烟草重要真菌性病害抗性基因的发掘和人工选择响应

发布时间：2018-04-22 18:18

本文选题：烟草黑胫病 + 烟草赤星病　；参考：《中国农业科学院》2016年硕士论文

【摘要】：烟草黑胫病和赤星病是危害烟草生产的两大主要真菌性病害,给烟叶生产带来极大困扰和经济损失,而培育抗病品种就是有效解决这一问题的根本途径。本研究以黑胫病抗性品种Beinhart1000-1为母本,感病品种小黄金1025为父本进行杂交、回交和自交,构建BC2F2,BC2F3回交群体,进而利用SSR分子标记进行黑胫病抗性位点QTL定位;同时对我们之前定位到的赤星病抗性主效QTL进行了人工选择响应研究,初步评价了相关分子标记的育种价值,为进一步开展分子标记辅助选择奠定了良好的基础。研究结果如下:(1)利用黑胫病抗源材料Beinhart1000-1和感病材料小黄金1025配制杂交组合,并以小黄金1025为轮回亲本,通过一系列杂交、自交和回交并结合分子标记辅助选择,选择出一个优良BC2F1黑胫病抗性单株,进而构建120份BC2F2及BC2F3群体。对两群体进行多年多点苗期和大田期共五次黑胫病0号生理小种接种鉴定,并利用筛选出的119对多态性引物扩增BC2F2单株。利用MapQTL 6.0提供的MQM模型法和MapChart 2.2进行作图,构建两条烟草连锁群,1号连锁群共含6个标记全长15.36 cM,2号连锁群含18个标记全长135.97 cM,并检测到3个与黑胫病抗性相关的QTL,其中两个位于1号连锁群上,一个位于2号连锁群上。(2)利用与主效QTL紧密连锁的分子标记J9和J4,分析随机群体、人工选择群体和自然群体中响应分子标记的等位基因频率,研究相关标记位点在不同群体中的等位基因变化规律。结果发现:(1)赤星病抗性主效QTL等位基因在不同选择强度(5%、10%和20%)的正向选择条件下都发生了显著性偏分离,其中在10%的正向选择强度下偏分离显著性最高。(2)在不同世代(F3、F4、F5和F6)的赤星病抗性育种选择群体中,J9位点抗病亲本等位基因型频率显著高于感病亲本基因型频率,表明来源于抗源净叶黄的主效抗性QTL与赤星病抗性显著关联。(3)在198份自然群体中,包括烟草赤星病抗性品种中烟86、单育二号在内的50份烟草种质携带与抗源净叶黄相同的基因型,表明该主效QTL被广泛应用到烟草赤星病抗性改良中。本研究充分验证了之前定位到的主效抗病QTL的准确性。
[Abstract]:Tobacco black shank disease and red spot disease are two major fungal diseases that harm tobacco production, which brings great troubles and economic losses to tobacco production, and breeding resistant varieties is the fundamental way to solve this problem effectively. In this study, the black shank resistant variety Beinhart1000-1 was used as the female parent, and the susceptible cultivar Xiaojin 1025 was used as the male parent to cross, backcross and self-cross. BC2F2C2F3 backcross population was constructed, and then SSR molecular markers were used to localize the black shank disease resistance site (QTL). At the same time, we studied the artificial selection response of the red spot disease resistant QTL, and preliminarily evaluated the breeding value of the related molecular markers, which laid a good foundation for further development of molecular marker-assisted selection. The results are as follows: (1) using the black shank disease resistant material Beinhart1000-1 and the susceptible material Xiaoguang 1025 to prepare the hybrid combination, and taking Xiaojin 1025 as the recurrent parent, through a series of crosses, self-crossing and backcrossing, and combining with molecular marker assisted selection, An excellent BC2F1 black shank resistant plant was selected and 120 BC2F2 and BC2F3 populations were constructed. The two populations were inoculated for five times at the seedling stage and field stage for many years, and the single plant was amplified by using 119 pairs of polymorphic primers. Using the MQM model method provided by MapQTL 6.0 and MapChart 2.2 to map, Two tobacco linkage groups were constructed. The linkage group 1 contained 6 markers with a total length of 15.36 cm, and the linkage group 2 contained 18 markers with a total length of 135.97 cm. Three QTLs related to the resistance to black shank disease were detected, two of which were located on the linkage group 1. The allelic frequencies in random populations, artificially selected populations and natural populations, were analyzed using molecular markers J9 and J4, which were closely linked to major QTL. To study the variation of alleles of related marker loci in different populations. The results showed that the dominant QTL allele of the resistance to red spot disease was significantly deviated under the positive selection conditions of 10% and 20% of the different selection intensities. The frequency of allelic alleles of resistant parents at J9 locus was significantly higher than that of susceptible parents in different generations of red spot resistance breeding selection population (F3F3F4F5 and F6) with 10% of positive selection intensity (P < 0.05), and the frequency of allelic alleles of resistant parents was significantly higher than that of susceptible parents (P < 0.05), which was significantly higher than that of susceptible parents (P < 0.05). The results showed that the main effect resistance (QTL), which was derived from the resistance to net leaf yellow, was significantly associated with the resistance to red spot disease, and was significantly associated with the resistance to red spot disease in 198 natural populations. 50 tobacco germplasms, including Zhongyan 86 and Danyu 2, carried the same genotypes as those resistant to net leaf yellow, indicating that the main effect QTL was widely used in the improvement of tobacco red spot resistance. This study fully verified the accuracy of the previously identified QTL.
【学位授予单位】：中国农业科学院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S435.72

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