Importance of cottonseed oil and improvement of its quality and quantity through different breeding strategies

Upland cotton (Gossypium hirsutum) is the world’s leading fiber crop and one of the most important oilseed crops. Genetic improvement of cotton has primarily focused on fiber yield and quality. However, there is an increased interest and demand for enhanced cottonseed traits, including protein, oil, fatty acids, and amino acids for broad food, feed and biofuel applications. As a byproduct of cotton production, cottonseed is an important source of edible oil in many countries and could also be a vital source of protein for human consumption. The focus of cotton breeding on high yield and better fiber quality has substantially reduced the natural genetic variation available for effective cottonseed quality improvement within Upland cotton. However, genetic variation in cottonseed oil and protein content exists within the genus of Gossypium and cultivated cotton. A plethora of genes and quantitative trait loci (QTLs) (associated with cottonseed oil, fatty acids, protein and amino acids) have been identified, providing important information for genetic improvement of cottonseed quality. Genetic engineering in cotton through RNA interference and insertions of additional genes of other genetic sources, in addition to the more recent development of genome editing technology has achieved considerable progress in altering the relative levels of protein, oil, fatty acid profile, and amino acids composition in cottonseed for enhanced nutritional value and expanded industrial applications. The objective of this review is to summarize and discuss the cottonseed oil biosynthetic pathway and major genes involved, genetic basis of cottonseed oil and protein content, genetic engineering, genome editing through CRISPR/Cas9, and QTLs associated with quantity and quality enhancement of cottonseed oil and protein.

Upland cotton is an important fiber and oilseed crop. Cottonseed produces approximately 15% of farm gate value in cotton production. Therefore, improvement of cottonseed oil can significantly increase the economic return of cotton production with the same land use and investment. However, genetic variation in cottonseed oil is highly limited within upland cotton, limiting the genetic gain in cottonseed oil. Introgression breeding can alleviate this bottleneck effect by introducing desirable genes from Pima to Upland cotton. The objective of this study was to evaluate introgression lines (ILs) for better cottonseed oil. A population of 590 ILs, developed from a cross between Acala 1517-99 and Pima, was grown in Las Cruces, NM in 2022 which was used for the fatty acid methyl ester analysis through gas chromatography. There was a high level of variation in cottonseed oil and fatty acids. In the biplot, cottonseed oil was positively correlated with oleic acid and negatively related with palmitic acid. The cluster analysis identified a group of ILs with the highest average oil and oleic acid. As a result, ILs with better oil profiles were identified for further testing and analysis toward the development of high-quality cotton varieties with higher and better oil.

Improvement of qualitative and quantitative traits in cotton under normal and stressed environments using genomics and biotechnological tools: A review

Cottonseed oil is recognized as an important oil in food industry for its unique characters: low flavor reversion and the high level of antioxidants (VitaminE) as well as unsaturated fatty acid. However, the cottonseed oil content of cultivated cotton (Gossypium hirsutum) is only around 20%. In this study, we modified the accumulation of oils by the down-regulation of phosphoenolpyruvate carboxylase 1 (GhPEPC1) via RNA interference in transgenic cotton plants. The qRT-PCR and enzyme activity assay revealed that the transcription and expression of GhPEPC1 was dramatically down-regulated in transgenic lines. Consequently, the cottonseed oil content in several transgenic lines showed a significant (P < 0.01) increase (up to 16.7%) without obvious phenotypic changes under filed condition when compared to the control plants. In order to elucidate the molecular mechanism of GhPEPC1 in the regulation of seed oil content, we quantified the expression of the carbon metabolism related genes of transgenic GhPEPC1 RNAi lines by transcriptome analysis. This analysis revealed the decrease of GhPEPC1 expression led to the increase expression of triacylglycerol biosynthesis-related genes, which eventually contributed to the lipid biosynthesis in cotton. This result provides a valuable information for cottonseed oil biosynthesis pathway and shows the potential of creating high cottonseed oil germplasm by RNAi strategy for cotton breeding.

ABSTRACTBlending polyunsaturated oils with highly saturated or monounsaturated oils has been studied extensively; however, in literature there is negligible information available on the blending of refined cottonseed oil with palm olein oil. Blending could enhance the stability and quality of cottonseed oil during the frying process. In the present study, the effects of frying conditions on physicochemical properties of the palm olein-cottonseed oil blends (1:0, 3:2, 1:1, 2:3, and 0:1, w/w) were determined and compared to the pure oils. The frying process of frozen French fries was performed in duplicate at 170 ± 5°C for 10 h without interruption. The oil degradations were characterized during deep-frying applications; peroxide, free fatty acid, and iodine value by standardized methods, fatty acid profile by using a gas chromatography-flame ionization detector, polar and polymeric compounds by using the high-performance size exclusion chromatography/evaporative light scattering detector technique. The present study clearly indicated that the oxidative and frying performances of pure palm olein oil and cottonseed oil significantly improved by blending application. Results clearly indicated that the frying performance of cottonseed oil significantly improved by the blending with palm olein oil. Except that free fatty acid content, all the physicochemical variables were significantly influenced by type of pure and blend oils. By increasing the proportion of palm olein oil in cottonseed oil, the levels of polyunsaturated fatty acids decreased, while saturated fatty acid content increased. The progression of oxidation was basically followed by detecting polar and polymeric compounds. The fastest increments for polar and polymeric compounds were found as 6.30% level in pure cottonseed oil and as 7.07% level in 40% cottonseed oil:60% palm olein oil blend. The least increments were detected as 5.40% level in 40% cottonseed oil:60% palm olein oil blend and 2.27% level in 50% cottonseed oil:50% palm olein oil blend. These levels were considerably below the acceptable levels recommended by the official codex. Therefore, the present study suggested that blending of cottonseed oil with palm olein oil provided the oil blends (50% cottonseed oil:50% palm olein oil and 40% cottonseed oil:60% palm olein oil, w/w) with more desirable properties for human nutrition.

The variation in oil content, oil yield and fatty acid compositions of 103 sesame landraces was investigated. The landraces varied widely in their oil quantity and quality. The oil content varied between 41.3 and 62.7%, the average being 53.3%. The percentage content of linoleic, oleic, palmitic and stearic acids in the seed oil ranged between 40.7–49.3, 29.3–41.4, 8.0–10.3 and 2.1–4.8%, respectively. Linolenic and arachidic acids were the minor constituents of the sesame oil. Linoleic and oleic acids were the major fatty acids of sesame with average values of 45.7 and 37.2%, respectively. The total means of oleic and linoleic acids as unsaturated fatty acids of sesame were about 83% which increases the suitability of the sesame oil for human consumption. The superiority of the collection was observed in oil content. The oil content of a few accessions was above 60%, proving claims that some varieties of sesame can reach up to 63% in oil content. The accessions with the highest oil content were relatively richer in the linoleic acid content while there were some landraces in which linoleic and oleic acid contents were in a proportion of almost 1:1. The results obtained in this study provide useful background information for developing new cultivars with a high oil content and different fatty acid compositions. Several accessions could be used as parental lines in breeding programmes aiming to increase sesame oil quantity and quality.

Currently, genetic improvement in oil and lignan content is a major objective in sesame breeding. As a prerequisite to meet the objective, the diversity of these traits of sesame germplasm was examined. Solvent extraction of the harvested seeds demonstrated variation in oil content ranging from 39% to 49% across the sesame accessions tested. High performance liquid chromatography of oil samples showed sesamin and sesamolin as the only lignans present in the oil, with their amount in the range of 2.74–10.55 g L−1 and 2.49–13.78 g L−1, respectively. Coefficient of variation for oil content remained the highest in brown and black seeded accessions, whereas it remained at maximum for sesamin and sesamolin in white seeded ones. Pearson analysis showed a positive correlation between oil and lignan content. It was concluded that Indian sesame accessions exhibit considerable variation in oil and lignans content. The S. indicum varieties with a desirable composition of oil and/or lignans have been identified and recommended for incorporation in breeding programs, as well as for specific human use.

This investigation was carried out to determine the variability in oil content with the aim to identify genotypes of argan tree expressing high oil yield. The 150 argan trees were collected from five provenances in south west of Morocco over 3 years (2008–2010) and were screened from their oil content using Soxhlet method based on the 840 samples. Univariate and multivariate analysis were used to study the genetic variation between and within provenances. According to the results on the mean of the 3 years, the oil content was ranged from 38.45 to 62.54 %. The genotypes from Aoulouz and Had Dra expressing high oil yield. Variance components for fruit, seed, kernel traits and oil content showed significant differences (P < 0.01) among years, provenances, genotypes and their interaction. Principal component analysis proved that fruit, seed, kernel, weight traits are correlated with oil content and are discriminate characters between the genotypes. The results of the cluster analysis support the results of the principal component analysis, showing no correlation between oil content with geographical localization parameters. For all the promising genotypes, at least 25 % were found to be better and exceed the oil mean of the provenance for 3 years. So, 31 promising elite genotypes were preselected, and open new ways for future comparative test of them in diverse environments.

Periodic variation in kernel oil content and fatty acid profiles of Calophyllum inophyllum L.: A medicinal plant in northern Australia

Periodic variation in kernel oil content and fatty acid profiles of Calophyllum innophyllm L.: A potential biodiesel feedstock in Australia

Genome-wide association study of the oil content in upland cotton (Gossypium hirsutum L.) and identification of GhPRXR1, a candidate gene for a stable QTLqOC-Dt5-1

Eight parental cultivars and 56 hybrids of cotton (Gossypium hirsutum) were grown in normal and nitrogen-deficient conditions in the field to investigate the effect of nitrogen regime on the oil and protein contents and their combining ability. The mean oil and protein contents of the parental cultivars greatly varied with the nitrogen regime, which indicated their nitrogen sensitivity. The genetic variability of oil and protein contents was low in the same nitrogen regime, but was high in the comparison between the normal and nitrogen-deficient conditions. The nitrogen regime affected not only the oil and protein contents and ranking of parental cultivars, but also the combining ability. A normal nitrogen level was found to be more useful for selecting the additive type of gene action in breeding of cotton.

Introduction and Objectives: The fatty acid profile of cotton seed oil, can be used to assess its nutritional value as ell the industrial applications of the oil as well. The significant amino acids such as Lipase, phytase, and lecithin were confirmed to found in cotton seed oil .Additionally, cotton seed oil is made to contained substantial natural antioxidants and α-tocopherols which give it shelf life longer than other related edible oils. The aim of this study is evaluate the physicochemical properties and characterized the Gossypium hirsutum oil using GC-MS analysis.&#x0D; Materials and Methods: The cotton seed oil was extracted using soxhlet extraction procedure. The physicochemical parameters such as Acid value, Free Fatty acids content, Iodine value, Saponification value, Peroxide value, Viscosity(40°C), Refractive Index, Moisture content, Specific gravity (30°C), and colour index were determined by standard procedures described by AOAC , while the ester value was determined by baltes method. The oil was characterized using gas chromatography mass spectrophotometry (GC-MS) analysis.&#x0D; Results: The physicochemical parameters showed that the acid value, free fatty acids content, iodine value, Saponification value, ester value, Peroxide value, viscosity, refractive index, moisture content, Specific gravity of the oil were 0.94±0.020 (mgKOH/gOil), 0.34±0.016%, 75.70±0.150gI/100g, 210.9±0.023millieqv/g, 209.4±0.027mgKOH/gOil, 8.82±0.010meq/kg, 4.41±0.113cSt, 1.383±0.003, 0.22±0.010%, 0.915±0.001 respectively. While the the oil was found to be Dark red in color. The GC-MS analysis of cotton seed oil shows the presence of twenty five (25) chemical compound ,in which six (6) where found to have biological activity related to Antibacterial activity, Anticancer Drug, Antiseborrhoeic , Anti-inflammatory, Hypocholesterolemic, Cancer Preventive, Insectifuge, Antiarthritic, Antieczemic Hepatoprotective, Antiandrogenic, Nematicide, Antihistaminic, Cytoprotective activity and Anti-inflammatory this includes 4,8-Diaza-2,9-dibenzoyl-5, 6-diphenyl-2,8-decadienedioic acid tridecan-7-ol, Undecanoic acid, octadecanoic acid, 9,12-Octadecadienoic acid(Z,Z)-, (E)-hexadec-7-enal and (Z)-7-Hexadecenoic acid respectively.&#x0D; Conclusion: Cotton seed oil's physicochemical parameters were found to be within the NAFDAC and Cordex standards, liquids in nature, unsaturated, and slow to oxidation and rancidity and it is suitable for consumption . The GC-MS analysis of cotton seed oil reveals the presence of twenty-five (25) chemical compounds, six (6) of which exhibit biological activity and can be used in industrial, food, additive, and pharmacological formulations.

Cotton (Gossypium hirsutum) is globally cultivated for its high-quality fiber; yet, its seed, rich in oil and protein, offers untapped potential for various applications, including food, feed, and industry. With cottonseed oil gaining renewed attention as a valuable co-product, efforts to enhance oil content must contend with long-standing breeding priorities focused on lint yield and fiber quality. A central challenge lies in the complex and often antagonistic genetic relationships between oil accumulation and key agronomic traits. Notably, negative correlations between seed oil content and fiber yield, as well as the pleiotropic nature of several regulatory genes and Quantitative Trait Loci (QTLs), present significant barriers to dual-trait improvement. This review synthesizes current knowledge on the genetic and molecular interplay between cottonseed oil content and other agronomic traits. We examine the architecture of oil-related QTLs and pleiotropic loci, co-expression patterns of shared transcriptional regulators, and metabolic trade-offs influencing carbon allocation between seed and fiber. Recent advances in genomics, transcriptomics, and systems biology are explored as tools to disentangle these trait interactions. We highlight strategies such as multi-trait genomic selection, CRISPR-based uncoupling of antagonistic loci, and the use of wild and exotic germplasm to overcome linkage drag. By providing an integrative overview of the constraints and opportunities at the intersection of oil and agronomic trait improvement, this review lays the groundwork for the development of dual-purpose cotton ideotypes. We propose a conceptual framework for breeding programs to simultaneously enhance fiber yield and oil productivity in a sustainable and climate-resilient manner.

The aim of this study is to examine the variability of yield and fatty acid composition of argan seed oil (Argania spinosa L.) in four provenances, and to find the relationship between fatty acid composition and environmental conditions. Twenty genotypes were preselected and evaluated for fatty acids composition during 3 years (2008–2010). The oil was extracted by a Soxhlet and the fatty acids composition was determined using gas chromatography. The results revealed a variation in seed oil content (51.83–57.50 %). Total saturated fatty acids content (C14:0; C16:0; C18:0; C20:0) ranged from 19.53 to 20.29 %, with lower content in Had Dra and Biougra than other provenances. However, the concentration of total unsaturated fatty acids ranged from 79.56 to 80.29 %, with a higher percentage of monounsaturated fatty acid (C16:1; C18:1; C20:1) (47.60 %) in Aoulouz and a higher percentage of polyunsaturated fatty acid (C18:2; C18:3) (35.53 %) in Biougra provenance. No correlation between oil content and fatty acid compositions with the morphological data (mother tree, fruit and seed forms) was found. The geographical localization and fatty acid content were not correlated with oil content. The study proved a significant contribution of environmental conditions to the variation in fatty acid composition. We conclude that there is a highly significant variation both in oil content and fatty acid composition in the argan provenances that can be used for its improvement.