大豆7S球蛋白亚基与脂氧酶双缺失性状遗传解析

摘要

7S球蛋白是大豆最主要的过敏原蛋白,大豆脂氧酶是大豆腥臭味产生的原因,两者均是大豆食品深加工过程中有必要去除的成分.本研究以7S球蛋白的α′,α,β-亚基完全缺失的"1003-44"为母本,以脂氧酶Lox-1,2,3完全缺失的"SI0162"为父本,配制杂交组合,通过基因聚合育种技术,创制出7S球蛋白亚基与脂氧酶同时缺失大豆新种质资源,并分别对F1和F2种子进行遗传解析.结果表明:F1(1003-44×SI0162)种子表型性状,表现为7S球蛋白亚基缺失、脂氧酶不缺失性状;F2种子表型性状显示:7S球蛋白亚基缺失:野生型=375: 125=3: 1 (X2(0.05,1)=0.0964<3.84),F2种子脂氧酶缺失性状的分离比为Lox-1,2,3野生型: Lox-3缺失: Lox-1,2缺失:Lox-1,2,3缺失=282: 96: 93: 27,符合9: 3: 3: 1的独立分配定律(X2(0.05,3)=0.6275<7.81).说明7S球蛋白亚基缺失性状受1对显性等位基因控制,脂氧酶3个同工酶同时缺失,受lx1,lx2与lx3,2个隐性等位基因位点控制.利用ISDS-PAGE电泳技术对F2及F2: 7种子双缺失性状的连续跟踪筛选,获得了脂氧酶与7S球蛋白亚基双重缺失、并可稳定遗传的优良品系2个,说明这种双缺失基因聚合不影响大豆的正常生长发育,为大豆品质遗传改良提供理论、技术支持,对培育食品加工专用高值大豆新品种具有重要意义.%7S globulin subunit is the main allergen of soybean,lipoxygenase is the source of the beany flavor. Therefore,the 7S globulin subunit and lipoxygenases are necessary to be removed during the soybean processing. In this study,the α′,α,β subunit of 7S globulin complete deletion of "1003-44" as the female parent,"SI0162"lacking Lox-1,2,3 lipoxygenases complete of as the male parent,a cross was made to optimize these two traits, the new germplasm resources of double deficiencies in 7S globulin subunit and lipoxygenases were created. All 21 F1(1003-44×SI0162)seeds displayed the absence of 7S globulin subunit,and the presence of lipoxygenases, the distribution ratio of 500 F2phenotype for the absence and presence of 7S globulin subunit from selfed 21 F1 plants was 375: 125,fitting the ratio of 3: 1(X2(0.05,1)=0.096 4 <3.84). Moreover,the ratios of 4 phenotypes were at 282 of presence of Lox-1,2,3: 96 of absence of Lox-3: 93 of absence of Lox-1,2: 27of absence of Lox-1,2,3 in the F2(1003-44×SI0162)population well fit to 9: 3: 3: 1(X2(0.05,3)=0.627 5<7.81). These data supported the hypothesis that the absence of 7S was dominant to the presence of 7S globulin subunit. In addition,the absence of Lox-1,2,3 were recessive to the presence of Lox-1,2,3. Therefore,we concluded that the ab-sence of 7S globulin subunit was inherited as a single dominant trait,the absence of Lox-1,2,3 were inherited as 2 recessive traits. Furthermore,we obtained two double deficiency F2: 7lines of 7S globulin subunit and Lox-1,2, 3 double through long term screening by ISDS-PAGE. It suggested that the characters of 7S globulin subunit and Lox-1,2,3 did not affect the normal plant growth and seed development of soybean. This study not only provided genetic and phenotypic basis for breeding of soybean seed composition toward improvement of seed quality,but also benefited to cultivation of special high-value soybean variety for food processing.