Background: Cotton production is adversely effected by drought stress. It is exposed to drought stress at various critical growth stages grown under a water scarcity environment. Roots are the sensors of plants; they detect osmotic stress under drought stress and play an important role in plant drought tolerance mechanisms. The seedling stage is very sensitive to drought stress, and it needed to explore the methods and plant characteristics that contribute to drought tolerance in cotton. Results: Initially, seedlings of 18 genotypes from three Gossypium species: G. hirsutum, G. barbadense, and G. arboreum, were evaluated for various seedling traits under control (NS) and drought stress (DS). Afterward, six genotypes, including two of each species, one tolerant and one susceptible, were identified based on the cumulative drought sensitivity response index (CDSRI). Finally, growth rates (GR) were examined for shoot and root growth parameters under control and DS in experimental hydroponic conditions. A significant variation of drought stress responses was observed across tested genotypes and species. CDSRI allowed here to identify the drought-sensitive and drought-resistant cultivar of each investigated species. Association among root and shoots growth traits disclosed influential effects of enduring the growth under DS. The traits including root length, volume, and root number were the best indicators with significantly higher differential responses in the tolerant genotypes. These root growth traits, coupled with the accumulation of photosynthates and proline, were also the key indicators of the resistance to drought stress. Conclusion: Tolerant genotypes have advanced growth rates and the capacity to cop with drought stress by encouraging characteristics, including root differential growth traits coupled with physiological traits such as chlorophyll and proline contents. Tolerant and elite genotypes of G. hirsutum were more tolerant of drought stress than obsolete genotypes of G. barbadense and G. arboreum. Identified genotypes have a strong genetic basis of drought tolerance, which can be used in cotton breeding programs.

For about a century, plant breeding has widely exploited the heterosis phenomenon–often considered as hybrid vigor–to increase agricultural productivity. The ensuing F₁ hybrids can substantially outperform their progenitors due to heterozygous combinations that mitigate deleterious mutations occurring in each genome. However, only fragmented knowledge is available concerning the underlying genes and processes that foster heterosis. Although cotton is among the highly valued crops, its improvement programs that involve the exploitation of heterosis are still limited in terms of significant accomplishments to make it broadly applicable in different agro-ecological zones. Here, F₁ hybrids were derived from mating a diverse Upland Cotton germplasm with commercially valuable cultivars in the Line × Tester fashion and evaluated across multiple environments for 10 measurable traits. These traits were dissected into five different heterosis types and specific combining ability (SCA). Subsequent genome-wide predictions along-with association analyses uncovered a set of 298 highly significant key single nucleotide polymorphisms (SNPs)/Quantitative Trait Nucleotides (QTNs) and 271 heterotic Quantitative Trait Nucleotides (hQTNs) related to agronomic and fiber quality traits. The integration of a genome wide association study with RNA-sequence analysis yielded 275 candidate genes in the vicinity of key SNPs/QTNs. Fiber micronaire (MIC) and lint percentage (LP) had the maximum number of associated genes, i.e., each with 45 related to QTNs/hQTNs. A total of 54 putative candidate genes were identified in association with HETEROSIS of quoted traits. The novel players in the heterosis mechanism highlighted in this study may prove to be scientifically and biologically important for cotton biologists, and for those breeders engaged in cotton fiber and yield improvement programs.

Background: Cotton is an important cash crop. The fiber length has always been a hot spot, but multi-factor control of fiber quality makes it complex to understand its genetic basis. Previous reports suggested thatOsGASR9promotes germination, width, and thickness by GAs in rice, while the overexpression ofAtGASA10leads to reduced silique length, which is likely to reduce cell wall expansion. Therefore, this study aimed to explore the function ofGhGASA10in cotton fibers development.Results: To explore the molecular mechanisms underlying fiber elongation regulation concerningGhGASA10–1, we revealed an evolutionary basis, gene structure, and expression. Our results emphasized the conservative nature ofGASAfamily with its origin in lower fern plantsS. moellendorffii.GhGASA10–1was localized in the cell membrane, which may synthesize and transport secreted proteins to the cell wall. Besides,GhGASA10–1promoted seedling germination and root extension in transgenicArabidopsis, indicating thatGhGASA10–1promotes cell elongation. Interestingly,GhGASA10–1was upregulated by IAA at fiber elongation stages.Conclusion: We propose thatGhGASA10–1may promote fiber elongation by regulating the synthesis of cellulose induced by IAA, to lay the foundation for future research on the regulation networks ofGASA10–1in cotton fiber development.

The kiwifruit, Actinidia genus, has emerged as a nutritionally rich and economically significant crop with a history rooted in China. This review paper examines the global journey of the kiwifruit, its genetic diversity, and the role of advanced breeding techniques in its cultivation and improvement. The expansion of kiwifruit cultivation from China to New Zealand, Italy, Chile and beyond, driven by the development of new cultivars and improved agricultural practices, is discussed, highlighting the fruit’s high content of vitamins C, E, and K. The genetic resources within the Actinidia genus are reviewed, with emphasis on the potential of this diversity in breeding programs. The review provides extensive coverage to the application of modern omics technologies, including genomics, transcriptomics, proteomics, and metabolomics, which have revolutionized the understanding of the biology of kiwifruit and facilitated targeted breeding efforts. It examines both conventional breeding methods and modern approaches, like marker-assisted selection, genomic selection, mutation breeding, and the potential of CRISPR-Cas9 technology for precise trait enhancement. Special attention is paid to interspecific hybridization and cisgenesis as strategies for incorporating beneficial traits and developing superior kiwifruit varieties. This comprehensive synthesis not only sheds light on the current state of kiwifruit research and breeding, but also outlines the future directions and challenges in the field, underscoring the importance of integrating traditional and omics-based approaches to meet the demands of a changing global climate and market preferences.