Early vigor of advanced breeding lines and modern cotton cultivars
Stand establishment and early vigor are critical to the successful production of cotton (Gossypium hirsutum L.). Rapid early growth could provide significant advantages to young plants relative to diseases, insects, and weeds. The objectives of this research were to identify traits that contribute to differences in early growth, characterize genotypic variation in early vigor among modern cultivars and advanced breeding lines, and determine the effect of the seed production environment on early vigor. Early growth of 10 genotypes from private companies and 18 unreleased breeding lines was compared through measurements of leaf area and biomass under field conditions in 2 yr. A positive correlation of seed weight and rapid early growth was observed up to 32 d after planting (DAP). Cotyledon area was positively associated with shoot dry weight over the course of the first 52 DAP. Significant genotypic differences were observed for cotyledon and total leaf areas, and for cotyledon, first true leaf, total leaf, stem, and total shoot dry weights in both years within approximately the first 4 wk after planting. No correlation between lint yield and rapid early growth was found. For the first 17 (2009) and 32 (2008) DAP—but not after that—plants grown from seeds produced in distinct environments differed in early vigor. Overall, seeds from breeding lines produced more vigorous seedlings than did seeds of commercial genotypes. Although heritability of the examined traits has not been established, the broad range in values and significant genotypic variation suggest that breeding for enhanced early vigor should be possible without compromising yield.
Environmental Plant Science and Natural Resources
Liu, S., M. Remley, F. M. Bourland, R. L. Nichols, W. E. Stevens, A. Phillips Jones, and F. B. Fritschi. "Early vigor of advanced breeding lines and modern cotton cultivars." Crop Science 55, no. 4 (2015): 1729-1740.