Abstract: Elite foxtail millet cultivars such as Yugu 1, Jingu 21, and so on, contribute significantly to the development of foxtail millet industry. To better understand the genetic basis of excellent traits and the value in use of foxtail millet, phenotypic identification and genetic variation analysis were performed on 12 major foxtail millet cultivars selected from different ecological regions in this study. The results showed that large variations in plant height, panicle length, panicle thickness, internode length, single panicle weight, growth period and yellow pigment content were observed among the 12 cultivars. PCR amplification was carried out for the 12 elite foxtail millet cultivars by using SSR markers. A total of 258 polymorphic loci were detected by 79 pairs of SSR primers, with an average of 3.265 8 per pair. The polymorphism information content (PIC) values of the SSR markers ranged from 0.141 1 to 0.711 6, with an average of 0.510 1. 50 pairs of SSR primers had the PIC>0.5, accounting for 63.3% of the total polymorphic primers. The genetic distance between the 12 foxtail millet cultivars varied from 0.140 2 to 0.801 1, with an average of 0.473 7. The genetic distance between Yugu 1 and Canggu 4 from North China summer-sown foxtail millet region was the minimum, while Canggu 4 showed the highest genetic distance from native cultivar Jinxiangyu coming from Inner Mongolia plateau. Generally, the genetic distance between cultivars from North China summer-sown foxtail millet region and those from Northwest early spring-sown foxtail millet region was relative large. The 12 major cultivars could be classed into two groups at the genetic similarity coefficient of 0.594. Group I included Jigu 12, Jigu 19, Canggu 4, Yugu 1 and Ai 88 from North China summer-sown foxtail millet region, and the remaining seven cultivars formed Group II. Clustering of the 12 elite cultivars was consistent with the eco-regions where they released. The population structure was in agreement with that of cluster analysis, suggesting that gene exchanges may occur among cultivars from summer-sown and spring-sown foxtail millet regions. In summary, cultivars from the same eco-regional origin had low genetic differences, while those from different ecological origins had large genetic differences. Genetic differences among cultivars within North China summer-sown region were relative lower than those from other ecological regions. A large genetic difference was observed between cultivars from North China summer-sown region and those from northwest early-maturing spring-sown region. The varietal exchange between summer-sown and early-maturing spring-sown should be strengthened to enlarge the genetic variation in summer-sown foxtail millet in North China. These findings could provide a basis for superior foxtail millet breeding and promoting the utilization of germplasm resources.

Key words: eco-region, foxtail millet, phenotypic evaluation, SSR marker, genetic diversity

摘要： 骨干谷子品种对谷子产业发展发挥了重要的作用,为了解其优异性状遗传基础及利用价值,选用来源于不同生态区的12个骨干谷子品种,进行表型鉴定和遗传差异分析。结果表明,12个来源于不同生态区的骨干品种在株高、穗长、穗粗、穗下节间长、单穗重、生育期以及黄色素含量等方面差异较大。79对SSR多态性标记共检测到258个多态性变异位点,平均3.265 8个;SSR标记多态性(PIC)的变幅为0.141 1~0.711 6,平均为0.510 1;其中PIC>0.5的SSR标记有50对,占多态性标记的63.3%。12份材料的遗传距离变幅为0.140 2~0.801 1,平均为0.473 7;来自华北夏谷区的豫谷1号和沧谷4号遗传距离最近,而沧谷4号和来自内蒙高原的地方品种金香玉距离最远;总体而言,华北夏谷区品种和西北早熟春谷区品种遗传距离相对较大。相似性系数为0.594时,12个品种可聚为两类,华北夏谷区的豫谷1号、矮88、冀谷19号、沧谷4号和济谷12聚为一类,来自西北春谷早熟区、晚熟区和东北春谷区的7个品种聚为一类,聚类分析结果和品种的生态类型具有较高的一致性。群体结构分析和聚类分析的结果相似,华北夏谷区品种和春谷区品种之间存在基因交流。总之,不同生态区来源品种间遗传差异较大,同一生态区来源品种遗传差异较小;华北夏谷区骨干品种之间遗传差异较春谷区品种遗传差异相对较小;华北夏谷区品种和西北早熟春谷区品种间遗传差异较大,丰富华北夏谷区遗传变异,应加强与西北早熟春谷区品种之间的交流。本研究结果为优异谷子品种培育及种质资源利用提供了一定依据。

关键词: 生态区, 谷子, 表型鉴定, SSR标记, 遗传多样性