Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/22/2005
Publication Date: 6/15/2006
Citation: Percy, R.G., Cantrell, R.G., Zhang, J. 2006. Genetic variation for agronomic and fiber properties in an introgressed recombinant inbred population of cotton. Crop Science, pp. 1311-1317. Interpretive Summary: There is a need to improve fiber quality in the predominant cotton species, Gossypium hirsutum (upland cotton) to meet the requirements of evolving industry processing and end uses. However, current commercial cultivars of upland cotton have restricted variability for fiber quality traits. Extra-long staple cottons (Gossypium barbadense) have superior fiber quality, but transfer of traits from extra-long staple cotton to upland cotton has been difficult and only partially successful. In this work, we created a population of lines from a cross of an upland cotton with a line possessing genetic variability from an extra-long staple cotton. Within this population are lines possessing superior fiber length, strength, and fineness. The inheritance of these traits is high, and their transfer to other lines should be easier than has been previously reported in direct crosses of upland and extra-long staple cottons. The population of lines will allow investigators to identify genes involved in fiber quality through genetic mapping and analyses. Identification of specific genes associated with fiber quality will make future breeding and improvement efforts more efficient.
Technical Abstract: Genetic variation available for the improvement of fiber properties is restricted in commercial upland cotton (Gossypium hirsutum L.). Resources for fiber improvement exist in G. barbadense, but introgression of traits has been a limited success. The objectives of this study were to investigate the genetic variation and heritability of agronomic and fiber traits within a diverse recombinant inbred line (RIL) population created using a stable introgressed parent. The population (n=98 lines) had as its parents NM24016, a stable G. hirsutum line with significant introgression from G. barbadense, and TM1, the G. hirsutum genetic standard. Yield, plant height, boll size, lint percent, and fiber length, strength, micronaire, and elongation were measured in randomized, complete block tests at Las Cruces, NM and Maricopa, AZ in 2001 and 2002. Genotype coefficients of variation (CV) were highest for plant height and boll size. Among fiber traits, fiber length and micronaire produced the highest genotype CVs. Most traits (fiber elongation excepted) exhibited high broadsense heritability; ranging from 0.69 for lint yield to 0.92 for 2.5% span length. Transgressive segregants were identified for most traits. Fiber strength and 2.5% span length were favorably correlated (r = 0.59, P = 0.001), as were 2.5% span length and micronaire (r = -0.47, P = 0.001). The NM24016/TM1 RIL population presents valuable genetic variation for fiber quality improvement efforts in G. hirsutum.