在构建QPM近等基因系过程中对回交群体的SSR标记选择

优质蛋白玉米(QPM)遗传基础狭窄,以普通玉米自交系为遗传背景培育opaque-2近等基因系是QPM种质改良的重要途径。本文利用SSR标记技术,以opaque-2基因序列为背景开发的特异SSR引物phi057和umc1066作为标记,对构建中的95个QPM近等基因系回交群体BC1F1和BC2F1进行目标基因选择。结果表明,SSR标记phi057对大多数回交群体中的opaque-2基因的选择是有效的;在少数回交群体,如(多黄29×CA335)×多黄29,SSR标记phi057和umc1066不能区分单株间的基因型变异,针对这些材料,需要进行更深入的研究或开发新的SSR。

SSR Marker Assisted Selection for opaque-2 Gene in Early Generations of NILs Development in QPM

The germplasm base of quality protein maize(QPM) is narrower. The available approach to enhance QPM germplasm is to convert normal maize inbred lines to opaque-2 NILs (near isogenic lines) assisted with molecular markers. The procedures of marker assisted selection for opaque-2 in early generations of backcrossing (BC₁F₁ and BC₂F₁) by SSR markers phi057 and umc1066 were developed. The results showed that the opaque-2 gene could be genotyped in most backcrossing populations by SSR marker phi057. Using this method, opaque-2 gene can be identified in most NILs populations. But the SSR markers phio57 and umc1066 can't distinguish homozygotes and heterozygotes in the BC1F1 of (Duohuang29×CA335)×Duohuang29. So, new SSR of the opaque-2 gene is needed to be developed for MAS.