[Major-polygene effect analysis of super quality fiber properties in upland cotton (G. hirsutum L.)].

The modern textile industry depends on the improvement of fiber quality, especially strength to meet the needs of higher spinning speed. Inheritance of super quality fiber properties in Upland cotton was conducted in the present paper. P1, P2, F1, B1, B2 and F2 of eight crosses from five parents with different fiber strength, i.e. 7235 x TM1, TM1 x 7235, HS42 x TM1, PD69 x TM1, MD51 x TM1, 7235 x HS42, 7235 x PD69 and HS42 x PD69, and F2:3 for 7235 x TM1, were used in the study. The materials were planted in Nanjing or Hainan in 1998 and 1999, the individual plant fiber samples were tested with HVI system in Cotton Research Institute of CAAS at Anyang. The segregation analysis methods for major genes plus polygene mixed inheritance model developed by Gai were used to identify the genetic system of fiber qualities. The results from joint analyses of multiple segregating generations as well as single segregating generations, especially for F2:3, showed one major gene plus polygene mixed inheritance model in all fiber quality characters. The heritability values of major gene in F2 of 7235 x TM1 with great parent difference were estimated as 19.6% for fiber strength, 32.0% for micronaire and 13.9% for fiber length, but little in B1 and B2 for fiber qualities. The fiber length showed high and positive dominant effect, but negative value or zero of major or polygene dominant effects for other fiber qualities. Therefore, Mid-parent value or tendency to lower parent in F1 for most of fiber qualities lead to low selection efficiency, which suggests that molecular assisted selection should be considered at first in the improvement of fiber qualities.