Studies On Biochemical Mechanism And Genetic Analysis Of Earliness But Not Decrepitude Of The Shorted-season Upland Cotton

A partial-diallel genetic design consisting 10 pure lines and their 5 positive cross FI and 5 negative cross FI, and 10 F2 populations were grown at the same field in Chinese Cotton Research Institute in 2001 and 2002. The experimental design was a randomized complete-block with three replications. The objectives of this study were (i) to illustrate the biochemical genetic mechanism in the earliness-but-not-decrepitude varieties (ii) to understand the inheritance of earliness and the main economic characters of the short season upland cotton.The results showed that anti-oxidant enzymes (such as CAT, POD, and SOD) activity, MDA, IAA and ABA contents etc. biochemical traits had an authoritative normal distribution, so they were typically quantitative character.The cytoplasmic and maternal effects plays an important role on anti-oxidant enzymes activity and its relative activity, MDA, IAA and ABA contents, and chlorophyll a, b, a+b, and a/b when analysis by ADM model; With the ADAA model, the additive X additive epistasis effects were also detected on the same biochemical index, such as SOD activity, MDA contents, CAT and POD activity etc. The dominant and additive effects were the most important genetic effects on lint yield, lint percentage, lint index and some earliness traits, such as the plant growing period(PGP), Date of first square(DFS), Date of first flower(DFF), Date of first open boll(DFOB) and Boll maturation period(BMP).The dominant X environment effects was discovered on the lint percentage before frost.