The Genetic Study Of Related Traits Suitable For Mechanizedharvest In Maize

The whole maize planting course will be mechanization, it is puzzle of maize planting at present that realizing mechanized harvesting maize kernel, Breeding Suitable for mechanized varieties is key factor. This study adopt 8 inbred line with many years of breeding as female parent, Using seven common inbred line as male parent, getting 56 hybridized combination according to NCII project. Using Zhengdan958 and Xianyu335 as contrast, Zhengdan958 and Xianyu335 have large planting area, but Zhengdan958 doesn’t suit mechanized harvesting maize kernel. This study analyze the feature of variety which suit mechanized harvesting kernel through research plant trait, Bracts traits, straw stiffness and the kernel moisture content of the hybridized combination. And studying the genetic regularity of mechanization harvest related traits. The main research results are as follows:1、The result of phenotypic traits variance analysis shows that different materials on each character have showed extremely significant difference, So there is a real genetic differences between explanatory material. This study found out 10 hybridized combination with excellent comprehensive characters, hybridized combination2, hybridized combination4, hybridized combination7, hybridized combination9, hybridized combination10, hybridized combination15, hybridized combination18, hybridized combination25, hybridized combination28 and hybridized combination29.2、This study found the rate of water loss from 86 days to 104 days after sprout in different hybridized combination has a significant difference. The contrast Zhengdan958 has a faster rate of water loss from 86 days to 92 days after sprout, then the rate of water loss slow down. The rate of water loss of Xianyu335 is relative stable from 86 days to 104 days after sprout, and always keep rapid dehydration rate. We divide the 56 hybridized combinations into three categories through compared with Zhengdan958 and Xianyu335: similar Zhengdan958, similar Xianyu335 and Dehydration faster hybridized combination. We find 3 excellent in comprehensive characteristic hybridized combinations, they are suit mechanized harvesting maize kernel. Hybridized combination4, hybridized combination15 and hybridized combination28.3、We find the length of bract and wide of bract have an effect on maize kernel moisture content. The length of bract has a greater influence on the maize kernel moisture content at harvest, reach to extremely significant level. It explains the kernel moisture content of Xianyu335 is low at harvest. In addition, we also found that the stem strength, hardness and plant height between three characters influence each other, and the stem strength also has effect on the kernel moisture content of different periods, and reached positive significant level. The ear height has a greater influence on maize kernel moisture content. So we have to study length of bract, stem strength and ear height to find a hybridized combination which is strong ability to resist lodging, dehydration rate fast and low kernel moisture content.4、In this study, we analyzed the combining ability of bract length, stem strength, hardness and grain moisture axis at different times, and found that the general combining ability between the various traits of the same parents and the same traits of each parent were significant differences. This result indicated that genetic additive effects was different for every parent in different traits. In addition, the study also found that different combinations of the same group with a parent or the same group of different traits, specific combining ability also significant differences, indicating that the gene interaction complexity. There is no causal relationship between the general combining ability effect of parent and specific combining ability of parent group with its combination. The Specific combining ability of the group with two parent of high general combining ability is not necessarily high. Similarly, The Specific combining ability of the group with two parent of low general combining ability may be high. In this sense, when equipped with the hybrids, extensive test cross is an integral part of the work. Only in understanding the characteristics of the parents on the basis of their extensive test cross, It is expected to get a strong advantage hybrids.5、On the heritability of each trait,bract length had a high broad heritability and narrow heritability, which was 82.28% and 62.78% respectively. This result indicated that this trait was mainly controlled by additive gene effects, can be selected in early generation. The broad heritability and narrow heritability for stalk strength was 77.54% and 23.29% respectively, indicating that stalk strength was affected by small additive effect impact. It can be seen that the genetic stability of stem intensity was poor, which should be selected in the high generation. In terms of grain moisture content, the heritability of 95 days after emergence was low, only for 28.54%. But the heritability for 98 days after emergence and 104 days after emergence was high, which was 66.8%�'� 54.03% respectively, indicating that grain moisture at 95 days after emergence was not stable in hereditary, and affected by high environmental impact, while close to harvest, grain moisture was impacted by high additive genetic effects. Our study also showed that shaft had a high broad heritability and narrow heritability, which was 61.84% and 40.34 respectively, indicating that shaft hardness was affected by small additive effect impact.