Effects of different ecological environments on main agronomic traits of F_2 generation in Upland cotton (G. hirsutum L.)

Variation coefficient,correlation,path and regression for the main agronomic traits were analyzed using F2 generation of upland cotton(G.hirsutum L.) in Yellow River Valley cotton area(Xinxiang,Henan,environment I) and Northwest Inland cotton area(Shihezi,Xinjiang,environment II).The results were as follows: In two environments,variation coefficient of lint yield and bolls per plant were always the largest,growth period was always the smallest,and there existed bigger difference on boll weight,seed index and lint percentage.Correlations of the various environmental traits were not consistent.Correlations between bolls per plant and lint percentage、lint index、seed index,lint percentage and lint index,lint yield and initial node height、lint percentage、seed index showed distinct differences related to positive and negative.In two environments,Correlation coefficients and direct path coefficients between plant height、fruit branches、bolls per plant、boll weight and lint yield were all positive,so selecting these traits directly was effective;the ones between lint percentage and lint yield in environment Ⅱ were all negative,but a large role could be played in promoting lint yield via lint index;and the ones of some traits in two environments were all negative,their selection should be controlled within a certain range.Regression analysis further defined that plant height,bolls per plant and lint index took a significant impact on lint yield in environment I while growth period,fruit branches,bolls per plant and boll weight in environment Ⅱ,which defined the main direction of ecological shuttle breeding of cotton yield.