Genotypic and environmental effects on seed and lint traits in modern commercial transgenic cotton cultivars from 2017 through 2024 in regional high-quality tests of the United States

Authors: KANDEL, SAVYATA - New Mexico State University; Zeng, Linghe; Whitelock, Derek; ZHANG, JINFA - Tennessee Technological University

Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/23/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cotton seed traits including oil content are critical to growers’ profitability. It is not known how stable the breeding for oil content in cotton seed would be across years and how lint yield would be compensated for increasing cotton seed oil content in modern cotton cultivars. In this study, we analyzed eight years (2017-2024) of Regional High Quality tests for cotton seed oil content and lint yield. Results showed that cotton seed oil content was mainly controlled by genetic factors in modern cultivars across eight years. This result indicates stability of cotton seed oil content in breeding with less influence from environmental factors. Therefore, cotton seed oil content in cultivars can be estimated under limited testing locations which can save cost in tests. Results also showed a small relationship between lint yield and cotton seed oil content. This result indicates that cotton seed oil content can be increased without dramatic yield penalty. These results provide a guideline for cotton breeders in developing cotton cultivars with improvement of cotton seed oil content.

Technical Abstract: Determination of environment, genotype and their interactions on seed and lint traits is critical for the genetic improvement of seed and fiber quality in cotton (Gossypium hirsutum L). The objectives of this study were to analyze the relative contribution of environment (E), genotype (G) and their interaction (GE) on cottonseed and lint traits; determine heritability and evaluate interrelationships among cotton traits. Eight-years (2017 through 2024) regional high-quality tests containing 11 to 22 genotypes and 3 to 9 testing locations were analyzed. Variance components of environment, genotype, and genotype X environment interaction were partitioned for cotton traits as percentages of the total variance. The genotypic variance of oil content was 41.4%, higher than E (9.7%) and GE (5.7%). Likewise, the genotypic variance of seed index was 47.0% compared to environmental (31.6%) and GE variance (4.2%). Oil and seed index have high heritability (0.95 and 0.93 respectively) compared to moderate heritability (0.78, 0.57 and 0.67) for plus, minus and free gossypol respectively. These results suggest that there is no large number of environments required for testing these traits (oil and seed index). In contrast, genotypic variance was low for seed yield, lint yield, lint percent, boll size and nitrogen where environment was a major source of variance. Therefore, those cotton traits have low heritability and may require a larger number of environments than required on oil content in tests. Besides, the non-significant correlation between lint yield and oil content (r = 0.03) implies that there would be no yield penalty on cottonseed oil content selection.