不同环境中甘蓝型油菜种皮木质素含量的QTL定位

Identification of QTLs for Lignin Content of Seed Coat in Brassica napus L.in Different Environments

以甘蓝型黄籽油菜GH06和甘蓝型黑籽油菜中油821为亲本杂交,后代通过"一粒传法"连续自交7代构建重组自交系,2007年分别在重庆市北碚区和万州区2个试验基地种植重组自交系群体,利用本实验室已构建的遗传连锁图谱和复合区间作图法(CIM),对种皮木质素含量进行测定及QTL定位分析。结果表明,在2个环境中共检测到12个种皮木质素含量相关的QTL,分别位于4个不同的连锁群,单个QTL可解释性状表型变异的4.50%～8.79%;在第3连锁群上检测到1个QTL与同一标记EM19ME23/130连锁,其余10个QTL位置不同;在北碚检测到的QTL主要分布于第20连锁群,在万州检测到的QTL主要位于第3连锁群;部分种皮木质素的QTL与种胚类黄酮和种皮色泽的QTL位于相近区间,在北碚和万州种皮木质素含量与种胚类黄酮存在极显著和显著正相关关系。甘蓝型油菜种皮木质素含量表现为多基因控制的数量性状,基因表达受环境影响较大;油菜种皮木质素合成和类黄酮的积累可能受相同关键基因调控或者具有部分相同的合成代谢途径。

The objective of this study was to identify QTLs for lignin content of seed coat in Brassica napus using the composite interval mapping （CIM） method. The recombinant inbred lines （RIL） population derived from a cross between black-seeded male parent cultivar Zhongyou 821 and yellow-seeded female parent line GH06 was established by selfing for seven successive generations with single seed propagating from F2. The population was grown at Beibei and Wanzhou in Chongqing in 2007. The QTLs of seed coat lignin content in two environments were detected using the genetic map constructed in 2007. A total of 12 QTLs for seed coat lignin content were located on the four linkage groups, each of them explained 4.50–8.79% of phenotypic variation. One QTL located on linkage group （LG） 3 was linked with the same marker EM19ME23/130 in two environments, other QTLs had different locations between two environments. The QTLs found in Beibei were mainly distributed on LG 20, and the QTLs detected in Wanzhou mainly distributed on LG 3. The QTLs for flavoid contents in embryo and seed color were located in the nearly region with some QTLs for seed coat lignin content. The correlation analysis showed the lignin content of seed coat had significantly and positively correlated with flavoid content of embryo in different environments. In conclution, （1） the seed coat lignin content is controlled by many minor-effect genes, with a genetic pattern of quantitative trait, and the expression of the QTL is affected by environmental factors greatly;（2） the syntheses of lignin in seed coat and flavoid of embryo are probably controlled by the same genes or have the same pathway partially.