Stem Quality Analysis Of New ’Early Sowing And Early Maturing Type’ Wheat Varieties (Lines) In Sichuan

Wheat is one of the most widely grown food crops in China and the Sichuan basin is one of the main wheat producing areas in China.The group has developed new wheat varieties(lines)of ‘early sowing and early maturing type’ for the heat conditions in the Sichuan basin,where three matures are not enough and two matures are more than enough.This type of wheat can be sown earlier than traditional wheat in Sichuan,making full use of the light,heat and water resources available during the idle period of the land in October,and retaining the traditional wheat’s need to mature early to avoid forced maturation by high temperatures,allowing for higher yields.This type of wheat has been studied because of its early sowing,relatively long reproductive period,large ears and high grain size,accompanied by increased tillering and changes in plant height,and in the high humidity production environment of the Sichuan basin,which requires higher stem quality,so it is important to study its stem quality and analysis the factors influencing stem quality for its large-scale production.In this experiment,114 new ‘early sowing and early maturing type’wheat varieties(lines)in the Sichuan basin were selected by our group,the basal internode folding resistance(stem quality),stem morphological indicators and yield traits of each variety(line)were measured,and correlation analyses were carried out for each trait,and the lines with better overall performance in terms of stem quality and yield were selected using the subordinate function value method.The main results obtained were as follows:(1)There was a highly significant positive correlation between the second internode fracture resistance and the second internode fullness,solidity and wall thickness,with correlation coefficients of 0.415,0.334 and 0.516 respectively;and a highly significant positive correlation between the third internode fracture resistance and the third internode fresh weight,external diameter and fullness,with correlation coefficients of 0.491,0.300 and 0.413 respectively.It indicates that the heavier the wheat stem is,the more dry matter is accumulated,which can effectively improve the stem quality of wheat;the more fullness and solidity of the stem,the higher the density of the internal filling of the stem and the weight of the stalk.The increase of these parameters provides more robustness and load-bearing capacity to the stems of wheat plants,enabling them to better resist the influence of external environment and provide better stability and support.(2)Fracture resistance at the second internode was significantly and positively correlated with spike length,grain weight and number of grains per spike with correlation coefficients of 0.407,0.186 and 0.205 respectively.High stem quality indicates better mechanical strength and stability of the stem,which can effectively ensure the stem’s ability to support the upper weight,thus promoting the stability and growth of wheat yield per plant.In addition,the positive correlation between stem quality and wheat yield traits also indicates that stem quality and yield traits can be developed synergistically,thus providing a useful reference for wheat breeding and cultivation management.(3)Multiple stepwise regression analysis was carried out on the traits significantly related to stem quality,and it was found that the main factors affecting stem quality were the wall thickness of the second internode at the base,the fullness of the third internode at the base and the fresh weight of the stem.The main factors affecting stem quality and yield traits were used as evaluation criteria,and the membership function comprehensive evaluation method was used to select the top 5 wheat materials with good performance in stem quality and yield,which were No.10,No.11,No.78,No.4 and No.8.In conclusion,factors such as fresh weight,dry weight,fullness,firmness and wall thickness of the second and third internode at the base have an impact on stem quality.Among these factors,wall thickness of the second internode at the base,fullness of the third internode at the base and fresh weight of the stem are the main influencing factors on stem quality.In addition,stem quality was positively correlated with ear length,grain weight,grain number per ear and yield per plant,indicating that stem quality had an important effect on yield stability and growth of wheat.Five wheat materials with good stem quality and high yield were selected by membership function comprehensive evaluation method,which could provide useful reference for wheat breeding and cultivation management.