Identification Of QTL For Gain Yield And Yield Components And Analysis On Combining Ability Using Introgression Line Of Maize

A total of 56 introgressions lines (ILs) from 413 introgression lines (BC4F4), which were derived from combinations between Ye478 (the rectrrent parent) with donors (B73,Ji1037,sh15,Zhongzi01,87-1,Qibai80,Mo17,Dan340 and Qi319), repectively, were significantly different with Ye478 in grain yield (GY) and its components based on the field phenotypes from three locations, and were selected as studied materials. The genotypes of the 56 ILs were assayed with 173 polymorphic SSR markers. In addtion, three testcross lines from three heterotic groups, Mo17, Huangzao 4 and Dan340, were repectively selected to cross with the set of ILs in order to estimate combing ability of these ILs. QTL for yield and yield components were identified using phenotypic data from both ILs and tcross propriess by Icimaping sofeware. Main results were listed as following.1. A total of 56 introgression lines were identified that these lines were significantly different from Y478 in grain yield (GY) and its components under the p<0.01 level in three locations.2. The genomic screening using 173 SSR markers showed that 415 segments from donors were introgressed into Ye478. The introgressed smallest segment is 5.65 cM and the longest one is 268.05 cM. The number of introgressed segment of per se line was from 1 to 16. And average 92.80% genetic background was recoved into Ye478. A total of 87 segments were introgressed into chromosome 1, but less number segments (total of 15 segments) were introgressed into chromosome 2.3. Basing on phenotype data of grain yield (GY) and its components, a total of 75 QTL were detected, in which 30 QTL were consensus in ILs population and TC population. Total of 11 QTL for grain yield per ear were identifed with contributions to phenotypic variation from 3.01%-16.39% and with additive effect from -38.04 to 9.44 g. In 15 QTL for row number, range of additive effect was from -1.55 to 0.83 and phenotypic variation of individual QTL was between 5.20% and 18%; In 13 QTL for kernel number per row, range of additive effect is from -5.12 to 3.96 and phenotypic variation of every QTL is between 4.82% and 19.88%; In 8 QTL for 100 kernel weight, range of additive effect was from -4.66 to 4.10 g and phenotypic variation of every QTL was from 6.69 to 14.73%; additive effect of the 19 QTL for ear length range from -3.42 to 3.56 and phenotypic variation of every QTL is between 4.69 and 24.01%; In 9 ear length QTL, additive effect was between -0.41 and 0.22 cm; the phenotypic variation of each of QTL was between 6.10 to 14.90%.4. GCAs of introgression lines were remarkedly different. GCA for grain yield of ILs varied from -15.31g (IL2) to 15.34g (IL40). The SCA for grain yield was significantly different between introgression line and TC, the range of them was from -27.39 (IL45×Huangzaosi) to 15.64 g (IL45×Mo17).5. Seven ILs whose yield and yield traits components surpass current parent (Ye478) were selected, they are IL28,IL39,IL40,IL43,IL44,IL45,IL48. Experiment results show that yield and yield traits components QTL were detected in them IL39×Dan340,IL48×Mo17 and IL46×Huangzaosi that are higher combinations in SCA can be applied in breeding.