Application of WOA–SVR in Seed Vigor of High-Voltage Electric Field Treatment on Aged Cotton (Gossypium spp.) Seeds

When seeds are treated with a high-voltage electric field (HVEF) to improve seed vigor, due to the large differences in the biological electromagnetic effects on different types of seeds, the methods of variance analysis and regression analysis based on data statistics are generally used to construct the optimal electric field dose prediction model; however, the generalization performance of the prediction model tends to be poor. To solve this problem, the electric intensity, frequency and treatment time were taken as the input variables for hybrid support vector regression (SVR) analysis to establish the prediction model of the seed comprehensive germination index. The whale optimization algorithm (WOA) was used to optimize the kernel parameters of the SVR. The optimized hybrid WOA–SVR model predicted the optimal comprehensive germination index of aged cotton (Gossypium spp.) seeds to be 329, the optimal HVEF dosage was 3.64 kV/cm × 99 s, and the frequency was 1.4 Hz. The aged cotton seeds were treated with the optimal HVEF and the germination test was carried out. Compared with the check (CK), the comprehensive germination index of seeds increased by 48%. The research results provided a new method and new idea for the optimal design of parameters for seed treatment with HVEF.

Stories from the Greenhouse—A Brief on Cotton Seed Germination

Seed germination is the basis for the proliferation of sexual-reproducing plants, efficient crop production, and a successful crop improvement research program. Cotton (Gossypium spp.), the subject of this review, can be often sensitive to germination conditions. The hardness of the cotton seed coat, storage, extreme temperatures, and dormancy are some of the factors that can influence cotton seed germination. Research programs conducting studies on exotic and wild cotton species are especially affected by those hurdles. Here, we briefly review the challenges of cotton seed germination and some of the approaches our cotton breeding program explored throughout the years.

Breeding Practice Improves the Mycorrhizal Responsiveness of Cotton (Gossypium spp. L.)

Maximizing the function of indigenous arbuscular mycorrhizal (AM) fungi by choosing specific crop genotypes offers one of the few untapped opportunities to improve the sustainability of agriculture. In this study, the differences in mycorrhizal responsiveness (MR) in plant growth and shoot phosphorus (P) content among cotton (Gossypium spp. L.) genotypes from different release dates were compared and then the relationships between MR and P uptake-related traits were determined. The experimental design in a greenhouse included 24 genotypes released from 1950 to present in Xinjiang Province, inoculation with or without AM fungi, and P levels (15 and 150 mg P kg–1 added as KH2PO4). Results showed that the modern cotton genotypes exhibited a higher degree of mycorrhizal colonization, the hyphal length density (HLD), and mycorrhizae-induced changes in shoot growth than the old genotypes when inoculated with indigenous AM fungi at both the P levels. Moreover, MR was highly correlated with the HLD at low P levels and the HLD may provide useful insights for future cotton breeding aimed at delivering crop genotypes that can benefit more from AM fungi.

Effects of Gossypium spp., Balanites aegyptiaca, and Sesamum indicum seeds oils on quality of chilled and frozen-thawed ram semen

Background and Aim: Essential oils found frequently in plants are well known for their activities against bacteria, viruses, and fungi, and antioxidant properties. This study aimed to analyze egg yolk replacement by seed oils of Gossypium spp. (cotton), Balanites aegyptiaca (desert date), and Sesamum indicum (sesame) in semen extender, on ram sperm quality chilled at 4°C and frozen-thawed. Materials and Methods: Ejaculates were collected from adult rams and refrigerated at 4°C in a Tris-based extender containing 1.25%, 2.5%, 5%, and 10% of Gossypium spp., B. aegyptiaca, and S. indicum seed oils, to evaluate which were the two best extenders for comparison with BIOXcell, a commercial extender for deep freezing ram semen. Results: The data showed that sperm movements analyzed by the CASA system were faster in extenders supplemented with 2.5-5% of cottonseed oil and 1.25-10% of sesame oil, whereas in the extender containing B. aegyptiaca oil, all seminal parameters studied had the worst values. During the sperm-freezing process, 5% of cottonseed oil and 5% sesame seed oil were selected from the first study, with sesame oil reaching the best sperm quality. Thus, sperm motility and velocity were 44.14±13.99%, 24.44±12.6%, and 25.92±11.50%; and 20.26±9.56%, 8.76±6.38%, and 9.42±5.40%, respectively, for sesame oil, cottonseed oil, and BIOXcell. Conclusion: In summary, 2.5-10% of cottonseed oil and 1.25-10% of sesame seed oil can replace egg yolk in a Tris–egg yolk–based extender. Moreover, a Tris-based extender supplemented with 5% sesame seed oil could be an alternative for deep freezing ram semen, even though these results need to be confirmed with semen collected from rams with appropriate sexual rest.

Ratooning Annual Cotton (Gossypium spp.) for Perennial Utilization of Heterosis

This paper reviews an important topic within the broader framework of the use of ratoon cotton for the development of a cost-saving and efficient method for the perennial production of hybrid cotton seeds. Cotton has a botanically indeterminate perennial growth habit and originated in the tropics. However, cotton has been domesticated as an annual crop in temperate areas worldwide. Ratoon cultivation has an important application value and is important for cotton production, breeding, and basic research. In particular, ratooned male-sterile lines have four advantages: an established root system, an indeterminate flowering habit, ratooning ability, and perennial maintenance of sterility in the absence of a matched maintainer. These advantages can help reduce the costs of producing F1 hybrid cotton seeds and can help breed high-yielding hybrid combinations because ratooning is a type of asexual reproduction that allows genotypes to remain unchanged. However, ratooning of cotton is highly complex and leads to problems, such as the accumulation of pests and diseases, decreased boll size, stand loss during severe winters, and harmful regrowth during mild winters, which need to be resolved. In summary, ratoon cotton has advantages and disadvantages for the production of hybrid cotton seeds, and future prospects of ratooning annual cotton for the perennial utilization of heterosis are promising if the mechanization of seed production can be widely applied in practice.