摘要
本文研究表明,甘蓝型油菜(B.napus L.)叶片形态偏离正常的孟德尔式遗传,正反交F_2 与回交B_2 世代之间性状分离结果呈现出显著差异,而且这种分离差异在高世代衍生家系间以及不同交配系统中和不同年度间表现一致。作者提出了“质核互作对异源基因配子的优先选择”假说以解释这种异常遗传行为。文中还详细讨论了其他一些假说的不适合性,以及前人在叶形遗传研究中可能存在的局限性。
Several generations of two crosses among two lines(P_1,P_3)with completed leaf and a line(P_2)with parted leaf in Brassica napus L. were sown in 1988—91, so as to study the inheritance of leaf shape. It was shown that the inheritance of leaf shape deviated from the Mendelian manner. The segregation ratios differed significantly between the reciprocal crosses in the F_2 generation as well as in the BC_2 generation. This was also true in, advanced generations and different years. The hypothesis of' preferential selection of heterogenetic gametes under the cytoplasmic—nuclear interaction”was proposed to explain the heredity mechanisms. It assumed that
the complementary allels Cc and L1 in the nucleus govern the inheritance of leaf shape. Gene C not only is dominant over C, but also sensitive to the plasmon;gene c is epistatic to nonallelic genes L/1 which control the lobing depth of
leaf. In the process from meioses to gamete maturity of tile F_1 individual, tile plasmon might accept more heterogenetic and fewer homogenetic gametes which both carry gene C. This disturbs randomness in the formation of the lyrate gamete CI. and the parted leaf gamete Cl. Thus, in the present study,the ratio of gametes heterogenetic and homogenetic with the plasmon was 2.4412:1, rather than 1:1 in Mendelian inheritance.
关键词
甘蓝型油菜
叶片形态
遗传
油菜
Brassica napus L.
Leaf shape
Non-Mendelian inheritance
Cytoplasmic-nuclear interaction
Epistatic gene
Heterogenetic gametes
