high enough concentration of chemically reactive species and a low gas temperature is designed for direct plant mutagenesis.Experimental measurements of the electrical,thermal and optical features of the ARTP generator are conducted.Then,an ARTP-P(ARTP for plant mutagenesis)mutation breeding machine is developed,and a typical case of plant mutation breeding by the ARTP-P mutation machine is presented using Coreopsis tinctoria Nutt.seeds.Physical and agricultural experiments show that the newly-developed ARTP-P mutation breeding machine with a large irradiation area can generate uniform CAP jets with high concentrations of chemically reactive species and mild gas temperatures,and have signiflcant mutagenesis effects on the Coreopsis tinctoria Nutt.seeds.The ARTP-P mutation breeding machine may provide a platform for systematic studies on mutation mechanisms and results for various plant seeds under different operating conditions in future research.

Evaluation of cotton germplasm for morphological and biochemical host plant UPdates resistance traits against sucking insect pests complex

Background:Sucking insect pests cause severe damage to cotton crop production.The development of insect resistant cotton cultivars is one of the most effective measures in curtailing the yield losses.Considering the role of morphological and biochemical host plant resista nee(HPR)traits in plant defense,12 cotton genotypes/varieties were evaluated for leaf area,leaf glanding,total soluble sugars,total soluble proteins,total phenolics,tannin and total flavonoids against fluctuating populations of whitefly,thrips and jassid under field conditions.Results:The population of these insects fluctuated during the growing seas on and remained above threshold level(whitefly>5,thrips>(8-10)f or jassid>1 per leaf)during late June and early July.Strong and negative association of whitefly(r=-0.825)and jassid(r=-0.929)with seed cotton yield was observed.Mean population of insects were the highest in Glandless-1 followed by NIA-82 and NIA-M30.NIAB-Kiran followed by NI AB-878 and Sadori were the most resistant,with the mean population of 1.41,1.60,1.66(whitefly);2.24,232,2.53(thrips)and 037,0.31,036(jassid),respectively.The resistant variety NIAB-Kiran showed less soluble sugars(8.54 mg.g^(-1)),soluble proteins(27.11 mg.g^(-1))and more phenolic(36.56 mg.g^(-1))and flavonoids(13.10mg.g^(-1))as compared with the susceptible check Glandless-1.Moreover,all insect populations were positively correlated with total soluble sugars and proteins.Whitefly populations exhibited negative response to leaf gossypol glands,total phenolics,tannins and flavonoids.The thrips and jassid populations had a significant and negative correlation with these four biochemical HPR traits.Conclusion:The ide ntified resistant resources and HPR traits can be deployed against sucking in sect pests'complex in future breeding programs of developing insect resistant cotton varieties.

Advances in Transgenic Vegetable and Fruit Breeding

Vegetables and fruits are grown worldwide and play an important role in human diets because they provide vitamins, minerals, dietary fiber, and phytochemicals. Vegetables and fruits are also associated with improvement of gastrointestinal health, good vision, and reduced risk of heart disease, stroke, chronic diseases such as diabetes, and some forms of cancer. Vegetable and fruit production suffers from many biotic stresses caused by pathogens, pests, and weeds and requires high amounts of plant protection products per hectare. United States vegetables farmers are benefiting from growing transgenic squash cultivars resistant to Zucchini yellow mosaic virus, Watermelon mosaic virus, and Cucumber mosaic virus, which were deregulated and commercialized since 1996. Bt-sweet corn has also proven effective for control of some lepidopteran species and continues to be accepted in the fresh market in the USA, and Bt-fresh-market sweet corn hybrids are released almost every year. Likewise, transgenic Bt-eggplant bred to reduce pesticide use is now grown by farmers in Bangladesh. Transgenic papaya cultivars carrying the coat-protein gene provide effective protection against Papaya ring spot virus elsewhere. The transgenic “Honey Sweet” plum cultivar provides an interesting germplasm source for Plum pox virus control. Enhanced host plant resistance to Xanthomonas campestris pv. musacearum, which causes the devastating banana Xanthomonas wilt in the Great Lakes Region of Africa, was achieved by plant genetic engineering. There are other vegetable and fruit crops in the pipeline that have been genetically modified to enhance their host plant resistance to insects and plant pathogens, to show herbicide tolerance, and to improve features such as slow ripening that extends the shelf-life of the produce. Consumers could benefit further from eating more nutritious transgenic vegetables and fruits. Transgenic plant breeding therefore provides genetically enhanced seed embedded technology that contributes to integrated pest management in horticulture by reducing pesticide sprays as well as improving food safety by minimizing pesticide residues. Furthermore, herbicide-tolerant transgenic crops can help reducing plough in fields, thereby saving fuel because of less tractor use, which also protects the structure of the soil by reducing its erosion. Transgenic vegetable and fruit crops could make important contributions to sustainable vegetable production and for more nutritious and healthy food. Countries vary, however, in their market standards of acceptance of transgenic crops. Biotechnology products will be successful if clear advantages and safety are demonstrated to both growers and consumers.

Increasing yield potential of hybrid rice through molecular breedingIncreasing yield potential of hybrid rice through molecular breeding

Rice is the staple food for more than half of the world population. The utilization of the wild abortive cytoplasmic male sterility （CMS） in 1970s has significantly raised rice yield potential. But the world＇s annual rice production will have to increase 70 percent over the next 30 years, to keep up with the demends of the growing population.

Cultivating potential:Harnessing plant stem cells for agricultural crop improvement

Meristems are stem cell-containing structures that produce all plant organs and are therefore important targets for crop improvement.Developmental regulators control the balance and rate of cell divisions within the meristem.Altering these regulators impacts meristem architecture and,as a consequence,plant form.In this review,we discuss genes involved in regulating the shoot apical meristem,inflorescence meristem,axillary meristem,root apical meristem,and vascular cambium in plants.We highlight several examples showing how crop breeders have manipulated developmental regulators to modify meristem growth and alter crop traits such as inflorescence size and branching patterns.Plant transformation techniques are another innovation related to plant meristem research because they make crop genome engineering possible.We discuss recent advances on plant transformation made possible by studying genes controlling meristem development.Finally,we conclude with discussions about how meristem research can contribute to crop improvement in the coming decades.

Constitutive basis of root system architecture:uncovering a promising trait for breeding nutrient-and drought-resilient crops

Root system architecture(RSA)plays a pivotal role in efficient uptake of essential nutrients,such as phosphorous(P),nitrogen(N),and water In soils with heterogeneous nutrient distribution,root plasticity can optimize acquisition and plant growth.Here,we present evidence that a constitutive RSA can confer benefits for sorghum grown under both sufficient and limiting growth conditions.Our studies,using P efficient SC103 and inefficient BTx635 sorghum cultivars,identified significant differences in root traits,with SC103 developing a larger root system with more and longer lateral roots,and enhanced shoot biomass,under both nutrient sufficient and deficient conditions.In addition to this constitutive attribute,under P deficiency,both cultivars exhibited an initial increase in lateral root development;however,SC103 still maintained the larger root biomass.Although N deficiency and drought stress inhibited both root and shoot growth,for both sorghum cultivars,SC103 again maintained the better performance.These findings reveal that SC103,a P efficient sorghum cultivar,also exhibited enhanced growth performance under N deficiency and drought.Our results provide evidence that this constitutive nature of RSA can provide an avenue for breeding nutrient-and drought-resilient crops.

Fifty Years of Botanical Gardens in China

The development, distribution and features of one hundred and forty botanical gardens (BGs) in China are reported and their functions on research, conservation, display and utilization of biodiversity are summarized in this paper. The contributions to the social and economic development in the early stage of Chinese BGs with the researches of economic plant (tobacco), medicinal plant (yam) and wild fruit tree resources are evaluated. The theoretical and applied achievements in recent years in seed science, plant conservation, economic plant introduction, acclimatization and breeding are also described. A general scope of living plant collections in Chinese BGs is presented and the outstanding ones, including Magnoliaceae, Zingiberaceae, Cycadaceae, medicinal plants, Actinidia and Rhododendron are particularly mentioned. With special reference to Chinese penjing art garden and silicified wood garden, the development of scientific popularization and tourism in BGs is reviewed.

A New Model of Recycling Agricultural Production

[Objective] The aim was to research production model of recycling agricul- ture. [Method] The production model of recycling agriculture integrating planting and breeding was explored on basis of pig raising, and maize and peanut planting, with consideration of existing problems of planting and breeding integration in China. [Result] Ecological and economic benefits of pig farms and planting bases increased significantly, and all indices improved in different degrees. [Conclusion] The research provides valuable references for pig raising in China.

Progress and future development of hybrid rapeseed in China

The hybrid growth of rapeseed now has reached to 4.7×106hm2,accounting for 70 % of total rapeseed growth area in China. Over the last 40 years,the researches and utilizations of hybrid rapeseed in China have significantly contributed to the development of rapeseed industry in China. The production of hybrid rapeseed mainly utilizes cytoplasmic male sterility(CMS),combined at the same time with nuclear male sterility and other pollinating-control systems in China. The hybrid rapeseed studies in China are also characterized by the improvement of quality and oil content in hybrid breeding. Future studies to enhance the heterosis of rapeseed will be focused on several important issues,including the combination of heterosis and ideotype breeding,further increase of oil content in hybrids,utilization of sub-genomic heterosis and resistance improvement. The paper will discuss the following perspectives in hybrid rapeseed studies:relationships among heterosis,quality and disease traits,solutions for excessive source and pool in hybrids compared with open-pollinated cultivars,and the importance of increasing harvest index of hybrids to achieve a better yield in hybrids.

Gene editing: an instrument for practical application of gene biology to plant breeding

Plant breeding is well recognized as one of the most important means to meet food security challenges caused by the ever-increasing world population. During the past three decades, plant breeding has been empowered by both new knowledge on trait development and regulation(e.g., functional genomics) and new technologies(e.g., biotechnologies and phenomics). Gene editing, particularly by clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas) and its variants, has become a powerful technology in plant research and may become a game-changer in plant breeding. Traits are conferred by coding and non-coding genes. From this perspective, we propose different editing strategies for these two types of genes. The activity of an encoded enzyme and its quantity are regulated at transcriptional and post-transcriptional, as well as translational and post-translational, levels. Different strategies are proposed to intervene to generate gene functional variations and consequently phenotype changes. For non-coding genes, trait modification could be achieved by regulating transcription of their own or target genes via gene editing. Also included is a scheme of protoplast editing to make gene editing more applicable in plant breeding. In summary, this review provides breeders with a host of options to translate gene biology into practical breeding strategies, i.e., to use gene editing as a mechanism to commercialize gene biology in plant breeding.

Application of stable isotope techniques to the study of soil salinization

In this paper,we reviewed the progress in the application of stable isotope techniques to the study of soil salinization.As a powerful technique,stable isotopes have been widely used in the studies of soil water evaporation,the dynamics of soil salinization and salt-tolerant plant breeding.The impact of single environmental factors on plant isotope composition has been the focus of previous studies.However,the impact of multiple environmental factors on plant isotope composition remains unclear and needs to be carefully studied.In order to gain insights into soil salinization and amelioration,especially soil salinization in arid and semiarid areas,it is essential to employ stable isotope techniques and combine them with other methods,such as located field observation and remote sensing technology.