Molecular Soil Biology 2025, Vol.16, No.3, 114-125 http://bioscipublisher.com/index.php/msb 115 summarized the effects of these practices on cotton yield, oil content, fiber quality, and economic income. This study hopes to provide some theoretical references and practical suggestions for the efficient and sustainable cultivation of oil cotton in the future, help meet the global demand for vegetable oil, and improve the overall benefits of agriculture. 2 Botanical and Agronomic Characteristics of Oil-Producing Cotton Varieties 2.1 Genetic traits linked to oil yield The fact that oil-producing cotton can produce more oil is closely related to its genetic characteristics. For example, scientists have used SSR molecular markers to identify cotton varieties that are both high-yielding and high-oil (Kusuma et al., 2018). This will help in the future selection of cotton that can produce both good fiber and more oil. In some cottons (such as Pima cotton), a gene called FAD2-1D was found to have a mutation. This mutation can increase the oleic acid content in cotton seeds. This is a good target for researchers who want to breed high-oil varieties in the future (Shockey et al., 2017). 2.2 Comparison with fiber-dominant varieties Compared with cotton that specializes in fiber production, oil-producing cotton has many differences in the amount of seed oil and the composition of the oil. Some oil-producing cotton varieties not only contain more oil, but also have better oil quality due to genetic mutations - for example, more oleic acid and less linoleic acid, which is more suitable for eating and industrial use (Shockey et al., 2017). Fiber-type cotton is mainly for producing good fiber, so less consideration is given to oil, and this part of the trait is often ignored (Kusuma et al., 2018; Shockey et al., 2017). 2.3 Growth habits, flowering/fruiting characteristics In terms of growth, flowering, and fruiting, oil-producing cotton is actually similar to ordinary cotton. However, there may be some differences when the grains mature and oil accumulates. Different cotton varieties have very different performances, whether in appearance or at the molecular level. These differences are actually advantages, because they can help us select new varieties that are both oil-rich and grow well, and provide a lot of useful genetic resources (Kusuma et al., 2018). 2.4 Optimal environmental conditions and stress tolerance The yield and oil content of oil-producing cotton are affected by the environment. Studies have found that the growth regulation mechanism of cotton is quite complex, whether in normal weather or when encountering stress such as drought and salinity. Varieties with drought and salt resistance can produce oil more stably (Gupta et al., 2023). Now, scientists have used genetic engineering and molecular breeding to improve these stress resistance capabilities, hoping to enable cotton to grow well and produce the same amount of oil even in less than ideal environments. 3 Breeding and Selection of Oil-Rich Varieties 3.1 History and evolution of breeding programs In the beginning, cotton breeding was mainly aimed at improving the quantity and quality of fiber, and few people paid attention to oil content. However, in recent years, as people's demand for edible oil and biodiesel has increased, cottonseed oil content has become a new breeding target. Studies have found that different cotton germplasm resources vary greatly in oil content. This shows that we can select varieties with more oil through breeding (De Faria et al., 2013; Sharif et al., 2019; Eldessouky et al., 2021; Wu et al., 2022). Recently, breeders have begun to systematically select varieties with high oil content, and through hybridization and generational breeding methods, the oil content of cottonseed has been significantly increased. 3.2 Key traits selected: oil content, seed size, disease resistance When breeding oil cotton, the most important goal is to increase the oil content of cottonseed. The oil content of different cotton varieties varies greatly, and many of these differences are determined by genetics. This means that through multiple generations of breeding, varieties with high oil content can be slowly selected (De Faria et al., 2013; Eldessouky et al., 2021; Malalha et al., 2023). In addition to oil content, grain size is also critical. Indicators
RkJQdWJsaXNoZXIy MjQ4ODYzNA==