不结球白菜叶绿素含量的主基因+多基因混合遗传分析

Genetic analysis of chlorophyll content using mixed major gene plus polygene inheritance model in non-heading Chinese cabbage

对不结球白菜叶绿素含量进行遗传模式分析,为品质改良奠定基础。应用植物数量性状主基因+多基因混合遗传模型,以‘乌塌菜’和‘二青’为亲本配制的6个世代(P1、P2、F1、B1、B2和F2)为材料,对不结球白菜中叶绿素含量进行遗传模式分析。2年的研究结果表明,叶绿素含量受1对加性-显性主基因+加性-显性-上位性多基因控制。2011年,主基因的加性效应为9.59,显性效应为1.17,在B1、B2、F2世代中主基因的遗传率分别为22.86%、41.65%、61.24%,多基因的遗传率分别为59.18%、36.08%、24.30%。2013年,主基因的加性效应为4.48,显性效应为2.09,在B1、B2、F2世代中主基因的遗传率分别为5.66%、38.51%、26.29%,多基因的遗传率分别是64.99%、22.93%、52.08%。结论:不结球白菜叶绿素含量受1对加性-显性主基因+加性-显性-上位性多基因控制,以遗传效应为主,同时还受环境变异的影响。在不结球白菜叶绿素含量的群体改良中,可考虑对高叶绿素含量的单株进行定向选择或轮回选择,以提高育种效率。

Chlorophyll plays a fundamental role in the energy absorption and transduction activities of photosynthetic organisms, and is essential in growth and production of vegetable crops. However,little is known on the genetic model of chlorophyll content. Here, we performed genetic analysis of chlorophyll content in non-heading Chinese cabbage （Brassica campestris ssp. chinensis Makino）, and the results could contribute to the illustration for chlorophyll genetic model and exploration of new genes involving in regulation of chlorophyll content. Two cuhivars of non-heading Chinese cabbage, ＇ Wntaeai＇ with high chlorophyll content and＇ Erqing＇ with low chlorophyll content,were selected in this genetic analysis. Six generations（ P1 ,P2 ,F1, B1, B2 and F2 ）were achieved by hybridization and backcross. Chlorophyll contents of all plants were detected by SPAD-502 Plus Chlorophyll Meter. The mixed major genes plus polygene inheritance model were used for the genetic analysis of chlorophyll content. The results of two years （2011 and 2013 ）both showed that differences of chlorophyU contents between parents P1 and P2 were extremely significant,while chlorophyll levels of F1 population distributed between PI and P2, and were closer to P1. The trait of chlorophyll content in non-heading Chinese cabbage was controlled by the model of one additive-dominant major gene plus additive-dominant-epitasis polygene. Results of 2011 in plastic tunnel and 2013 in open field showed that the additive effects of major genes were 9.59 and 4.48 ,respectively. The dominant effects of two years were 1.17 and 2.09, respectively. In 2011, the heritabihties of major genes in the BI, B2 and F2 populations were 22.86% ,41.65% and 61.24%, respectively, and those of polygenes were 59.18%, 36.08% and 24.30%, respectively. In 2013, the heritabilities of major genes in the B1, B2 and F2 populations were 5.66%, 38.51% and 26.29%, respectively, and those of polygenes were 64.99% ,22.93% and 52.08%, respectively. Results of two years showed that environments had significant influence on the hereditary of chlorophyll content in non-heading Chinese cabbage. The environment variance in 2011 and 2013 was 14.46% and 21.63% ,respectively. Conclusion：The trait of chlorophyll content in non-heading Chinese cabbage was controlled by one additive- dominant major gene plus additive-dominant-epitasis polygene, and environmental factors play roles in the hereditary of chlorophyll content,which should be considered in the breeding process. A single directional selection or recurrent selection method could be used during cultivars improvements of non-heading Chinese cabbage, and the marker assisted selection method should be taken for production of high chlorophyll content lines.