Genetic Analysis Of Several Stalk Traits In Mazie

Corn stalk characters (plant height, car height, stem diameter) is one of the most important traits of plant type, it affects yield, photosynthetic characteristics, lodging resistance and disease resistance significantly. Some genetic researches were developed for the3characters in order to investigate the genetic basic. Inheritance of plant height, ear height, stem diameter of10sets of material (18white×1212,Rp125×1212)were detected by applying major gene plus polygene inheritance model combined with multiple generations segregation analysis in6generations (P1, F1, P2, F2, B1, B2); Furtherly using composite interval mapping methodthe to detecte QTLs of plant height, ear height, stem diameter with F2group data at Sichuan and Yunnan, which derived from B73×1212. The results are as follows:1、Genetic model examination showed:①The characters of plant height:3sets of materials were fitted to additive-dominance-epistasis polygenes model (C),1sets of materials was fitted to one additive major gene plus additive-dominance polygenes model (D-2),4sets of materials were fitted to two additive-dominance-epistasis major genes plus additive-dominance-epistasis polygenes model (E),2sets of materials were fitted to two additive-dominance-epistasis major genes plus additive-dominance polygenes model (E-1).②The characters of plant height,6sets of materials were fitted to additive-dominance-epistasis polygenes model (C),1sets of materials was fitted to one additive-dominance major gene plus additive-dominance-epistasis polygenes model (D).2sets of materials were fitted to two additive-dominance-epistasis major genes plus additive-dominance-epistasis polygenes model (E),1sets of materials was fitted to two additive major genes plus additive-dominance polygenes model (E-3).③The characters of stem diameter,3sets of materials were fitted to additive-dominance-epistasis polygenes model (C),1sets of materials was fitted to one additive major gene plus additive-dominance polygenes model (D-2),1sets of materials was fitted to one complete dominant gene plus additive-dominance polygenes model (D-3),1sets of materials was fitted to two additive-dominance-epistasis major genes plus additive-dominance polygenes model (E-1). 2、Genetic parameter analysis showed:Heritability of major genes plus polygenes was above80%, It indicated that trait was mainly determined by genetic factors which guide us should select in early generation to improve breeding efficiency.3、A genetic linkage map containing115SSR markers was constructed, which covered the10chromosomes of Maize with1430cM totally and an average of12.54cM.4、9QTLs of plant height were detected,in which6at Sichuan,3at Yunnan, none consensus QTL was detected at the two places; the contribution to phenotypic showed that the top two were10.7%and10.4%,the other QTLs varied from5.4%～9.8%; gene’s action way showed, QTLs had additive effect,3QTLs had partial dominance effect,4QTLs had over dominance.5、17QTLs of ear height were detected, in which11at Sichuan,6at Yunnan,3consensus QTLs was detected at the two place; the contribution to phenotypic showed that the top two were10.6%and10.2%which detected at Sichuan, the other QTLs varied from3.3%～8.8%, the top two were15.5%and10.6%which detected at Yunnan, the other QTLs varied from4.9%～8.3%; gene’s action way showed,2QTLs had additive effect,11QTLs had partial dominance effect,2QTLs had dominance,2QTLs had over dominance, that showed ear height was mainly affected by partial dominance effect.6、7QTLs of stem diameter were detected,in which3at Sichuan,4at Yunnan, none consensus QTL was detected at the two places; the contribution to phenotypic showed, the top one was12.1%, the other QTLs varied from5.3%～9.7%, gene’s action way showed,1QTL had additive effect,1QTL had partial dominance effect,1QTL had dominance,4QTLs had over dominance, that showed stem diameter was mainly affected by over dominance7、2marker intervals were detected which containing plant height and ear height QTLs,1marker interval were detected which containing plant height and stem diameter QTLs;1marker interval were detected which containing ear height and stem diameter QTLs;1marker interval were detected which containing plant height, ear height and stem diameter QTLs. 8、By comparison, the results were relatively consistent between segregation analysis method and QTL positioning method, both two had superiority and defect, they could be confirmed and supplemented by each other.