花椰菜内叶盖球性状的主基因＋多基因遗传分析

Analysis on cauliflower's trait for inner leaves to cover curd by means of mixed major gene plus polygene genetic model

为明确花椰菜内叶盖球性状的遗传规律,选择内叶盖球度高的花椰菜高代自交系与内叶盖球度低的花椰菜多代自交稳定纯系构建P_1、P_2、F_1、BC_1、BC_2和F2的6个联合世代群体,利用植物数量性状主基因+多基因联合分离分析方法,研究控制花椰菜内叶盖球性状的基因分离规律。两年的研究结果显示:花椰菜内叶盖球度性状由2对加性-显性-上位性主基因+加性-显性-上位性多基因控制(符合E-0遗传模型),其中两对主基因具有明显的负向加性效应;两对主基因的显性效应则分别为正向和负向,且第一对主基因显性度相对较高;两对主基因具有明显的负向互作效应。2012年,BC_1、BC_2和F2的主基因遗传率分别为55.96%、74.84%和81.09%,广义遗传力分别为84.99%、84.11%和89%,环境变异占比相对较小;2013年,BC_1、BC_2和F2的主基因遗传率分别为69.95%、70.96%和84.27%,广义遗传力分别为79.43%、80.91%和84.28%,环境变异占比相对较小。表明花椰菜内叶盖球性状的遗传主要受到2对主基因+多基因的控制,且主要受主基因遗传的影响,整体受环境影响较小,本研究为以内叶盖球性状为育种目标的花椰菜育种提供了科学依据。

In order to clarify a genetic law of cauliflower’ s trait for inner leaves to cover curd,6 generations（P1,P2,F1,BC1,BC2 and F2） were selected from cauliflower parents having high/low degrees for inner leaves to cover curd,and a segregation law of genes controlling the curd-covering inner leaf trait was investigated by using mixed major gene plus polygene genetic model. The two-year research showed that the inner leaf trait was controlled by two-pair additive-dominant-epitatic major genes plus additive-dominant-epitatic polygenes（tallying with the E-0 model）,and the two-pair major genes had an obvious negative additive effect; The two-pair major genes’ dominant effects were respectively positive and negative, and the 1 st pair major genes had a relatively high degree of dominance; Both pair major genes were obvious in negative interaction. In 2012 the heritabilities of the BC1,BC2 and F2 major genes were 55. 96%,74. 84% and 81.09% respectively, their broad heritabilities were 84.99%,84. 11% and 89% respectively, and the environmental variation accounted for relatively small proportion; In 2013 the heritabilities of the BC1,BC2 and F2 major genes were 69. 95%,70. 96% and 84. 27%respectively, their broad heritabilities were 79. 43%, 80. 91% and 84. 28% respectively, and also the environmental variation accounted for relatively small proportion. From the above results it was concluded that cauliflower ’ s trait for inner leaves to cover curd was controlled mainly by two-pair major genes plus polygenes,the major genes ’ heritabilities were relatively high, and effects of environmental factors were less, which provides a scientific foundation of cauliflower breeding for cold resistance.