Study On The Key Technology Of Maize Double Haploid Breeding And Genetic Analysis Of DH Lines

Maize haploid breeding technology has become one of the important breeding techniques in domestic and overseas research institutes and breeding institutions. However, the haploid induction rate is low, technology is not mature and double technology limit its scale of factory. Therefore solving the problem of induction rate and double rate, becomes the key to maize haploid breeding technology.Based on this, this paper studied the induction and double of the new breeding induction lines, and genetic analysis of the new DH lines.This study includes three aspects. Firstly, using Dom group, No Reid group equipping hybrids and different taxa backbone inbred line as female parent material, cross with new inducetion lines of JS6-S1, JS6-S2, JS6-2, JS6-A1, JS6-A2 and JS6-A3 to hybrid induction of female parent, it was our’s job to study the induced effect ofthe new induction lines. Secondly, under 3 kinds of cultivation methods which were direct seeding, 2-3 leaf stage of transplanting seedling and 4-6 leaf stage of transplanting, it was our’s study to analys the influence under the three kinds of cultivation methods of haploid plants survival rate and pollination success rate. Thirdly, with the new breeding DH lines of 4DH51, 4DH60, 4DH63, 4DH67 and 4DH99 as male parent,it was important for us to choose Reid group, No Reid group, Dom group of six backbone-inbred lines as female parent, equipping diallel cross and research heterosis and combining ability of DH. Results showed that:1. Research the effect of the induce line. Research shows that: JS6- 2 induced the hybrid and inbred lines of induction rate average were8.40% and 8.39% respectively, the induced effect is good, has a certain application value. JS6- S2 and JS6- A1 induced the hybrid and inbred lines of induction rate average were7.43%, 6.39% and 7.86%, 6.28%respectively, the induced effect also is better. In addition, contrast Stock6, induced the hybrid and inbred lines of induction rate average were 1.21% and 0.98% respectively. So the new breeding haploid induce lines were significantly better than Stock6.2. Different induction rate showed on different induce lines induced different maternal genotype material, using the haploid breeding, can choose according to different material corresponding induction rate higher induce lines, in order to gain more maize haploid kernels, improve the efficiency of the haploid breeding.3. Research the effect of the planting mode on survival and pollination success rate. Research shows that: 2-3 leaf stage of transplanting average seedling survival rate was the average was 81.70%, 4-6 leaf stage of transplanting average seedling survival rate was 79.12%,and the lowest survival rate was direct transplanting haploid, for an average of 72.47%, the experimental study showed that seedling transplanting the treated haploid could improve the survival. Significant difference between the survival rates of different genetic basis, 2-3 leaf stage transplanting and 4-6 leaf stage transplanting the haploid pollination success rate wrer high, for an average of 11.34% and 11.33%, the lowest pollination success rate was direct transplanting haploid, for an average of 10.30%, no significant difference between haploid pollination success rates between different genetic bases. Indicates the seedling transplanting, can effectively enhance the survival rate of haploid plants of the field, to improve the solid number.4. Genetic analysis of DH lines. Research showed that: the main agronomic traits such as plant height heterosis performance were different with the five DH lines. The general combining ability analysis showed that: 4DH51 for breeding higher per plant yield, shorter ears and plant height, ear thicker, thinner lighter cob hybrid has important application value. 4DH60 for breeding heavier higher yield per plant, longer ear, and thinner cob hybrid has important application value. 4DH63 for breeding shorter ears height hybrid has important application value. 4DH67 for breeding heavier panicle weight, higher per plant yield, shorter plant height, longer ear and more rows hybrid has important application value. 4DH99 of breeding longer ear, shorter ears and plant height, thinner lighter cob has important application value. Special combining ability effect of per plant yield analysis showed that, there are 15 hybrids special combining ability of the combination of positive,(Dom × No Reid) and Reid, No Reid and Dom heterosis pattern consisting of combination number 5/15, 5/15 and 4/15 respectively. The result Shows that the DH lines breeding by the haploid breeding technology has good hybrid heterosis.