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。

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.

国家自然科学基金项目(30571169)、948重大专项(2003- Q03-3)