水稻基部伸长节间性状与茎秆机械强度的相关分析和QTL定位

分析水稻品种‘沈农265’和‘丽江新团黑谷’杂交的F2群体基部第二节间茎秆机械强度与该节间形态和茎秆解剖结构的相关性,并对基部第二节间机械强度和相关性状进行QTL定位的结果表明：机械强度与茎粗、茎壁面积、茎壁厚度、大小维管束数目、大小维管束面积、大小维管束韧皮部面积、大小维管束木质部面积呈显著或极显著的正相关,与节间长度呈极显著的负相关,而与茎秆扁平率的相关不显著。采用复合区间作图,从研究的14个目标性状中检测到18个QTL。控制基部第二节间的抗折力的QTL检测到4个,位于第4、7、9和10号染色体上,可解释遗传变异的12%～23%。在第4和第7染色体上的相同区间上还同时检测到了控制茎壁性状和维管束性状QTL,贡献率在12%～21%之间。说明这两个位点是控制基部第二节间机械强度的重要区域,也是茎壁性状、维管束性状与机械强度高度正相关的遗传学基础。

Correlation between Traits of Basal Elongating Internodes and Culm Mechanical Strength and QTL Location in Rice

The correlation between the culm mechanical strength of basal second internode and related morpho- logical and anatomical traits were analyzed in an F2 population, which was derived from a cross between super japonica rice ‘Shennong265＇ and japonica rice cultivar ‘Lijiangxintuanheigu＇. And QTLs detection of these traits were employed in this population. The conclusion showed that culm strength was positively correlated with stem diameter, area of culm wall, wall thickness and vascular bundle characters, but negatively correlated with internodes length, and no significant correlation to oblate rate. A total of 18 QTLs for 14 traits were detected by composite interval analysis, including 4 QTLs for culm strength of the basal second internode on chromosome 4, 7, 9, and 10. The variances explained by each QTL from 12% to 23%. The QTLs controlled some culm and vascular bundle traits were detected on the same area on chromosome 4 and 7. The phenotypic variations （VE） explained by individual QTL ranged from 12% to 21%. All the information suggests that these QTLs are important for the culm strength of the basal second internode, and are the important genetic basis of the positive correlation between culm, vascular bundle and stem strength traits.