玉米胚乳突变基因与互作对籽粒成份的影响 Ⅲ.su_1基因与sh_2、bt_2基因的互作效应及其利用价值

The Effects of Maize Endosperm Mutant Genes and Gene Interactions on Kernel Components Ⅲ.The Interactions of su_1 with sh_2 and bt_2 Genes and Their Values in Maize Quality Improvement

研究了su_1基因与sh_2,bt_2基因互作对玉米籽粒粒重及营养成份的影响,探讨了这些互作效应对玉米品质育种的利用价值。结果表明:su_1基因与sh_2,bt_2基因互作大幅度降低籽粒百粒重,增加可溶性糖、还原糖和蔗糖含量,降低淀粉含量,增加蛋白质及蛋白质组分中清蛋白、球蛋白和谷蛋白含量,降低醇溶蛋白含量。籽粒氨基酸组成中,天门冬氨酸、谷氨酸、丙氨酸、亮氨酸、赖氨酸、精氨酸等氨基酸受基因互作影响较大。籽粒发育过程中双突变体一般表现为:粒重早期与正常型及单突变体相差不多,但后期增长缓慢;淀粉、醇溶蛋白早期含量较低,后期增长幅度亦较小;蛋白质含量下降量较小;可溶性糖及还原糖早期含量较高,后期下降速度随时期或基因组合而异。研究表明,su_1基因与sh_2、bt_2基因互作可以进一步提高籽粒营养成份,对玉米品质改良具有特殊的利用价值,但提高粒重是这类基因互作效应应用的关键。

The effects of interactions of su_1 with sh_2 and bt_2 genes on 11 kernel characterswere studied and their values in maize quality improvement were discussed. The resultswere as follows: The interactions of su_1 with sh_2 and bt_2 genes could reduce 100-kernelweight significantly, increase the contents of soluble sugar, reducing sugar, sucrose,protein. albumin, globulin and glutelin greatly. It could also reduce the contents ofstarch and zein. Among the 17 amino acids determined, Aspartic acid, Glutamic acid,Alanine, Leucine, Lysine and Arginine were more prominently affected by gene interactions.The changing trends of 6 kernel characters during the process of kernel development insu_1 sh_2 and su_1 bt_2 double mutants, when compared with their normal counterparts and singlemutants, could be described as follows: 100-kernel weight increased slowly, proteincontentdecreased slowly; the contents of starch and zein were lower at the early stage, followed bya slight increase, the contents of soluble and reducing sugar were higher at the earlystage and then had a constant decrease, but the decreased speeds varied with the genecombinations and the developing stages. The results indicated that the interactions of su_1 withsh_2 and bt_2 genes could be utilized in the improvement of maize quality, but how tomaintain the kernel weight is a question need to be resolved.