穗发芽率和发芽指数及STS标记Vp1B3在小麦抗穗发芽基因型鉴定中的应用

为了筛选抗穗发芽品种(系)并了解其抗性机制,应用整穗发芽法和发芽指数鉴定了33份小麦新品系的穗发芽抗性,以红粒品种京冬8号和京9428作为抗穗发芽对照,以白粒品种京411和中优9507作为感穗发芽对照,并结合共显性STS标记Vp1B3对其基因型进行检测.结果表明,穗发芽率(SGR)低于抗性对照京冬8号和京9428平均值(12.7%)的品系有7份,其中2份为白粒,5份为红粒.只有一份红粒品系CA0489的发芽指数(GI)低于抗性对照平均值(13.2%).应用STS标记Vp1B3共扩增出849 bp、569 bp和652 bp三种片段,分别属于抗穗发芽基因型Vp1Bb和Vp1Bc及感穗发芽基因型Vp1Ba,其频率分别为3%、18%和79%.红粒抗穗发芽品系CA0489属于Vp1Bb基因型和红色种皮休眠型,CA0481属于Vp1Bc抗穗发芽基因型,另外三份红粒抗穗发芽品系的抗性机理还需要进一步研究;白粒抗穗发芽品系CA0509和CA0459的抗性为非Vp1B3类型,其抗性可能与穗部性状和颖壳抑制物有关.

Identification of Wheat Genotypes with Pre-harvest Sprouting Tolerance by Combinated Analysis of Spike Germination Rate, Germination Index and Molecular Marker Vp1B3

To identify pre-harvest sprouting(PHS) tolerant wheat varieties(or lines) and to understand their mechanism of resistance,three methods,i.e.,spike germination rate(SGR),germination index(GI),and molecular marker Vp1B3,were used to screen the PHS tolerance of the 33 new wheat lines in comparison with two red grain tolerant cultivars Jingdong 8 and Jing 9428,and two white grain susceptible cultivars Jing 411 and Zhongyou 9507.Seven lines with lower SGR than the average value of PHS tolerant cultivars(12.7%) were identified,among which five lines had red grain and two lines had white grain.Only one red grain line CA0489 exhibited lower GI(12.8%) than the mean value of PHS tolerant cultivars(13.2%).Three types of DNA fragments,845 bp,569 bp and 652 bp,could be amplified by STS molecular marker Vp1B3 with frequencies of 3%,18% and 79% in all lines,and which belonged to resistance genotype Vp1Bb,Vp1Bc and susceptible genotype Vp1Ba,respectively.The red grain PHS resistance line CA0489 possessed both Vp1Bb tolerant gene and red grain related dormancy gene;red grain PHS resistant line CA0481 had Vp1Bc tolerant gene,but the mechanisms of the rest three red grain PHS resistant lines remain unclear.The two white grain PHS resistance lines CA0509 and CA0459 did not contain Vp1 tolerant gene,their PHS tolerance might be related to the characters of spike and the stayers excreted from glumes.