甘蓝型油菜DH群体种子活力性状的遗传分析

高种子活力是决定后期植株优良形态建立和作物高产的基础。为明确甘蓝型油菜种子活力的遗传规律，本研究选用两个发芽势差异较大的甘蓝型油菜中双11号和R11配制杂交组合，构建了包含280个株系的甘蓝型油菜DH群体。利用建立的室内种子萌发检测系统，对4个种子活力评价指标，包含萌发曲线下面积（area underthe germination curve AUC)、平均发芽时间（mean germination time MGT)、发芽率达到50%所用的时间（time taken for 50% seeds to germinate, T50）、发芽率从16%至84%所用的时间（time between 16% and 84% germination, U8416），采用主基因+多基因混合遗传模型及偏度和峰度分析方法对种子活力评价指标进行遗传分析。结果表明，萌发曲线下面积受3对主基因+9对微效多基因控制，决定该性状的基因间存在着重叠作用，主基因的遗传率达74.88%，受环境影响较小；平均发芽时间和T50均受2对主基因+微效多基因控制，微效基因的数目分别为13和14对，主基因的遗传率分别为64.20%和64.53%，受环境影响偏大；U8416受4对主基因+8对微效多基因的控制，4对主基因的加性效应均表现为正效应，且决定该性状的基因间存在着互补作用，表明当这些基因同时存在时，基因的加性效应可以增强。主基因遗传率高达87.57%，表明主基因的遗传效应明显，受环境影响较小。研究表明，决定种子活力水平各萌发性状均是由主基因+多基因调控，并且各萌发性状的基因间均表现互作效应，为了使互作的基因间有更多的重组机会，在低世代的选择强度均不宜太大。

Genetic analysis of seed vigor in a doubled haploid population of Brassica napus L.

High seed vigor is the basis for plant establishment and determines high yield of crops in later stag?es. To better understand the genetic mechanism of seed vigor in rapeseed, a doubled haploid (DH) population con? sisting of 280 DH lines derived from cultivar Zhongshuang11 and a line R11 with contrasting germination potential was phenotyped using a seed germination vigor detection system. Four effective indicators of seed vigor, including the area under the germination curve (AUC), the mean germination time (MGT), the time taken for 50% seeds to ger? minate (T50), and the time between 16% to 84% germination (U8416), were assessed. The inheritance was analyzed by the Mixed Major Gene plus Polygene Inheritance model. The skewness and kurtosis analysis were also carried out. The results showed that AUC was controlled by 3 major genes and 9 minor polygenes, with overlapping effects. The heritability of the major genes was 74.88%, indicating the trait was less influenced by the environment. MGT and T50 were controlled by 2 major genes, and the number of polygenes with minor effects was 13 and 14, and the heritability of major genes was 64.20% and 64.53% respectively, indicating that they were easily influenced by the environment. U8416 was controlled by 4 major genes and 8 minor polygenes. All 4 major genes had positive addi? tive effect on the trait with complementary effect, indicating that additive effect of genes could be enhanced when these genes coexisted. The heritability of the main genes was as high as 87.57%, indicating that the genetic effect of the major genes was significant and the trait was less influenced by the environment. The germination traits that de? termine the level of seed vigor were regulated by the major gene + polygenes, and the genes of each germination trait showed an interactive effect. In order to provide more recombination opportunities among the interacting genes, the selection intensity in the early generation should not be high.