Fiber and Industrial Applications
NPGS Germplasm Provides Valuable Genetic Variation for Cotton Breeding
UNCOVERING GENES FROM LANDRACE ACCESSIONS FOR COTTON GENETIC IMPROVEMENT
B. Todd Cambpell
USDA-ARS, Coastal Plains Soil, Water, and Plant Research Center, 2611 West Lucas St, Florence, South Carolina 29501.
Corresponding author: todd.campbell@usda.gov
OUTLINE
1. SUMMARY
The National Plant Germplasm System (NPGS) Cotton Collection includes critical genetic diversity, including roughly 2,500 landraces (cotton lines selected by traditional farmers). Those landraces are largely underused because of limited information about their agronomic potential and photoperiod sensitivity. Nearly 20 years ago, Dr. Todd Campbell (USDA-ARS Coastal Plains Soil, Water, and Plant Research Center, Florence, SC) identified 216 day-length neutral landraces that are now undergoing genetic characterization and extensive field evaluation of agronomic traits, fiber quality, drought tolerance, and pest resistance. ARS Florence and two collaborating USDA-ARS research units developed and released nine high-quality, germplasm lines derived from those landraces that introduce valuable new diversity for cotton breeding programs.
Goals for this project include:
- Identify NPGS daylength-neutral cotton landrace accessions with agronomic potential.
- Generate comprehensive field evaluation datasets for the accessions to identify priority traits such as agronomic performance, fiber quality, drought tolerance, and pest resistance.
- Genetically characterize daylength-neutral landraces and integrate genomic and trait data to uncover causative genes for those traits.
- Develop daylength-neutral, landrace-derived cotton germplasm lines that expand the genetic diversity available to cotton breeding programs.
2. PROBLEMS ADDRESSED
The genetic base of commercial upland cotton is extremely narrow, lacking sufficient diversity for effective genetic improvement. Expanding this genetic base is essential for sustaining future gains in cotton yield and fiber quality; meeting the needs of textile manufacturers; and supporting the $35 billion cotton industry. Promising but underused resources are the landrace accessions in the NPGS Cotton Collection. These landraces, which arose during early domestication and bridge the gap between cotton wild relatives and modern cotton cultivars, remain largely unused because of limited information about their agronomic potential and widespread photoperiod sensitivity. This project was initiated to genetically characterize these accessions and to identify traits that contribute agronomic performance, fiber quality, drought tolerance, and pest resistance.
3. SOLUTIONS DEVELOPED
From the 2,500 landrace accessions in the NPGS Cotton Collection, a set of 216 day-length neutral accessions was chosen for extensively evaluation of agronomic and fiber quality performance, drought tolerance, and pest resistance. Field trials identified several day-length neutral accessions with high lint yield and fiber quality under both rainfed and irrigated conditions (Holladay et al., 2026). Collaboration with Clemson University identified eight accessions with host-plant resistance to thrips (Conzemius et al., 2023). After assessing their value as breeding parents (Campbell et al., 2019), ARS Florence—working with Dr. Lori Hinze of the USDA-ARS Crop Germplasm Research Unit (College Station, TX) and Dr. Alison Thompson of the USDA-ARS Wheat Health, Genetics, and Quality Research Unit (Pullman, WA)—developed and released nine germplasm lines containing 50% day-length neutral landrace genetic backgrounds (Campbell et al., 2021; 2025). These lines are now available to the cotton industry as valuable new parents for cotton breeding.
Collaborators involved in developing solution:
- Dr. B. Todd Campbell and Dr. Sarah Holladay Sansbury: USDA-ARS Coastal Plains Soil, Water, and Plant Research Unit, Florence, South Carolina, USA
- Dr. Lori Hinze: USDA-ARS Crop Germplasm Research Unit, College Station, Texas, USA
- Dr. Alison Thompson: USDA-ARS Wheat Health, Genetics, and Quality Research Unit, Pullman, Washington, USA
4. IMPACT
Expanding the genetic base of upland cotton is essential for increasing cotton fiber use by textile manufacturers and supporting the $35 billion cotton industry. This research targeted the landrace portion of the NPGS Cotton Collection to unlock beneficial genetic variation and broaden upland cotton’s genetic foundation. Valuable alleles associated with agronomic performance, fiber quality, drought tolerance, and pest resistance were identified, and nine high quality germplasm lines containing 50% landrace genetics were developed and released. These germplasm lines provide industry with new, genetically diverse breeding parents that will support the development of improved commercial varieties.
5. GERMPLASM
The following landrace accessions from the NPGS were used to develop nine germplasm lines of cotton:
- TX 1321 (PI 403928)
- TX 2318 (PI 607644)
- TX 1326 (PI 403933)
- TX 1327 (PI 403934)
- TX 2354 (PI 607669)
- TX 2323 (PI 607649)
- TX 1151 (PI 529967)
6. REFERENCES
Campbell BT, Hugie KL, Hinze LL, Wu J, Jones DC. 2019. Assessing the breeding potential of thirteen day-neutral landrace accessions in an upland cotton breeding program. Crop Science 59:1469–1478. https://doi.org/10.2135/cropsci2018.08.0517
Campbell BT, Hinze LL, Thompson AL, Jones M, Jones D. 2021. Registration of PD 20170048, PD 20170049, PD 20170050, PD 20170053, and PD 20170054 germplasm lines of cotton. Journal of Plant Registration 15:542–548. https://doi.org/10.1002/plr2.20128
Campbell BT, Hinze LL, Thompson AL, Jones M, Jones D. 2025. Registration of PD 20170034, PD 20170044, PD 20170057, and PD 201700560 germplasm lines of cotton. Journal of Plant Registration 19:e70006. https://doi.org/10.1002/plr2.70006
Conzemius S, Reay-Jones F, Greene J, Campbell BT, Reisig D, Wang H, Bridges W. 2023. Field screening of wild cotton, Gossypium hirsutum, landraces for resistance to thrips (Thysanoptera: Thripidae). Crop Protection 163:106113. https://doi.org/10.1016/j.cropro.2022.106113
Holladay, S, Hugie K, Subramani, J, Campbell BT. 2026. Assembly and field evaluation of a set of naturally occurring day-neutral cotton landraces under rainfed and irrigated conditions. Theoretical and Applied Genetics 139:71. https://doi.org/10.1007/s00122-026-05172-2
7. CHAPTER INFORMATION
Citation: Campbell BT. 2026. NPGS Germplasm Provides Valuable Genetic Variation for Cotton Breeding. In: Volk GM, Chen KY, Byrne PF, Bretting PK (Eds.) Plant Genetic Resources: Success Stories. Fort Collins, Colorado: Colorado State University. Date accessed. Available from https://colostate.pressbooks.pub/pgrsuccessstories/chapter/cotton-landraces-genetic-diversity/
Content originally submitted: June 15, 2026
Date of publication: July 28, 2026
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