利用小麦单染色体代换系研究赤霉病抗性和抑制毒素产生的基因

由赤霉菌引起的小麦赤霉病是小麦生产的主要病害之一,小麦赤霉病抗源十分贫乏,而且多数表现为多基因遗传,在小麦育种中较难应用。从小麦近缘属种中寻求赤霉病抗性基因并把它引入栽培品种中,有重要的学术意义和经济价值。本研究以来自抗病小麦材料PI481521和栽培小麦Langdon杂交得到的14个4倍体小麦单条染色体代换系为试验材料,进行室内赤霉病的抗性鉴定,同时用脱氧雪腐镰刀菌烯醇(DON)试剂盒来测定接种后籽粒中的毒素含量。表型鉴定结果表明,14个代换系的抗病性存在较大的差异,其中代换系LDN(PI481521-3A)和LDN(PI481521-7B)分别在感染小穗数和小穗感染百分率上与抗性亲本无显著性差异,不存在抗病性高于抗性亲本的类型;毒素含量分析表明,2个亲本的毒素含量没有显著差异,各代换系的毒素含量均高于抗性亲本PI481521、LDN(PI481521-1A)、LDN(PI481521-2A)及LDN(PI481521-6A)的毒素含量较高,与2个亲本存在显著差异。这一鉴定结果为下一步抗性基因和毒素基因的定位研究提供了基础材料,对赤霉病抗性指标进行相关性分析,发现小穗感染百分率与麦粒毒素含量呈显著正相关。因此,在田间进行抗赤霉病种质筛选及抗病育种后代选择时,可以小穗感染百分率作为衡量指标以简化操作程序。

Identification of Chromosomes Responsible for FHB and Mycotoxin Production in Durum Wheat

Wheat Fusarium head blight(FHB),caused mainly by Fusarium graminearum and Fusarium culmorum,is a serious disease problem.The resistance resoure to FHB,however,is very poor.USDA geneticist Steven Xu produced a set of lines LDN(PI481521)].Each line had a different pair of chromosome from PI481521 substituted for the corresponding Langdon durum chromosomes.The purpose of this study was to determine if any of the LDN(PI481521) lines showed useful level of resistance of FHB.We test these lines for response by inoculating with Fusarium graminearum in the greenhouse.Inoculation was accomplished via the single spikelet method.In the test,some lines differed significantly.Two lines,LDN(PI481521-3A) and LDN(PI481521-7B),were consistently less susceptible and another two, LDN(PI481521-2A) and LDN(PI481521-6A),were more susceptible than the parent Langdon durum,which itself showed an intermediate FHB reaction.Also,these inoculated spikelets were detected by using Beacon Analytical Systems DON plate kit to analysis the mycotoxin.The results showed two lines LDN(PI481521-3A) and LDN(PI481521-7B) were the lowest amount of mycotoxin among the substitution lines,So there is a strong correlation between FHB severity and Don contents.Consequently,the genes responsible for or resistant to FHB and inhibition of mycotoxin production was preliminary localization.