Cottonseed protein, oil, and minerals in cotton (Gossypium hirsutum L.) lines differing in curly leaf morphology

Authors: Bellaloui, Nacer; Turley, Rickie; Stetina, Salliana - Sally

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/8/2021
Publication Date: 3/11/2021
Citation: Bellaloui, N., Turley, R.B., Stetina, S.R. 2021. Cottonseed protein, oil, and minerals in cotton (Gossypium hirsutum L.) lines differing in curly leaf morphology. Plants. 10(3):525. https://doi.org/10.3390/plants10030525.
DOI: https://doi.org/10.3390/plants10030525

Interpretive Summary: Cottonseed is an important source of protein, oil, and minerals for human health and livestock feed. Therefore, it is critical to maintain high cottonseed nutritional qualities to develop new varieties of cotton with high levels of cottonseed nutrition (seed protein, oil, and minerals, including nitrogen, carbon, phosphorus, potassium, magnesium, and calcium). Leaf shape is an important trait as it is associated with photosynthesis and major nutrients absorption and metabolism, regulating processes controlling seed quality and production. Thus, the objective of this research was to compare the nutritional levels in cottonseed from two curly leaf lines (Uzbek curly leaf and DP 5690 curly leaf) and one normal leaf line (DP 5690 normal leaf). A two-year field experiment was conducted in 2014 and 2015 in Stoneville, MS, USA. The results showed that both parents (Uzbek curly leaf and DP 5690 normal leaf) had higher seed oil, and higher levels of the nutrients nitrogen, phosphorus, potassium, and magnesium than the line developed from a cross between them (DP 5690 curly leaf), indicating that curly leaf trait in the DP 5690 curly leaf suppressed some of the regulatory processes involved in oil and minerals absorption. Protein content was higher in DP 5690 curly leaf than both parents in one year but did not differ from the DP 5690 normal leaf parent in the other year. The results demonstrated that the curly leaf shape trait can affect cottonseed nutritional qualities. This research is important to breeders for cotton selection for high seed oil or protein, and to other researchers to further understand the genetic impact of leaf shapes on seed nutritional qualities. It is also important for scientists to use leaf shape as a tool for physiological, biochemical, and morphological research related to leaf development and its impact on cottonseed quality and lint production.

Technical Abstract: Cottonseed is an important source of protein, oil, and minerals for human health and livestock feed. Therefore, understanding physiological and genetic traits influencing the nutrient content is critical. To our knowledge there is no information available on the effects of leaf shape, curly leaf (CRL), on cottonseed protein, oil, and minerals. Therefore, the objective of the current research was to investigate the effect of curly leaf trait on cottonseed protein, oil, and minerals in cotton lines differing in leaf shape. Our hypothesis was that since leaf shape is known to be associated with nutrient uptake, assimilation, and photosynthesis process, leaf shape can influence seed protein, oil, and minerals. A two-year field experiment using two curly leaf lines (Uzbek CRL and DP 5690 CRL) and one normal leaf (DP 5690 wild type) line was conducted in 2014 and 2015 in Stoneville, MS, USA. The experiment was a randomized complete block design with three replicates. The results showed that both Uzbek CRL and DP 5690 wild type lines had higher seed oil, and nutrients N, P, K, and Mg than DP 5690 CRL. Calcium was higher in DP 5690 CRL for two years and protein was higher in only 2015 than the parents. Consistent significant positive and negative correlations between some nutrients were observed across the two years; other nutrients showed a positive or negative correlation with other nutrients for only one year, may be due to environmental conditions of each year, especially heat. This indicates that curly leaf trait may partially regulate the accumulation of these nutrients in seeds. The results demonstrated that leaf shape trait, curly leaf, can affect cottonseed nutritional qualities. This research is important to breeders for cotton selection for high seed oil or protein, and to other researchers to further understand the genetic impact of leaf shapes on seed nutritional quality. It is also important for scientists to use leaf shape as a tool for physiological, biochemical, and morphological research related to leaf development.