Genotypic and phenotypic relationships ol lint yield, fibre properties and seed content in a cross of two cotton genotypes

摘要

The breeding and production of cotton have traditionally been guided by considerations of fibre yield and quality (Kohel, 1998). Improvements in textile processing, particularly advances in spinning technology, have led to increased emphasis on breeding cotton for both improved yield and improved fibre properties (Green & Gulp, 1990; Bradow & Davi-donis, 2000). Cottonseed products, oil and protein, are an important secondary product. There is mounting interest in cottonseed quality due to the world'sdemand for food. This interest should stimulate research needed on several aspects of cotton seed quality. From studies with cottonseed, it is clear that the composition of oil and protein can be affected by factors such as cultivars, location, year, and their interactions (Turner et al., 1976a; Cherry et al., 1981; Kohel & Cherry, 1983; Kloth, 1998). The composition of oil and protein can also be associated with yield and fibre quality (Turner et al., 1976b; Sun et al., 1987; Schenek, 1988; Dani, 1989; Xia et al, 1989; Dani, 1991; Taneja et al., 1993; Gururajan et al., 1992). Wu (1990) reported that relationships of oil and protein content to fibre yield and quality were significantly positive in the Gossypium hirsutum variety Xinluzao 3. In contrast, some studies have shown that correlations between oil/protein content and fibre quality traits were not significant (Dani, 1991; Zhou et al., 1992). In addition, Turner et al. (1976b) found no significant correlations between yield and oil content or yield and protein content. However, Xia et al. (1989) reported that selection for longer and stronger fibres was possible among the low oil content varieties, indicating that a negative correlation exists between oil content and fibre quality. Clearly, there is a lack' of consistency in the associations found in the literature. From a breeding and agronomic viewpoint, it is important that these relationships between seed characteristics and yield or fibre properties are well understood. The objective ofthis study was to ascertain the genotypic and phenotypic relationships between seed content and lint yield and fibre properties from a single cross of two cotton genotypes.