Sweetpotato is an important crop that exhibits hexaploidy and high heterozygosity, which limits gene mining for important agronomic traits. Here, 314 sweetpotato germplasm resources were deeply resequenced, and 4 599 509 SNPs and 846 654 InDels were generated, among which 196 124 SNPs were nonsynonymous and 9690 InDels were frameshifted. Based on the Indels, genome-wide marker primers were designed, and 3219 of 40 366 primer pairs were selected to construct the core InDel marker set. The molecular ID of 104 sweetpotato samples verified the availability of these primers. The sweetpotato population structures were then assessed through multiple approaches using SNPs, and diverse approaches demonstrated that population stratification was not obvious for most Chinese germplasm resources. As many as 20 important agronomic traits were evaluated, and a genome-wide association study was conducted on these traits. A total of 19 high-confidence loci were detected in both models. These loci included several candidate genes, such as IbMYB1, IbZEP1, and IbYABBY1, which might be involved in anthocyanin metabolism, carotenoid metabolism, and leaf morphogenesis, respectively. Among them, IbZEP1 and IbYABBY1 were first reported in sweetpotato. The variants in the promoter and the expression levels of IbZEP1 were significantly correlated with flesh color (orange or not orange) in sweetpotato. The expression levels of IbYABBY1 were also correlated with leaf shape. These results will assist in genetic and breeding studies in sweetpotato.

通过使用20％聚乙二醇(PEG)-6000模拟干旱环境验证光合参数对于甘薯抗旱评价的适用性,并优化甘薯抗旱评价方法.结果表明,通过丙二醛(MDA)含量和相对含水量(RWC)变化值鉴定了3个甘薯栽培种的耐旱性,24、72 h干旱胁迫下甘薯抗旱性表现一致,均为潮薯1号抗旱性最强,徐薯18居中,福薯7-6最弱.分别测量3、24 h干旱胁迫处理下净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和胞间CO2浓度(Ci)4个光合参数的变化值,24 h干旱胁迫下光合参数的变化与MDA含量和RWC变化一致.相关性分析结果表明,4个光合参数与MDA含量、RWC均有极显著相关性,其中Ci与MDA含量、RWC的相关系数均最大,证明了4个光合参数均可作为抗旱评价指标.对24 h干旱胁迫下4个光合参数的变化值进行主成分分析,第1主成分的特征值为3.90,累计贡献率达到97.39％,基于主成分分析方法利用光合参数建立了甘薯抗旱性综合评价指数模型.

为解决谷子生产中倒伏问题,本研究通过EMS诱导晋谷21,选育了优质矮秆突变体谷子品种.分析比较突变体谷子的光合特性、农艺性状、营养元素含量、产量和小米品质等指标.结果表明,经过EMS诱导的矮秆突变体谷子,单位面积的净光合速率较低,但叶片总面积较大;产量方面虽有降低,但小米品质较好;株高降低和茎粗增加,有利于解决谷子生产中的倒伏问题.

对2018-2020年通过农业农村部非主要农作物品种登记的15个菜用甘薯品种的基本信息、地上部性状、茎尖食味、产量和抗病性共5个方面主要特性进行分析.发现菜用甘薯品种登记存在的问题主要为品种登记信息填写不规范、部分品种信息严重缺失、抗病性品种较少、品种登记进展缓慢.对此,提出了加强菜用甘薯品种登记的措施建议:加强非主要农作物品种登记宣传力度,熟悉登记操作流程,提高育种者新品种登记意识;加强登记过程管理,规范登记信息填报;加强菜用甘薯抗病性育种工作,提高品种综合抗性;优化甘薯品种登记制度,防止假冒品种、侵权品种和同种异名重复登记等.

[目的]筛选感甘薯病毒病(SPVD)甘薯脱毒组培苗快繁最佳激素组合,为甘薯脱毒种苗在生产上的应用提供技术支撑.[方法]以徐薯22和阜徐薯20为试验材料,通过不同脱毒次数、病毒抑制剂、浓度激素(NAA/6-BA)组合、继代培养时间及炼苗等条件对茎尖分生组织培养,检测不同处理对SPVD的脱除率,测量组培苗株高,统计移栽成活率.[结果]甘薯褪绿矮化病毒(SPCSV)一次茎尖分生组织培养脱除率达100％,甘薯羽状斑驳病毒(SPFMV)二次茎尖分生组织培养脱除率达100％;病毒抑制剂宁南·嘧肽预处理SPFMV茎尖脱除率达100％;徐薯22组培苗快繁最佳激素组合为0.05 mg/L NAA、1.0 mg/L 6-BA,阜徐薯20组培苗快繁最佳激素组合为0.01 mg/L NAA、1.0 mg/L 6-BA;徐薯22和阜徐薯20炼苗处理在继代培养60 d时,最高成活率达86.67％和83.33％.[结论]二次茎尖分生组织培养可完全脱除SPVD,病毒抑制剂宁南·嘧肽预处理可提高SPFMV茎尖脱除率,组培苗快繁的最佳激素组合为0.01～0.05 mg/L NAA、1.0 mg/L 6-BA,炼苗可显著提高组培苗移栽成活率.

为丰富谷子种质资源,提高叶色黄化突变体谷子的生产潜力,对EMS诱变育种过程中发生的叶色黄化突变体谷子进行研究.以晋谷21号经EMS诱变后选育的叶色黄化突变体谷子作为材料,通过叶面喷施氮肥处理后,测定叶片中光合能力、光合色素、糖类化合物含量和成熟后农艺性状以及小米品质.结果表明,与对照相比,施氮后黄化谷子的净光合速率和气孔导度增加,叶绿素a和总叶绿素含量增加,茎粗、千粒质量和小米类胡萝卜素含量增加.合理施氮一段时间后,能改善和提高黄化谷子叶片的光合能力和生理代谢,增加黄化谷子的抗倒伏能力和谷子籽粒灌浆效率,优化种子质量和小米品质.

该研究基于TP-M13-SSR分子标记荧光毛细管检测技术,以中国已入库登记的99份甘薯品种为材料,利用SSR标记建立登记品种的“01”数据库,导入DPS软件计算不同品种之间的遗传距离,采用MEGA的邻接法进行聚类分析,并利用Structure混合模型对材料进行遗传结构分析,以探讨各品种的遗传构成以及品种间的亲缘关系,揭示中国甘薯登记品种在DNA水平的相似度,为甘薯品种鉴定、亲本选配和品种改良等提供参考.结果 显示:(1)28对引物共扩增出162条谱带,多态率为96.30％,每对引物平均获得5.57条多态性谱带.(2)构建了99份甘薯登记品种的遗传进化树,99份品种的遗传距离在0～0.464 6之间,平均遗传距离为0.307 7;在遗传距离为0.267 0处将99份品种分为3个类群,且同一生态薯区的品种或具有同一亲本的品种首先被聚在一起,但不同生态薯区的品种在各类群中相对分散分布.(3)品种间的遗传基础较窄,部分生态薯区的品种相似性较高;群体结构分析将材料分为3个亚群,与聚类分析分群结果基本一致,其中31份材料拥有混合来源,遗传背景较为复杂.