Genetic Model Analysis Of Seed Vigor Related Traits In Waxy Corn

Corn is one of the worldwide main major food crop,which plays significant roles of the world's grain production.The quality of corn seed has a great influence on Maize production.High vigor seeds germinate rapidly,neatly and strongly and can resist all kinds of adverse environmental conditions.Otherwise,Low vigor seeds germinate abnormally to cause huge losses to agricultural production.In order to achieve high yield of corn,it has become the main research direction to breed new varieties with high seed vigor.Genetic segregation analysis for waxy corn seed vigor was evaluated based upon germination energy,electroconductibility and vigor index using major gene-polygene mixed inheritance models and joint analysis of P1,P2,F1,B1,B2 and F2 populations obtained from the cross combination N34×N56.The results were as follows:1.Genetic model E-0,with two major genes with additive-dominant-epistatic effects plus polygenes with additive-dominant-epistatic effects,was chosen as the best model for germination energy of the cross combination of N34×N56.From the estimation of the first-order genetic parameters(?da?>?db?),the additive effect of the first major gene was greater than that of the second major genes.According to the ratio of dominant and additive effects of two pairs of major genes(?ha/da?<1,?hb/db?<1),the dominant value of these two genes is smaller than the corresponding additive effect.The main gene of germination energe proved mainly additive effect.According to the two-order parameters,the heritability of germination potential is relatively high.Continuous selection of plants with high germination potential will be beneficial to increase the seed vigor of maize.Because the heritability of the major genes of the three segregating generations was higher than the corresponding polygenic heritability,The germination energe was dominated by the main gene.2.The inheritance of vigor index could be explained with models E-1(two major genes with additive-dominant-epistatic effects plus polygenes with additive-dominant effects).From the estimation of the first-order genetic parameters(?da?=?db?),the additive effect of the first major gene was equivalent to that of the second major genes.According to the ratio of dominant and additive effects of two pairs of major genes(?ha/da?<1,?hb/db?<1),the dominant value of these two genes is smaller than the corresponding additive effect.The main gene of vigor index proved mainly additive effect.According to the two-order parameters,the heritability of vigor index is relatively high.Continuous selection of plants with high seed vigor index will be beneficial to increase the seed vigor of maize.Because the heritability of the major genes of the three segregating generations was higher than the corresponding polygenic heritability,The vigor index was dominated by the main gene.3.The best genetic model for seed electroconductibility was D-1(one major gene with additive-dominant effects plus polygenes with additive-dominant).From the estimation of the first-order genetic parameters(d<0),favourable gene came from male parent N56.According to the ratio of dominant and additive effects of polygenes([h]/[d] =1),the dominant value of polygenes was equivalent to the corresponding additive effect.The heritability of seed electroconductibility is relatively high.Continuous selection of plants with high seed electroconductibility will be beneficial to increase the seed vigor of maize.Because the heritability of the major genes of the three segregating generations was higher than the corresponding polygenic heritability,The seed electroconductibility was dominated by the main gene.In this study,genetic segregation analysis for seed vigor traits in P1,P2,F1,B1,B2 and F2 generations was conducted using major gene-polygene mixed inheritance models and the joint analysis method.The aim was to explore the genetic law of waxy maize seed vigor related traits,and to provide theoretical basis for breeding practice.