Abstract:

The ADM developmental genetic model containing environmental interaction was used to study the relationship of single boll weight at different developmental stages and developmental characteristics with yield and quality for island cotton parents and F₁ generations in three years. Selecting single boll weight at different developmental stages had a better effect on the selection of final single boll weight and fiber quality traits in island cotton. When the single boll weed heavy, the number of invalid bolls were reduced and lint in the early stage (10, 20 d), while increased in the later stage (60, 70 d). In the medium term (30, 40, 50 d), the boll weight had a certain selection effect on the final yield per plant. At cotton boll volume expansion period (0-10 d, 10-20 d), the net increment was larger, single boll weight increased, other yield traits decreased, and quality traits such as fiber length, reflectivity and yellowness were improved. At cotton boll filling period (30-40, 40-50, 60-70 d), the boll dry weight increased, main fiber quality traits became worse. The yield per plant was increased by selecting materials with boll weight fast increasing in the growth period later. In the process of boll formation, assimilates entered cotton boll earlier and boll volume increased slowly, so that the fiber matured gradually, forming good quality. The fiber development was obviously affected by maternal effect; therefore, it is important to select suitable maternal parents for improving fiber quality traits.

Key words: island cotton, boll weight, developmental heredity, developmental characteristics, genetic correlation