Analysis Of Combining Ability And Inheritance Of Elite Maize Inbred Lines From Different Groups

Ninety crosses were made using ten inbred lines selected from five heterosis groups, Tangsipingtou,Lancast,Reid,Lvdahonggu and the tropic germplasm,according to Griffing design in winter of 2004.The ninety F1 crosses were planted in complete block design with two replications in Xunxian in summer of 2005 and 2006 separately,Calculating the date between the genotypes,years and genotype by year interactions by the statistical analysis method.Analyzed the influence on the Agronomic Characters of F1 generation;Through the combining ability variance analysis,estimated the agronomic characters genetic effect.The results showed that:(1)Highly remarkable difference existed among the genotypes on all characters identified, and the genotype×year interaction effects reached remarkable or the extremely remarkable levels on all characters except ear height,ear length,cob diameter and kernel ratio.The variance of general combining ability(GCA)of all surveyed characters were significant difference,while the variance of special combining ability(SCA)of all surveyed characters reached significant levels except cob diameter,kernel ratio.In the reciprocal effects only the row number per ear,length of bare top,ear diameter characters reached significant difference levels others were not.(2)The effects of GCA on different inbred lines were different,such as kernel weight,ear diameter,length of bare top,kernel number per row,1000 kernel weight and cob diameter of inbred 4 were most high in effects of GCA.Plant height,ear height and dry ear weight of inbred 2 were most high in effects of GCA.Ear length and kernel number per row of inbred 5 were most high in effects of GCA.The effect of row number per ear of inbred 7 reached highest.Kernel ratio of inbred 6 reached highest.(3)The effects of SCA varied with inbred lines in each characters.In this study,only a few crosses reached remarkable or extremely remarkable levels in SCA,which took took about 4.44%-35.56%among the 45 crosses.Among those,the cross 4×9 on kernel weight and 1000 kernel weight,6×7 on ear lengths and ear diameter,2×7 on dry ear weight,2×10 on kernel number per row, 4×8 on row number per ear,1×6 on ear height,7×10 on plant height and so on all reached highest.The number of crosses reached remarkable or extremely remarkable level in the reciprocal effects were only rare,just arisen more in row number per ear.(4)The heredity in broad sense(h~2_B)of kernel rate was lower,while that of other 9 characters were higher above 50 percent,while the heredity in narrow sense(h~2_N)were different,for example the h~2_N of rows per ear was the highest(94.859%),followed by 1000 kernel weight,that of kernel weight and ear weight were about 20 percent.The h~2_N of others ear characters varied from 30-50%.The results showed that the additive effects of rows per ear and weight of 1000 kernels were important,the inadditive effect of kernel weight and ear weight were important,the additive effect and the inadditive effect were both important in the other ear characters.(5)The yield of crosses diversity largely,the same cross appeared different yields with years,crosses 9×4,2×1,4×3,4×8,10×2,3×6 showed higher than others,The mean yield in each block was 2.50 kg,2.38 kg,2.35 kg,2.33 kg,2.32 kg,2.29 kg,respectively.(6)The 15 high yield crosses were made by Reid×Tansipingtou,Reid×Tropic germplasm,Lvdahonggu×Tansipingtou,Tansipingtou×Tropic germplasm,Tropic germplasm×Lancast,Lvdahonggu×Tropic germplasm etc.