【作者】 李晶晶；

【导师】 吴建宇；

【作者基本信息】 河南农业大学 ， 作物遗传育种， 2008， 硕士

【摘要】 玉米穗粒腐病是一种危害严重的真菌性病害,该病不仅影响了玉米的产量和品质,而且其产生的次生代谢物已威胁到人畜健康。近年来随着对食品安全问题的普遍关注,玉米穗粒腐病已成为国内外研究中的热点问题。围绕玉米穗粒腐病抗性,利用分子数量遗传学等方法鉴别出一些抗病QTL,加深了对抗病性的认识。为了揭示多基因位点控制复杂性状的抗病机制,需要对抗病性状进行剖分。在课题组抗源筛选的基础上,首先利用分子标记辅助选择的方法选育出覆盖全基因组的一套导入系,结合抗性鉴定,选育出抗病近等基因系,进而开展玉米穗粒腐病抗性遗传研究。主要结果如下:1.导入系选育通过一次自交,四次回交。选用抗病自交系BT-1为非轮回亲本,感病自交系N 6为轮回亲本,其中利用均匀分布于玉米10个连锁群的109个SSR分子标记在BC₂F₁进行背景检测,随后根据BC₂F₁代背景选择的标记位点信息,并将标记增加到153个,在BC₄F₁对SSR标记位点监控,通过筛选只保留单个SSR标记位点,或连锁的几个SSR标记位点,剔除遗传背景中其他标记位点的单株或其后代,获得77个以N 6为背景、BT-1为供体的染色体片断导入系,这些导入系的遗传背景恢复率均在90%以上。2.在导入系的选育过程中,结合抗性鉴定,2006年春得到12个BC₄F₁抗病近等基因系,遗传背景恢复率达到90%以上,2007年用12个抗病近等基因系的回交后代BC₅F₁和17个BC₄F₁中抗性最好的1个近等基因系的自交BC₅F₂群体,通过田间接种鉴定和分子检测发现:同时含有第4染色体和第6染色体目标区域片段的单株表现为高抗,仅含有第4染色体或第6染色体目标区域片段的单株表现为抗性中等偏感,两条染色体上均不存在目标区域片段的单株严重感病,初步推断在第4染色体和第6染色体存在杭病基因。更多还原

【Abstract】 Fusarium ear rot is a fungal disease with devastating and widespread in the world, which not only affects yield and quality, but also generates the fumonisins that posing a potential threat to animal and human health.The most effective way to prevent this disease is resistant breeding, which depends on the resistant materials and resistance genes.It was showed that the inheritance of resistance to Fusarium ear rot was conditioned by polygenes from a few researches in the world. The single segment introgression lines were developed by using N6 and BT-1 as a recurrent parent and current parent, respectively, by marker assistant selection, and the resistant near isogenic lines were developed by the inoculation, the inheritance of resistance to Fusarium moniliforme ear rot in maize was studied by the near isogenic lines.The results are as follows:1.The Susceptible inbred line N6 was used as recurrent parent, and the resistant inbred line BT-1 as non- recurrent parent, phenotypic selection with marker assistant selection were used for selecting for the genetic background of N6. Crossing once, backcrossing 4 times, then got the 339 SSILs.2. The resistant near isogenic lines, 90% background of the recurrent parent was recovered in the BC4F1 generation by 153 SSR markers, were developed by the inoculation with marker assistant selection in 4 years. The inheritance of resistance to Fusarium moniliforme ear rot in maize was studied by the lines, and the results showed that the resistance genes were identified both in chr.4 and chr.6.更多还原