Carbohydrates and genetic factors influence cell division in citrus fruits from ovule cultures. Here, we investigated the effects of various carbohydrate sources (sorbitol, maltose, galactose, and lactose) on cell proliferation, somatic embryogenesis, and plant regeneration in three Citrus unshiu cultivars (‘Miyagawa wase’ [MW], ‘Haryejosaeng’ [HW], and ‘Nankan 20 gou’ [NW]), and one C. reticulata cultivar (‘Ootaponkan’ [PM]). In PM, carbohydrate sources did not affect proliferation; MW showed a significant but marginal increase in media containing 300 mM mannitol. It also proliferated well in media supplemented with 300 mM sorbitol and a mixture of galactose and lactose. NW achieved the best rate with 100 mM mannitol and 146 mM lactose, whereas HW proliferated well with 100 mM mannitol alone. Phylogenetic analysis using 18 citrus varieties showed distinct genetic differences among the cultivars, suggesting that the differences in regeneration capacities in different carbohydrate sources could be attributed to their genetic differences. This study provides valuable insights for optimizing tissue culture protocols for mandarin varieties and may enhance the efficiency of citrus breeding and tissue culture applications.

Cotton is a globally important fiber crop, but many elite cultivars are recalcitrant to in vitro regeneration. We developed a callus-mediated plant regeneration protocol for the local G. barbadense L. cultivar Surkhan-106. Sterilized seeds were germinated in vitro, and hypocotyl and cotyledon explants were cultured on Murashige and Skoog (MS) medium with various auxin/cytokinin combinations. Robust callus induction was achieved from hypocotyl explants within 2–3 weeks. Somatic embryogenesis was induced from callus after approximately 12–14 weeks on medium supplemented with indole-3-butyric acid (IBA), 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin, and 6-benzylaminopurine (BAP). Embryogenic callus was periodically subcultured to prevent browning, and torpedo-stage somatic embryos were matured on hormone-free medium. These embryos germinated into plantlets within 10–15 days on MS medium. The entire regeneration cycle, from seed to plantlet, was completed in about 4–5 months. Hypocotyl explants showed significantly higher callus formation frequency (85%) and regeneration efficiency than cotyledon explants (60%) (ANOVA, p < 0.05). This study establishes the first efficient callus-based regeneration system for Surkhan-106, an important Uzbek cotton variety. The optimized protocol can facilitate rapid clonal propagation and genetic transformation of Surkhan-106 and other recalcitrant cotton cultivars, accelerating breeding programs for improved stress tolerance and yield.

Citations

Citations to this article as recorded by  

• Molecular and physiological indicators of heat tolerance in upland cotton ( Gossypium hirsutum L.)
  Abrorjon Y. Kurbonov, Mohigul Abdullayeva, Feruza F. Mamedova, Muxammad-Latif M. Nazirov, Naima Sh. Khojaqulova, Sanjar Sh. Djumaev, Yashin Babayev, Sayfulla Boboyev
  Journal of Plant Interactions.2026;[Epub]     CrossRef
• Molecular Characterization of Fusarium Wilt Resistance in Naturally Colored and Elite Upland Cotton Germplasm
  Abrorjon Y. Kurbonov, Feruza F. Mamedova, Sanjar Sh. Djumayev, Mukhammad Latif M. Nazirov, Naima Sh. Xojakulova, Maftuna U. Makhmudova, Ozod S. Turaev
  Journal of Natural Fibers.2026;[Epub]     CrossRef