Study On Inheritance Of Main Index Of Quality And Agronomic And Physiologic Traits In Silage Maize (Zea May L.)

The objectives of this study were(1) to evaluate stover quality of 26 widely used silage corn inbred lines in Sichuan and to determine the stover quality contributing traits(2)to analyze genetic parameter, heterosis, correlation between parents and their F₁s for different silage stover quality traits of 5×21 NCâ…¡design with 26 lines as parents of 105 incomplete diallel crosses.(3) to analyze genetic parameter correlation of key index between agronomic and physiological traits in silage maize.(4) to determine the correlation of key index among quality,agronomic and physiological traits with 26 lines and 105 crosses in silage maize. The easy breeding index ofs were found, which had high yield, quality and drought tolerance traits in silage maize. The main results were as following:(1)The main stover quality traits of 26 silage materials were comprehensively evaluated in this study. The results showed that there were significant variations and the quality of IVDMD and its relative traits was in almost normal distribution. The good quality traits would have higher IVDMD, CP, EE and low ADF, NDF in silage corn inbred lines. Five elite inbred lines with high IVDMD, CP, EE and low ADF, NDF had been screened out. The path analysis showed there should be high CP and EE, low NDF, proper seed oil in order to having high IVDMD stover trait.(2) The stove quality traits genetic analysis of silage maize showed that the additive variances of those stover quality traits were obviously higher than dominant variance except of SYI. Their general combining ability(GCA) were more important than special combining ability(SCA). The heterosis performance of SYI,ADF and NDF showed positive heterosis over parent, IVDMD and EE showed negative heterosis over parent. The IVDMD in F1 was significantly negative correlated with difference of parents, and NDF was significantly negative correlated with difference of parents, and SYI was more significantly negative correlated with Low value parent. The lines with high IVDMD, CP, EE and low ADF, NDF should be selected as parents in quality silage maize breeding.(3) The agronomic traits analysis results showed that there should be a good cross with high stover yield, high seed yield, proper ear distance and low bald tip length in silage maize. Seven elite inbred lines had been screened out which could improve the yield of biology, stover and seed. Correlation analysis showed it could improve the yield of stover, seed and biology with positive directness choice of weight of 1000 kernels, Ear length and ear distance. The agronomic traits genetic analysis of silage maize showed that the dominant variances of those agronomic traits were obviously higher than additive variance except of total leaves and ear distance. Their special combining ability(SCA) were more important than general combining ability(GCA).(4) The correlation of main physiologic traits showed that the ear leaf Fv/Fm was closely related to leaf Fv, leaf Fm,leaf Fo, leaf Area, leaf SPAD, ear leaf Fv/Fm. Correlation analysis showed it could improve the drought tolerance and biology yield with positive direct choice of leaf Fm/Fm, positive indirect choice of leaf Fv and negative indirect choice of leaf Fo in silage crosse maize. Five elite inbred lines had been screened out which could improve five key index yield of drought tolerance. The physiologic traits genetic analysis of silage maize showed that the dominant variances of those main physiologic traits were obviously higher than additive variance except of leaf Fo and leaf Area. Their special combining ability(SCA) was more important than general combining ability(GCA).(5) Comprehensive evaluation showed that stover value was closely related to agronomic, quality and physiologic traits for 26 silage maize lines. Agronomic traits were closely related to plant height, ear distance and SYI, next to them was ear rows. Quality trait was closely related to stover IVDMD and stover CP, next to them was seed ST. Physiologic traits was closely related to leaf Fv/Fm and ear leaf SPAD, next to them was leaf Fo. Five elite silage maize inbred lines had been screened out which had comprehensive and excellent traits. The results also showed there was a few relative between quality and agronomic traits, but key indexes was not relative; there was a few relative between physiologic and agronomic traits; there was a few relative between physiologic and quality traits of stover, but it had little influence between physiologic and quality traits of seed in silage maize. And the auther put forward a primary principle on cross selection and screening of high biology yield, high drought-resistant and excellent quality traits in silage maize. First, there should have good quality traits with high IVDMD, CP, EE and low ADF, NDF; Secondly, there should be a good agronomic traits with high biology yield, high seed yield, enough plant height and proper ear distance and low bald tip length in silage maize. Finally, there also should have good physiologic traits with high leaf Area and leaf Fv/Fm, next to them were leaf SPAD.