Physiological Mechanisms Of Grain Yield Increasing In Cytoplasmic Male Sterile Maize

Male sterile characteristic plays an important rule in the utilization of heterosis, which can save nutrition and increase grain yield. In order to elucidate the mechanism in cytoplasmic male sterile maize of improving yield, the experiment takes two inbred lines of abroad application in practice and its homotype fertile material as trial materials, and analysis the differences of photosynthetic traits, mineral nutrition and root characteristic between the two inbred lines,then the response to nitrogen deficiency of grain yield and quality in CMS maize was studied compared with its maintainer. The principal results were as follows:1 Grain yield and characters of matter accumulation in cytoplasmic male sterility (CMS) maizeGrain yield of CMS maize was about 11.5% higher than that of male fertile maize significantly, and the increment reach about 13% and 10% at N deficiency and normal N application conditions respectively. On the other hand, 1000-kernel weight and harvest index of CMS was higher greatly than those of MF (male fertile) maize, but kernel number of era was not different significantly. Grain filling rate was decreased as kernel developed. Grain filling rate of male fertile decreased at N deficiency conditions while that of CMS increased evidently.Dry weight of CMS was higher than that of MF after anthesis, and differences existed in dry matter partition at different positions and periods.