论文部分内容阅读
【目的】挖掘和分析芸薹种抗根肿病基因及基因间的互作关系,为芸薹种抗根肿病育种提供理论依据。【方法】以大白菜自交系‘BJN’为母本,芜菁自交系‘Siloga’为父本进行杂交获得F1。F1单株自交获得由140个单株构成的F2群体,用于遗传图谱构建。95个F2单株及其F3家系用于抗根肿病(CR)性状的QTL定位和上位性互作分析。利用1 214个分子标记和前人开发的与7个CR连锁的22个标记进行亲本间多态性筛选。根据作图群体的多态性标记基因型,采用JoinMap 4.0作图软件构建遗传连锁图谱。以采自甘蓝型油菜栽培地的根肿菌对2个亲本及其95个F2:3家系进行根肿病抗性鉴定。根据F3植株的发病等级,计算F2单株的平均发病指数(DI)。利用Windows QTL Cartographer 2.5软件,采用复合区间作图法检测抗根肿病QTL。利用基于混合线型模型的QTL Network 2.0软件进行互作关系分析。SPSS 18.0.0软件用于分析F2群体中QTL连锁标记的基因型与其相应个体平均DI值间的相关性。双因素方差分析方法分析QTL连锁标记的交互作用。通过单因素方差分析,采用最小显著差异法和q检验(SNK)多重比较QTL紧密连锁标记(sau_um026和BrID90197)组合成的9种基因型在根肿病抗性上的差异。【结果】抗病性鉴定表明‘Siloga’对根肿菌表现为抗病,而‘BJN’表现为感病。F2群体中根肿病发病指数呈偏正态分布,表明根肿病抗性表现为由主效基因存在的多基因控制的数量性状。利用检测到的261个多态性标记构建出一个包含222个标记和10条连锁群的芸薹种遗传图谱。该图谱总长度为1 152.6 cM,定位了与3个CR连锁的5个标记,覆盖了大白菜参考基因组的88.6%。通过QTL定位共检测到源于‘Siloga’的2个QTL位点,分别位于A3连锁群的主效QTL(qPbBa3.1)和A8连锁群的微效QTL(qPbBa8.1)。qPbBa3.1和qPbBa8.1的贡献率分别为19.02%和7.82%。qPbBa3.1区域内包含有抗根肿病基因CRa或CRb,而qPbBa8.1与Crr1毗邻。此外,检测到qPbBa3.1和qPbBa8.1间的上位性互作,互作效应为加性×加性,贡献率为6.58%。双因素方差分析表明,sau_um026与BrID90197间存在极显著差异(P=7.22×10-5),进一步验证了qPbBa3.1和qPbBa8.1间的互作效应。单因素方差分析表明,sau_um026和BrID90197的9种基因型间存在显著性差异(P=9.45×10-10)。多重比较结果表明,qPbBa3.1为抗病亲本‘Siloga’基因型的个体抗病性显著高于其他基因型,杂合基因型的高于感病亲本‘BJN’基因型,含有qPbBa8.1的个体抗病性得到加强。【结论】芜菁自交系‘Siloga’根肿病抗性受主效qPbBa3.1,微效qPbBa8.1,qPbBa3.1和qPbBa8.1间的加性×加性上位性互作效应的影响。
【Objective】 The objective of this study was to explore and analyze the interaction between Brassica oleifera L. and various genes related to clubroot disease and to provide a theoretical basis for the breeding of Brassica oleoresin against clubroot disease. 【Method】 F1 was crossed with ’BJN’, a Chinese cabbage inbred line ’Siloga’, as the male parent. The F1 population was self-pollinated to obtain a F2 population composed of 140 individuals for genetic map construction. Ninety - five F2 individuals and their F3 families were used for QTL mapping and epistasis interaction analysis of resistant to clubroot (CR) traits. Using 1214 molecular markers and 22 markers linked to 7 CRs developed by the former, the polymorphisms of the parents were screened. According to the polymorphism marker genotype of the mapping population, JoinMap 4.0 was used to construct the genetic linkage map. The clubroot disease resistance of two parents and 95 F2: 3 pedigrees was identified by root blight collected from Brassica napus cultivated land. The average disease index (DI) of F2 plants was calculated based on the disease grade of F3 plants. The QTLs for clubroot disease were detected by composite interval mapping using Windows QTL Cartographer 2.5 software. Analysis of interaction using QTL Network 2.0 software based on a mixed linear model. SPSS 18.0.0 software was used to analyze the correlation between the genotypes of QTL linkage markers in F2 population and their respective individuals’ mean DI values. Two - way analysis of variance (ANOVA) method was used to analyze the interaction of QTL markers. One-way analysis of variance (ANOVA) was used to compare the differences in the resistance of the edema disease to the 9 genotypes of the QTL closely linked markers (sau_um026 and BrID90197) using the least-significant difference method and the q-test (SNK). 【Result】 The results showed that ’Siloga’ was resistant to R. solani and ’BJN’ was susceptible to disease. The incidence of clubroot disease in F2 population showed a normal distribution, indicating that the clubroop disease resistance was characterized by the multiple genes controlled by the major gene. Using the detected 261 polymorphic markers, a genetic map of Brassica species containing 222 markers and 10 linkage groups was constructed. The total length of the map was 1 152.6 cM, locating 5 markers linked to 3 CRs, covering 88.6% of the reference genome of Chinese cabbage. Two QTLs originated from ’Siloga’ were detected by QTL mapping, which were located in the major QTL (QPbBa3.1) of A3 linkage group and QTL (QPbBa8.1) of A8 linkage group respectively. The contribution rates of qPbBa3.1 and qPbBa8.1 are 19.02% and 7.82% respectively. The qPbBa3.1 region contains the anti-club disease gene CRa or CRb, while qPbBa8.1 is adjacent to Crr1. In addition, the epistatic interaction between qPbBa3.1 and qPbBa8.1 was detected and the interaction effect was additive × additive, with a contribution rate of 6.58%. Two-factor analysis of variance showed that there was a very significant difference between sau_um026 and BrID90197 (P = 7.22 × 10-5), further verifying the interaction effect between qPbBa3.1 and qPbBa8.1. One-way ANOVA showed that there was a significant difference between the nine genotypes of sau_um026 and BrID90197 (P = 9.45 × 10-10). The results of multiple comparisons showed that the individual resistance of qPbBa3.1 to ’Siloga’ genotypes was significantly higher than that of other genotypes and that of heterozygous genotypes ’BJN’ with qPbBa8.1 Individual disease resistance has been strengthened. 【Conclusion】 The results showed that the resistance of clubroot ’Siloga’ to root disease resistance was affected by the additive × additive epistatic effects of qPbBa3.1, qPbBa8.1, qPbBa3.1 and qPbBa8.1 .