糯玉米耐贮藏相关性状的主效QTL定位

为挖掘、利用玉米耐贮藏基因资源,对糯玉米组合N7×N32的216个F2单株种子进行2年的常温贮藏,并以贮藏后种子的单位质量电导率和发芽率为耐贮藏性指标,建立极端耐与不耐贮藏BSA混池.首先筛选在2个BSA混池间有多态性的引物,后在多态引物所在的染色体上增加引物,以F2为作图群体,构建分子标记连锁图谱;同时结合测得的F2...

Major QTL mapping for storability related traits in waxy corn

To explore and utilize storability gene resources, 216 F₂ ear seeds of waxy maize combination N7 × N32 were stored at room temperature for 2 years. The electroconductibility per weight and germination percentage of F₂ seeds after storage were used as storability indexes, and the DNA pool of extreme storability was formed. Primers with polymorphism between the two BSA pools were screened, molecular marker linkage map was constructed by adding primers on chromosomes of polymorphic primers using F₂ as the mapping population. Furthermore, combined with the seed storability data of 216 F₂ individuals, QTL related to storability were detected by composite interval mapping. The results showed that: 1)Two SSR primers with polymorphism between DNA pools were found from 600 primers, which were located on chromosomes 4 and 6, respectively; 2)A SSR linkage map containing 39 markers with a total length of 234. 9 cM was constructed by adding 200 primers on chromosomes 4 and 6; 3)Seven QTL were detected on chromosomes 4 and 6. Among them, two QTL(qCE-4-1 and qGP-4-1)of two indexes were simultaneously located in the region of bnlg1265~bnlg1755 on chromosome 4, with LOD values of 19. 3 and 18. 1, accounting for 30. 5% and 25. 9% of phenotypic variation, respectively. Moreover, two QTL(qCE-6-1 and qGP-6-1)were simultaneously screened in umc1014~bnlg1154 of chromosome 6, with LOD values of 11. 2 and 8. 2, accounting for 15. 0% and 10. 3% of phenotypic variation, respectively. This study provides a theoretical basis for the fine mapping of QTL and molecular marker assisted selection of new storability varieties.