| High yield as the primary goal of Maize breeding. Since yield trait was a kind of quantitative traits controlled by multiple-genes, using conventional genetic methods to operate is more difficult, which greatly limited the maize high yield breeding process.With the development of molecular biology, much research have been carried out and identificated lot QTL but most mapping populationes are relatively small , most of them are temporary separation groups, so the result of the QTL is multiple and not so accurate. So in this study, we constructed 280 F7 families derived from recombinant inbred lines between Ji846 and Ye3189 as the mpping population, and evalucated the yield and related characters in experimental bases of northeast agricultural university in Harbin for consecutive three years, we selected Bin2.04-2.05, Bin3.04-3.06, Bin7.01-7.02, Bin8.01-8.02 and Bin9.01-9.04 as the main fragments to increase the the number of SSR markers and used complex limited route graphical method to analyse the QTL associated with yield and related characters, on the base of the initial mapping of yield and related characters, and the markers distribution of original drawing constracted by Wang Xia(2009), the main results are as follows:1.Complex analysis of variance based on phenotypic data of consecutive three years showed that it has reached very significant levels between 10 yield traits and related traits within the relationships between families. The range of traits variation showed a significant tragreive segregation phenomenon. The coefficient of variation ranged between 6.13%-18.01%, the order from maximum to minimum is ear height>ear weight>grain yield per plot >100-Kernels weight>kernels per row>ear length>plant height>cob diameter>row number>ear diameter. Broad sense heritability of all traits ranged between 50.76%-82.81%, the maximum is row number, and the minimum is grain yield per plot. There were six plot yields of families in different years have shown a stable heterosis, the pedigree number respective were 2, 10, 27,122,257 and 321, while some yield related traits also showed stable heterosis, accounting for 2.14% in the families.2.A linkage map (2638.3cM distance; 15.8cM average interval) constructed with 117 SSR and 50 AFLP markers basedon the map of Wang Xia (2008). The marker numbers on each chromosome were 19, 22, 19, 14, 11, 15, 12, 22, 18 and 15. The average distance between markers on each chromosome were 18.4 cM, 16.5 cM, 15.4 cM, 15.9 cM, 16.2 cM, 18.2 cM, 10.8 cM, 15.0 cM, 13.6 cM and 17.0 cM.3.108 QTL associated with 10 characters were identified via composite interval mapping method and index of the data of the average yield of 2007, 2008 and 2009. QTL associated with plant height was 10 on chromosome 2, 3, 6 and 8, genetic contribution is 3.80%～16.22%; QTL associated with ear height was 15 on chromosome 2, 3, 6 and 8, genetic contribution is 4.40%～21.06%; QTL associated with ear diameter was 13 on chromosome 2, 3, 7 and 8, genetic contribution is 3.97%～11.15%; QTL associated with axis diameter was 9 on chromosome 1, 3, 8, 9 and 10, genetic contribution is 3.43%～10.57%; QTL associated with axis diameter was 9 on chromosome 1, 3, 8, 9 and 10, genetic contribution is 3.43%～10.57%; QTL associated with ear rows was 14 on chromosome 2, 3, 5, 7 and 9, genetic contribution is 3.26%～10.49%; QTL associated with axis diameter was 9 on chromosome 1, 3, 8, 9 and 10, genetic contribution is 3.43%～10.57%; QTL associated with row grains was 6 on chromosome 3, 4, 6, 7 and 8, genetic contribution is 3.81%～5.98%; QTL associated with ear weight was 7 on chromosome 2, 3, and 7, genetic contribution is 3.96%～6.81%; QTL associated with 100-seed weight was 10 on chromosome 2, 4, 7 and 8, genetic contribution is 3.79%～13.02%; QTL associated with block yield was 5 on chromosome 2, 3and 6, genetic contribution is 3.63%～5.36%. The chromosome 2, 3, 7 and 8 were the dense region of the QTL location, QTL on each chromosomes are 21, 21, 17 and 14 accounted for 66.97%.The Bin2.00-2.01,Bin2.04-2.05,Bin3.05-3.09,Bin7.01-7.02 and Bin8.05-8.07 were the intensive QTL region of the four chromosomes.4.The study identified four stable expressing QTLs.The QTL (qPh-2-1) controlles plant height on chromosome between marker P66M89315-P37M70169, the average contribution rate is 7.13%; QTL (qEh-3- 1) controlles ear height on chromosome 3 between marker P66M47273-umc1400, the average contribution rate is 19.49%; QTL (qEl-4-2) controlles ear length on chromosome 4 between marker umc1058-umc2289, the average contribution rate is 5.64% ; QTL (qEd-8-1) controlles ear diameter on chromosome 8 between marker bnlg240-umc1268, the average contribution rate is 7.99%.The stable expression QTL can be further used in molecular marker-assisted breeding. |
PDF Full Text Request