Inheritance Of Stover Quality Traits And Their Determination By Near-infrared Reflectance Spectroscopy (NIRS) In Silage Maize (Zea May L.)

The objectives of this study were (1) to investigate the feasibility and methods of measuring quality of air-dried and ensiled stover quality of silage maize with near infrared reflectance spectroscopy (NIRS) with selected 165 from 900 air-dried samples and 150 from 675 ensiled samples of two years. (2) to evaluate stover quality of 102 widely used normal oil corn(NOC)and high oil corn (HOC)inbred lines in china and to determine the stover quality contributing traits (3)to analyze genetic parameter, heterosis, correlation between parents and their F₁S for different silage stover quality traits in two sets of 5×10 NC â…¡ design with 10 HOC and 10 NOC lines as parents, in which 5 HOC and 5 NOC lines were used as common parents of two sets of 50 incomplete diallel crosses. (4) to compare stover quality traits of different cross patterns in the crosses above-mentioned (HOC×HOC, HOC×NOC and NOC×NOC) and determine the characters of air-dried and ensiled stover quality and to explore the best silage maize cross patterns. (5) to evaluate the environment effect on the yield and stover quality performance at three cross patterns, analyze the stability of yield and quality, and to find the relationship among stover quality with kernel quality, yield and agronomic traits. The main results were as following:(1)The calibration models, IVDMD, NDF, ADF, CP, EE and WSC content in different air-dried maize stover and IVDMD, ADF, CP, EE, NDF in different ensiled whole plant and stover of maize, were established by using the techniques based on the principle component space of spectra , near infrared reflectance spectroscopy (NIRS) and partial least square regression (PLS). The models were tested by using cross and external validation. The established calibration models shows good in adaptability and stability. These calibration models can meet the need for quick analysis of air-dried and ensiled stover quality by external validation. These results had very important application and perspective in livestock industry and in screening and screening and evaluating quality components of silage maize breeding(2)The main stover quality traits of 102 NOC and HOC 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 quality traits of IVDMD and WSC of HOC (high oil corn) inbred lines were higher than those of NOC (normal oil corn) inbred lines, and ADF, ADL and NDF were lower than those of NOC. Five elite inbred lines with high IVDMD, WSC and low ADF. NDF and ADL had been screened out. The principal component analysis of stover quality traits showed that ADF, IVDMD, NDF and WSC content were the main factors influencing stover quality traits.(3) 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. The general combining ability (GCA) was more important than special combining ability (SCA). The heterosis performance of ADF, NDF showed positive heterosis over parent, EE showed positive heterosis over parent only in HOC×HOC cross pattern, and the rest of the quality traits showed negative heterosis over parent in three cross patterns(HOC×HOC, NOC×HOC and NOC×NOC). The IVDMD, WSC and CP in F1 wassignificantly positively correlated with mid-parent and high parent values, and ADF, NDF was significantly positively correlated with mid-parent and low parent values. The lines with high IVDMD, WSC, CP and low ADF, NDF should be selected as parents in quality silage maize breeding. The patterns of HOCxHOC or NOCxHOC was the best.(4)The three cross patterns between NOC and HOC and air-dried, ensiled treatments had obvious influence on maize stover quality. The difference of mean effect of IVDMD, EE, NDF and ADF was significant in air-dried and ensiled samples at three cross patterns. Compared to air-dried treatment, ensiled treatment increased IVDMD and EE content greatly and decreased the NDF and CP content, and had no obvious affect on ADF content. IVDMD and EE content of HOCxHOC cross pattern was the highest and those of NOCxNOC cross pattern was the lowest while ADF and NDF content of NOCxNOC cross pattern was the highest and those of HOCxHOC cross pattern was the lowest under air-dried and ensiled treatments. The result showed that the maize stover quality can be improved by the cross patterns of using the HOC line in silage maize breeding.(5) Environment factors and cross patterns had significant affection on yield and stover quality traits of silage maize. There were significant differences in yield and stover quality traits at different environments. NOCxNOC was the best and HOCxHOC was the worst in stover, grain and biomass yield. HOCxHOC was the highest and NOCXNOC was the lowest in IVDMD and WSC content of stover. While NOCxNOC was the highest and HOCxHOC was the lowest in NDF and ADF content of stover. IVDMD showed significant negative correlation with NDF, ADF, and significant positive correlation with WSC, while no obvious correlation with grain, stover and biomass yield, which showed that IVMD was subjected to ADF, NDF and WSC content and had little influence in stove, grain and biomass yield.