QTL Analysis Of Lodging Resistance Traits In Maize Population Of Maize

Maize(Zea mays L.) is one of the most important cereal crops and feed sources worldwide; however, maize yield has been influenced by lodging in recent years. To systematically investigate the genetic basis related to stalk lodging, IBM syn 10 DH population was used as the experimental materials in this study and the genetic architecture of lodging was investigated using phenotype of its association traits in different environments, such as rind penetrometer resistance (RPR)、stalk bending strength(SBS) and stalk diameter(SD). In addition, the high density genetic map was constructed to detect QTL loci of lodging-related traits. The results are as follows:1. RPR, SBS and SD showed the continuous variation characteristics with normal distribution basically, the results suggested that the lodging-relevant traits are typical quantitative traits, controlled by multiple genes; correlation analysis results showed that SBS were significant related to RPR and SD respectively, but the correlation of RPR and SD was not significantly; moreover, the variance analysis showed that there were significant differences between environment, family, as well as the interactions of environment and family for each related traits; the evaluated heritability were 74.99%> 51.70% and 69.90%, respectively.2. Three, three and three QTLs were detected for RPR in Chongzhou, Haerbin and Xishuangbanna, respectively, and their genetic contribution of each QTLs ranged from 5.63% to 8.30%, interestingly, and one QTL was detected in different environments located on chromosome 1 from 45.92 to 49.9 cM; Meanwhile, six QTLs were detected for RPR by the BLUP prediction data, the genetic contribution of each QTLs ranged from 4.96% to 8.41%, four QTLs were detected in the same position under three different environments.3. Two, four and three QTLs were detected for SBS in three different environments, respectively, and the genetic contribution of each QTL ranged from 5.67% to 10.19%, one QTL (qHSBS1-2) was detected on chromosome 1 from 126.35 to 128.17cM, with 10.19% of the genetic contribution, we demonstrated that it might be a major QTL controlling RPR in this interval; Moreover, two QTLs were detected for SBS using the BLUP prediction data, the genetic contribution of each QTL were 7.11% and 8.19% respectively.4. Four, five and five QTLs were detected for SD in three different environments, respectively, and the genetic contribution of each QTL ranged from 5.42% to 17.69%. Moreover, one QTL with 17.69% genetic contribution, distributed on chromosome 8 from 96.37 to 103.63 cM can be detected in different environments, which might exist a major QTL controlling SD in this interval; In addition, six QTLs were detected for SD by the BLUP prediction data, the genetic contribution of each QTL from 4.79% to 10.25% respectively, and four QTLs can be detected in the same position under three different environments.5. Interestingly, different QTLs controlling for SBS and SD were detected in the same position, which is ranging from 122.03 to 128.17cM on chromosome 1 and from 95.61 to 103.63cM on chromosome 8, respectively. Which might be significate QTLs controlling both SBS and SD in this interval.6. Based on the available annotation of the B73 reference sequence, and combined with the related molecular biology information, there are 16 candidate genes related to lodging resistance in the major QTLs interval region.