Inheritance Of Quality Traits Of Maize Kernels And Stalks With Difference Genotypes And Their Relations With Environments

Based on the analysis of the grain quality of 192 maize inbred lines,ten inbreds from 5 heterotic groups were choosedas parents, according to the relative difference on protein content in kernel, to compose a total of 90 positive and negative hybrid combinations according to Griffing diallel cross design. The crosses were growen in 3 locations of Nanyang, Zhengzhou and Xunxian in Henan Province.The content of crude protein, starch, fat, lysine in kernels and the crude protein, crude fat, acid detergent fiber (ADF), neutral detergent fiber (NDF) content in stalks were analyzed by use of near-infrared analysis technology, at the same time the main agronomic traits were evaluated, and the analysis also had been made on the genetic effects of grain and straw quality traits of hybrids with different genetic background , the heterosis, genotypes, environments as well as their interaction effects on quality traits and the some major agronomic traits.The results showed that:1) the nutrient contents in kernel varied with inbred lines, the inbred lines 8085 and E28 are higher in protein and lysine contents, but lower in starch content, so they are suitable for being as materials in high - protein breeding. Zheng 58 and Dan 340 with high starch , low protein and lysine content, fit for as the high-starch breeding material; while the inbreds 8085 and Xu178 have higher fat content , preferably as the high-oil breeding parental material.2) the nutrient contents in straw also varied with inbreds.The average content of crude protein, crude fat, ADF, NDF in parental straw is 5.28 %, 3.31 %, 45.07 %, 67.49 % and 2.67 %, respectively, the changing range is 2.67%~ 8.12%, 2.65% ~ 4.19%, 41.29% ~ 54.75 % and 74.15% ~ 59.84% ,respectively. The inbred lines K12 with higher protein and fat content, lower ADF and NDF content, is favorable to be as a parent of hybrid to improve the straw quality ; while the 330 inbred line with higher ADF and NDF content, and lower protein and fat content,is disadvantage to improve the straw quality of hybrid.3) the gene actions controlling the quality traits of grain and straw are mainly additive effect; the broad-sense heritability and narrow sense heritability of grain protein, fat, starch,and lysine are 38.71% and 30.19%, 17.5% and 15.5%, 14.82% and 13.4%, 15.59% and 11.93% respectively; while the broad-sense heritability and narrow sense heritability of straw protein, fat, ADF, NDF are 8.11% and 4.72%, 15.53% and 1.5%, 42.12% and 13.39%, 11.33% and 7.52%, although the heritability of these traits are not high and easy to be effected by environments, the protein content in kernel is less comparatively effecetd by environments than other traits, which establish the genetic basis for the high-protein breeding .4) The quality traits of hybrids is significantly affected by genotypes, environments and their interaction , view from the point of grain protein content, Henan Province has a trend of increasing from south to north, while the straw protein content has a trend of increasing from north to south..5) The parents with high general combining ability(GCA)in some traits , may hvae not the high specific combining ability(SCA) in the same traits. Such as inbred lines 2 and 3 both with higher GCA in grain protein content, while the cross 2×3 with lower SCA,on the contrary ,the crosses 2×6,7×9,1×8 performed higher SCA, same performance happened on other traits. which infered that the GCA of grain and straw quality traits may not certainly have corrrelation with SCA.6) out of the 4 grain quality traits, protein, lysine and fat content all have negative heterosis, but the starch content of all crosses perform positive heterosis,and the heterosis varies with crosses.While out of the 4 straw quality traits, 71.11% crosses performed over mid-parents heterosis in straw crude protein content, 22.22% crosses over-high-parent heterosis, with the obvious positive heterosis. The fat content of all crosses performed negative heterosis; ADF content with a certain positive advantage; and NDF content with more positive heterosis. Therefore, in order to increase the protein content of straw and digestibility, hybrids should be maintained under the premise of lodging resistance, and the parent,probably with more higher protein content and lower cellulose content ,shoud be choosen to improve the quality of hybrids.7) The results of this study show that the grain yield has no significant correlation with protein ,starch and fat contents in kernel, indicating that it is feasible to improve the maize yield and quality in kernel simultaneously through pyramiding elite genes, but it must be more difficult than to improve a single trait.