小麦地方品种望水白抗赤霉病性的遗传分析

本文应用常规分析法研究了抗病品种望水白与感病品种中国春正反交F_1代赤霉病病小穗率的差异,用联合尺度测验分析了该组合的P_1、P_2、F_1、F_2、B_1和B_2世代抗赤霉病性的遗传模式及基因效应,估算了抗赤霉病性的基因数目。并用单体分析对望水白的抗扩展基因进行了染色体定位。全部抗性鉴定的材料采用田间剪颖滴菌接种,鉴定其抗赤霉病性,单体分析的F_2代还用了离体水培单花注射接种法。结果表明:小麦品种的抗赤霉病性是受细胞核基因控制的数量性状,有5-6对基因控制望水自的抗扩展性,分别定位在4A、5A、7A、7B和4D5条染色体上。2D染色体上的基因的作用还有待于进一步研究。望水白与苏麦3号属于不同的赤霉病抗源。

GENETIC ANALYSIS OF SCAB RESISTANCE IN THE LOCAL WHEAT VARIETY WANG-SHUI-BAI

Using the joint scaling test, the genetic model and the gene effects ofresistance to scab were analysed in the parents P_1 and P_2, the progeniesF_1, F_2and the two backcrossed B_1and B_2 of Wang-Shui-Bai (WSB) x ChineseSpring (CS). The number of genes controlling resistance to scab was estima-ted with the F_2and the B_1, B_2 and the chromosomal location of these resist-ance genes is determined by monosomic analysis. Two methods of inoculationwere used. Glumes-clipping in the field was done by dipping a pair ofscissors in the conidial suspension of Gibberell a Zeae, then cutting off asmall portion of the upper part of one of the glumes in the middle of thespike so as to enable a small drop of inoculum to drip into the floret.Individual-floret-injecting method in the laboratory was done by injectinginoculum into individual florets in the middle of the excised wheat spike whichwas placed in a bottle with clear water. Monosomic or disomic plants wereidentified by mitosis and meiosis observations. The results showed that theresistance to scab in the wheat variety seemed to be a quantitative charactercontrolled by nuclear genes. The additive-dominance model proved to besatisfactory in explaining the gnetic differences for the trait. There mightbe 5-6 genes for resistance in WSB. They were respectively located in 4A,5A, 7A, 7B and 4D chromosomes.