Large-grain traits are important in high-yield breeding of wheat. In order to identify the genetic characteristics of grain traits in the large-grain wheat, we used the large-grain type Luomai 76 as the male parent and the small-grain type L529 as the female parent to construct six pedigrees of four generation populations（P 1 ,P 2 ,F 1 ,F 2 ,B 1 and B 2 ）,and applied mixed major gene plus polygenes inheritance model to identify the genetic characteristics of grain traits based on SmartGrain. The results showed that the best genetic model for grain weight was MX2-ADI-ADI; The best genetic model for grain area and grain length were PG-ADI; The best genetic model for grain perimeter length was 2MG-ADI; The best genetic model for grain width was MX2-ADI-AD. Taken together, for the selection of large-grain character, materials with high grain weight should be adopted as the parents to construct F 2 （single cross） and B 2 （backcross with large-grain parents） selection population, identified in multiple environments. The large grain characters are suggested to be rigorously selected in the high generations.
In order to clarify the climatic conditions for the quality formation of winter wheat, we analyzed the climatic resource characteristics of winter wheat from heading to maturity and the characteristics of winter wheat quality with four gluten types（strong gluten, medium strong gluten, medium gluten and weak gluten）, and we identified the climatic conditions for the formation of wheat quality, using the data of 10 winter wheat quality indices and their corresponding climatic data from 2006 to 2015 in five major provinces（Hebei, Shandong, Henan, Anhui, Jiangsu） of China in this study. The results showed that the dominant climate factors of the same quality index of winter wheat with different gluten types were different, and the dominant climatic factors of different quality indices of the same type winter wheat were also different. On the whole, the main factors for quality formation of winter wheat were temperature and humidity. The quality of strong gluten winter wheat was mainly affected by the number of high-temperature days ≥32 ℃ and precipitation from heading to maturity, and the quality of strong gluten winter wheat was better under good temperature and heat conditions. The quality of medium and strong gluten winter wheat was mainly affected by the number of precipitation days and the daily temperature range, which had negative effects on quality（except for extensibility）. The quality of medium gluten winter wheat was mainly affected by the maximum temperature and the number of precipitation days. For weak gluten winter wheat, the quality got worse when there were the more days with the daily maximum temperature ≥32 ℃ or greater humidity.
小麦株高与植株倒伏密切相关,影响小麦产量.为挖掘小麦株高QTL位点和候选基因,从遗传和分子水平上解释株高分子机理,本研究将野生二粒小麦染色体臂置换系CASL7AS为母本,课题组自选株系浙农林12(简称ZNL12)为父本,杂交F1经过花培得到178个DH群体.通过4年2个种植点株高数据,利用55K SNP芯片构建高密度遗传图谱,对小麦株高性状进行QTL分析.该遗传连锁图谱包含3 655个SNP标记,长度为4 738.45 cM,标记间平均遗传距离为1.30 cM,覆盖了小麦21条染色体.其中,A、B、D染色体组分别含有标记1 466、1 492和697个.QTL分析共检测出53个QTL位点,分布于1A、3A、5A、7A、1B、3B、4B、5B、7B、2D、4D、6D和7D染色体上,可解释2.80％～38.50％表型变异.其中,稳定主效QTL有2个,分别为QPh.zafu.4B-1和QPh.zafu.4D-1,其贡献率分别为25.18％～38.50％和20.67％.经细胞生物学分析,基因型为(0,2)矮秆植株胚芽鞘的表皮细胞长度显著短于基因型为(2,0)的高秆植株,基因型为(0,0)、(2,2)中间型的植株胚芽鞘表皮细胞长度无显著差异,由此推测小麦株高的变异由细胞长度因素决定.QPh.za-fu.4B-1候选基因Rht-B1b基因编码区矮秆株系,第904核苷酸处发生碱基"C-T"的突变,形成终止密码子(CAG-TAG);而QPh.zafu.4D-1候选基因Rht-D1b基因编码区矮秆株系,第781核苷酸处碱基突变"G-T",编码氨基酸中缬氨酸变为天冬氨酸.结果为小麦株高候选基因的筛选和QTL定位提供了优异的遗传位点和候选基因,未来可用于小麦抗倒伏相关的分子标记辅助育种.
为探究陕西关中地区小麦HMW-GS亚基与品质性状间的关系,采用SDS-PAGE法对57份陕西关中地区小麦品种(系)HMW-GS亚基组成及相关品质性状进行了分析.结果表明,供试品种(系)中共检测出7种HMW-GS亚基类型和8种HMW-GS亚基组合;Glu-A1位点上有3种亚基类型,分别为1、2*和Null,以1亚基为主(78.95％);Glu-B1位点上检测到7+8(61.40％)与7+9(38.60％)两个类型;Glu-D1位点上检测到5+10(70.18％)和2+12(29.82％)两个类型.3个HMW-GS基因位点编码亚基共组成8种亚基组合,品质得分6～10分,其中1/7+8/5+10组合品质得分10分,出现频率最高.就HMW-GS不同位点对品质性状效应进行分析发现,Glu-D1位点对b*值、形成时间、稳定时间、弱化度和粉质质量指数的影响达到极显著水平(P＜0.01);对面团流变学特性的影响,Glu-D1＞Glu-B1.不同类型亚基对小麦品质的效应存在差异,7+8亚基对蛋白质含量、湿面筋含量和容重具有正效应,7+9和5+10亚基对形成时间和稳定时间的影响显著高于其他亚基(P＜0.05);携带1/7+8/5+10亚基组合小麦的蛋白质、湿面筋含量和容重最高;携带1/7+9/5+10亚基组合具有较高面粉L*值和面团流变学特性指标值.
穗发芽严重降低谷物的产量和品质,种子休眠与穗发芽高度相关.为了解中国青稞品种休眠特性及其主效休眠基因AlaAT和MKK3的单倍型分布,以143份地方品种和42份育成品种(系)为材料,分别种植在四川雅安、什邡和西藏拉萨,进行大田种子休眠性鉴定;选择休眠性极端材料,分别利用2对引物对含有目标休眠基因功能性SNP的片段进行扩增、测序,并用于Ala AT和MKK3基因特异性KASP标记开发与供试材料的单倍型分析.结果表明,3个种植点,地方品种的发芽指数(GI)均高于育成品种(系),但差异不显著;四川2个种植点间GI值差异不显著,但显著高于西藏种植点,说明青稞品种(系)普遍休眠性弱,高原气候条件显著促进种子休眠.KASP标记检测发现,AlaAT和MKK3的强优势单倍型均为弱休眠单倍型(频率＞80％),供试材料中有 4 种单倍型组合,分别为 AlaAT-ND+MKK3-ND、AlaAT-ND+MKK3-D、AlaAT-D+MKK3-ND和AlaAT-D+MKK3-D,频率分别为80.0％、12.4％、6.0％和1.6％,其GI值随强休眠单倍型数量增加而降低;3个环境下,含有组合AlaAT-D+MKK3-D的GI值最低,说明休眠基因具有加性效应,聚合优良单倍型的品种(系)具有稳定的休眠特性.青稞生产和育种应根据种植区域和用途选择与利用上述主效休眠基因单倍型.
