breeding

摘要： The aim of this study was to evaluate the maintenance of spermatozoa motility over 72 h by two commercial semen extenders used to centrifuge semen before re-suspending the sperm pellet in INRA 96^(■).Centrifuged and re-suspended semen samples were evaluated for percent motility using four commercial Standard bred stallions collected three times each during the spring and summer breeding season.Next Generation Dr.Kenney’s^(■)without antibiotic or INRA 96^(■)semen extenders were used to dilute semen samples in a 1:1 ratio prior to centrifugation at 750×g for 10 min.After decanting the supernatant,the resulting sperm pellets were then re-suspended and extended with INRA 96^(■)to a final concentration of 50 million total cells per millimeter and stored in Equine Express II stallion semen shipping containers.Percent progressive motility was recorded at time points 0,24,48,and 72 h.Analysis of variance between stallions,time,and extender type found that there was no significant difference in percent motility at each of the time points between the two extenders(p=0.87)used for centrifugation.Differences in percent motility over time and between stallions were found(p<0.001).The findings suggest that the use of Next Generation Dr.Kenney’s^(■)semen extender during centrifugation and then re-suspending the sperm pellet in INRA 96^(■)may be more cost effective than using INRA 96^(■)for both centrifugation and re-suspension of the sperm pellet.This is due to the fact that the less expensive Next Generation Dr.Kenney’s^(■)supernatant is decanted and discarded after the centrifugation step,instead of the much more expensive INRA 96^(■),yet does not affect the quality of semen preservation and motility over time.

摘要： Arbutus unedo L.(strawberry tree,Ericaceae)is a woody species with a circum-Mediterranean distribu-tion.It has considerable ecological relevance in southern European forests due to its resilience to abiotic and biotic stressors.Its edible red berries are used in the production of traditional products,including an expensive spirit.Several compounds extracted from the species have bioactive prop-erties used by the cosmetic and pharmaceutical industries.The strawberry tree has gone from a neglected species to become a highly valuable crop with large cultivated areas in southern European and North African countries.Due to an increasing demand from farmers for plants with improved features,researchers have been trying to improve this spe-cies through conventional and biotechnological tools,focus-ing mainly on population analysis using molecular markers,in vitro cloning,tolerance to biotic and abiotic stresses,and intraspecific crosses to obtain genotypes with new char-acteristics.The objective of this review is to gather and update information about the species and make it available to researchers and stakeholders.Future research areas that are considered a priority for this species are highlighted.

摘要： SCOPE Rice Science is an international peer-reviewed journal sponsored by China National Rice Research Institute and hosting by Elsevier B V.It publishes original research papers,review articles,technique methods as well as letters on rice science in English language.Some of the topics that may be included in each issue are:breeding and genetics,biotechnology,germplasm resources,agronomy,pest management,soil and fertilizer management and cereal chemistry.The full texts of Rice Science are available online at http://www.ricescience.org or http://www.sciencedirect.com/journal/rice-science.

摘要： [Objectives]To establish a breeding system for pre-elite seed potatoes.[Methods]Shoot-tip seedlings were cultured with different medium,and then transplanted in different substrates.They were sprayed with nutrient solutions of different formulas.Potato minitubers were induced.[Results]The medium of MS+2.0 mg/L 6-BA,1.0 mg/L NAA+3%sugar was preferable for potato shoot tip culture.After virus detection,the virus-free potato seedlings were propagated.The medium composed of vermiculite,peat and perlite(1∶3∶1)was recommended for transplanting potato tissue culture seedlings in greenhouse.The three-dimensional spray method was used to produce pre-elite seed potatoes.The full-amount MS nutrient solution could increase the tuber number per plant to 55.Induction of minitubers is a better breeding technology for pre-elite seed potatoes.The optimal medium screened for induction of potato minitubers was MS+(5-7)mg/L 6-BA,with a dark culture duration of about 20 d.[Conclusions]The breeding technology established is suitable for the two-season cultivation areas in Zaozhuang.

摘要： Anaerobic germination and emergence from deeper soil depth are two important traits for breeding rice suitable for direct seeded conditions.In order to evaluate genetic variation for these traits,a total of 300 Oryza nivara accessions were evaluated along with checks,of which,159 accessions germinated under anaerobic conditions indicating presence of immense variability in O.nivara.Of 159 accessions,69 germinated in submerged conditions and 90 germinated after removing water with availability of aerobic conditions,indicating two different mechanisms operating in O.nivara.Similarly,out of 300 O.nivara accessions,218 germinated from 6 cm and 95 germinated from 8 cm soil depth.The accessions that germinated from deeper soil depth had longer mesocotyl and coleoptile lengths.

摘要： Drought is one of the important factors limiting rice production,and the application of new water-saving rice varieties is urgently needed in rice production.Wanliangyou 1008 bred by Institute of Rice Research,Anhui Academy of Agricultural Sciences is a new two line hybrid rice variety with some good traits,including high drought resistance,high yield and good disease resistance.Wanlingyou 1008 was obtained by crossing drought-resistant high-quality restorer line DJ1008 and disease-resistant two-line sterile line Wan 25S.In this paper,the breeding process,characteristics and seed production technology of the variety were described in detail.

摘要： Kernel size, one of the traits that determine wheat yield, is controlled by multiple quantitative trait loci.Polish wheat(Triticum polonicum) has elongated and plump kernel and is a valuable material for breeding high-yielding wheat cultivars. However, genes or loci determining kernel length(KL) in Polish wheat are unknown. We identified and validated a major KL gene, KL-PW, at the P1 locus in Polish wheat. KL-PW is VRT-A2, which encodes a MIKC-type MADS-box protein(MADS55). An insertion/deletion mutation in intron 1 of VRT-A2;led to an alternatively spliced transcript, VRT-A2;. Quantitative PCR analysis showed that VRT-A2;was more highly expressed in developing seeds than was VRT-A2 Ailanmai.Brassinosteroid(BR) sensitivity experiment and the expression of BR-related genes indicated that VRTA2;functions as a positive regulator of BR responses. VRT-A2;significantly increased KL of wheat.These findings not only reveal the molecular basis of KL-PW in controlling KL, but also provide a valuable genetic resource for increasing kernel size in wheat.

摘要： This paper introduced the breeding process,characteristics,yield performance,disease resistance,quality characters,and suitable production areas of the new early-maturing oil sunflower variety"Xin Kui No.27",and summarized high-yield cultivation techniques based on large-area continuous cultivation demonstration to serve agricultural production.

摘要： Yujingyou 50 is a new high-quality late indica hybrid rice combination selected by Institute of Grain and Oil Crops,Nanchang Academy of Agricultural Sciences and Hunan Zhonglang seed Industry Co.,Ltd.The combination matured 3 d earlier than Tianyouzhan.It has the characteristics of moderate plant type,broad and long flag leaves,general tillering ability,colorless palea tips,large panicles with many grains,high seed setting rate,average 1000-grain weight,good color change at maturity,and rice quality reaching grade 2 of ministry standard.It was approved by the Jiangxi Provincial Crop Variety Approval Committee on March 18,2021.This paper introduced the breeding process,characteristics,cultivation techniques and key points of seed production of this variety.

摘要： Cowpea [Vigna unguiculata (L.) Walp.] is an important grain legume mainly grown in tropical and subtropical regions for vegetables, grains, and fodder. The crop is grown predominantly in the dry savannahs to the Sahel in the fringes of the Sahara Desert where the annual rainfall is around 300 mm or less. Cowpea provides shelter as a cover crop and improves soil fertility by fixing atmospheric nitrogen. Its grain is preferred for high levels of protein, energy, micro-and macronutrients. Cowpea belongs to the family Fabaceae and sub-family Faboidea, and it is a self-pollinating crop with low and narrow genetic diversity, making it susceptible to various environmental factors. Various research projects have been established on cowpea, and as a result, various cowpea germplasm is stored at Africa International Institute of Tropical Agriculture (IITA)—Nigeria, the USDA repository in Griffin, GA (USA), the University of California, Riverside, CA (USA), and at the National Bureau of Plant Genetic Resources (NBPGR) in New Delhi, India. Despite the available germplasms, cowpea productivity remains very low in many countries due to a wide array of abiotic and biotic stresses and socio-economic constraints. This review summarizes some aspects of cowpea, including origin and history, challenges, economic importance, and constraints to production, providing possible useful information for cowpea researchers, agronomists, and producers in SSA.