论文部分内容阅读
赤霉病是最严重的大麦病害之一。由于赤霉病抗性是受多基因控制的数量性状(QTL),并且一些表型性状也影响大麦赤霉病的抗病,如棱数、株高和抽穗期等,所以抗赤霉病大麦品种的选育十分困难。为了明确加拿大六棱大麦中赤霉病抗性以及相关性状的QTLs,本研究在4年中对93个家系的DH作图群体中赤霉病抗性、呕吐毒素(DON)含量、株高、抽穗期和成熟期等相关性状进行调查,并利用分子标记(444个DArT和26个SSR标记)构建的连锁图谱对QTL开展复合区间作图。结果表明,本研究共检测到4个影响赤霉病的QTLs,其中,2个主要的QTLs定位在3H和7H染色体上,它们的加性效应为-3.44和-3.69,分别解释14.1%和17.5%的表型差异,总共解释31.6%的赤霉病抗性差异;另外2个QTLs定位于7H染色体上,但二者同时也与DON含量显著相关。此外,在3H、5H和7H染色体上确定了5个影响株高的QTLs,在2H、4H、5H和7H上确定了4个影响抽穗期的QTLs。同时发现2个赤霉病抗性QTLs和1个DON累积QTL与控制株高的QTLs聚集重叠,1个赤霉病抗性QTL和抽穗期QTLs重叠。这些与赤霉病抗性、株高及抽穗期等农艺性状紧密连锁的分子标记可进一步用于有效提高抗赤霉病大麦品种的选育效率。
Fusarium head blight is one of the most serious barley diseases. Because Fusarium head blight resistance is a quantitative trait controlled by multiple genes (QTLs) and some phenotypic traits also affect the disease resistance of FHBs such as the number of edges, plant height and heading date, Breeding of varieties is very difficult. In order to clarify the QTLs of Fusarium head blight resistance and its related traits in six-row barley of Canada, we studied the resistance of scab, DHF, DON, Heading stage and maturity stage. The QTLs were mapped by using linkage map constructed by molecular markers (444 DArT and 26 SSR markers). The results showed that four QTLs affecting scab were detected in this study. Among them, two major QTLs were mapped on 3H and 7H chromosomes with additive effects of -3.44 and -3.69, respectively, accounting for 14.1% and 17.5 % Of the phenotypic differences explained a total of 31.6% of the FH resistance differences; the other two QTLs were located on chromosome 7H, but both were also significantly associated with the DON content. In addition, five QTLs affecting plant height were identified on 3H, 5H and 7H chromosomes, and four QTLs affecting heading date were identified on 2H, 4H, 5H and 7H. At the same time, two QTLs for FHB resistance and one DON cumulative QTL were found to overlap with the QTLs for controlling plant height. One QTL for Fusarium head blight resistance and QTLs for heading stage overlapped each other. These molecular markers tightly linked with agronomic traits such as scab resistance, plant height and heading date can be further used to effectively improve the breeding efficiency of barley cultivars resistant to Fusarium head blight.