Submitted to: Crop Science
Publication Type: Germplasm Release
Publication Acceptance Date: September 30, 2000
Publication Date: January 1, 2001
Citation: PERCY, R.G. REGISTRATION OF PS-6NE- PS-6L(0), PS-6NEL(0), P62NE, P62L(0), AND P62NEL(0)EXTRA-LONG STAPLE COTTON GERMPLASM. CROP SCIENCE 41. 2001. 602-603 Interpretive Summary: Cotton production costs and environmental impacts can be reduced through the incorporation of insect resistance traits into earlier maturing cotton cultivars. Two traits that confer partial resistance to two insect pests and earlier plant maturity have been incorporated into Pima cotton. The okra-leaf trait, which modifies the shape of the cotton leaf, confers earlier maturity to the plant and partial resistance to the silverleaf whitefly. The nectariless trait removes organs from the cotton leaf and boll that secrete sugars and serve as feeding sites for insect pests. The nectariless trait confers partial resistance to the pink bollworm. These two traits have been incorporated singly and in combination into two Pima cotton lines. The resulting six cotton lines have been evaluated for their agronomic potential. The okra-leaf lines were found to be significantly earlier than their normal leaf counterparts. Fiber properties of the okra- -leaf, nectariless, or okra-leaf - nectariless Pima lines conform to the extra-long staple fiber properties required in Pima cotton. Six okra-leaf, nectariless, or okra-leaf - nectariless Pima lines have been released to public and private breeders for use in cotton improvement efforts.
Technical Abstract: The okra-leaf trait (Lo) confers earlier crop maturity in cotton and partial resistance to the silverleaf whitefly. The nectariless trait (ne) confers a partial resistance to the pink bollworm. These traits have been released in two Pima backgrounds for use by public and private breeders in cotton improvement efforts. The two traits were transferred into the cultivar Pima S-6 and into an early maturing line, P62, through backcrossing accompanied by selection. Yield, earliness of maturity, and fiber traits of 6 germplasm lines were measured in replicated tests in AZ in 1998. At the low desert Maricopa location where significant heat stress occurred, PS-6neLo produced 216 kg ha-1 more lint than PS-6. All okra-leaf and okra-leaf - nectariless lines were earlier maturing than their normal leaf parents. The line P62neLo matured 58% of its total yield 162 d after planting - an increase of 20% over P62 and 32% over PS-6. All lines produced fiber within the extra-long staple fiber classification limits. The fiber lengths of PS-6neLo (33.5 mm) and P62neLo (35.6 mm) were shorter than the fiber of the recurrent parents, PS-6 (35.6 mm) and P62 (36.8 mm). The fiber strengths of PS-6neLo (31.5 g tex-1) and P62neLo (33.8g tex-1) also were weaker than the fiber strengths of the recurrent parents PS-6 (34.4 g tex-1) and P62 (36.4 g tex-1). The six germplasm lines are available to breeders and other researchers in small seed quantities, and may be obtained by contacting the author.