云南铁壳麦的穗发芽抗性鉴定与分析

Identification and Analysis of Pre-Harvest Sprouting Resistance in Yunnan Hulled Wheat

为了解云南铁壳麦(Triticum aestivum ssp.yunnanense)的穗发芽抗性及其机制、筛选抗性材料,以白粒推广良种云麦53号为对照,采用整穗发芽、整粒发芽及分子功能标记的方法,鉴定了55份云南铁壳麦的穗发芽抗性及种子的休眠特性,分析了发芽指数(germination index,GI)在穗发芽抗性级别不同的材料间、分子功能标记基因等位变异间的差异及籽粒发芽率(germination percent,GP)在不同休眠级别的材料间的差异。结果表明,以整穗发芽率(spikes germination rate,SGR)为鉴定指标,在对照云麦53号的SGR达76.2%的前提下,云南铁壳麦除1份材料SGR为2%外,其他材料的SGR都为0,与对照相比,对穗发芽的抗性都很强。以GI为鉴定指标,供试云南铁壳麦对穗发芽的抗性则较弱,抗性材料较少,GI为15.5%~72.8%(对照的GI为65.7%),GI在抗性级别不同的材料间明显不同。以籽粒发芽率为依据,云南铁壳麦的种子休眠性可分为休眠、中度休眠、浅休眠和无休眠4级,GP在不同休眠级别的材料间也显著不同。用STS功能标记Vp1B3扩增出A带(652 bp)、C带(无带)的材料,其GI均与扩增出B带(569 bp)材料的GI有明显差异;用标记Vp1A3扩增出B带(170 bp)材料的GI与C带(无带)材料的GI也有明显差异,其他3个功能标记(Tasdr-B1、Tamyb10D1、Tamyb10D)扩增到不同带型材料的GI则无明显的不同,用分子标记获得的结果不能解释云南铁壳麦的穗发芽抗性或种子休眠特性的变化。

In order to evaluate the pre-harvest sprouting(PHS)resistance and related mechanisms of Yunnan hulled wheat(Triticum aestivum ssp.yunnanense)and screen out materials with high resistance to PHS,the PHS resistance and seed dormancy characteristics of 55 accessions of Yunnan hulled wheat were identified,with the white-grain variety Yunmai 53 as control,using methods of spike germination rate(SGR),seed germination percentage(GP)and functional molecular markers.We analyzed the differences in germination index(GI)among materials with different PHS resistance levels and with allelic variation of functional molecular markers,and the differences of GP among materials with different dormancy levels.The results showed that,compared with the SRG of Yunmai 53(76.2%),the SGR of Yunnan hulled wheat was 0,except for that of one accession(2%),indicating Yunnan hulled wheat accessions have strong PHS resistance.For GI,the PHS resistance of Yunnan hulled wheat(15.5%-72.8%)did not show that much difference from the control(65.7%),whereas GI varied significantly among different resistance levels.The seed dormancy of Yunnan hulled wheat accessions were divided into four levels:dormancy,moderate dormancy,weak dormancy and no dormancy based on GP,and GP also varied significantly among the four levels.There were significant differences for GI between materials with band A(652 bp)and band B(569 bp),and between materials with band C(no band)and band B(569 bp)when amplified by STS functional marker Vp1B3.Moreover,the GI was also obviously different between band B(179 bp)and C(no band)when amplified by STS functional marker Vp1A3.However,when amplified by Tasdr-B1,Tamyb10D1 and Tamyb10D,the variants did not associated with different GI.Therefore,the variations of PHS resistance or seed dormancy characteristics of Yunnan hulled wheat can not be clearly explained by molecular markers.