Expanding genetic variability of cultivated cotton (Gossypium hirsutum) is essential for improving fiber quality and pest resistance. This study synthesized allotetraploids through interspecific hybridization between G. herbaceum (A₁) and G. nelsonii (G₃). Upon chromosome doubling using 0.2% colchicine, fertile F₁C allotetraploids (A₁A₁G₃G₃) were developed. Cytogenetic analysis confirmed chromosome stability of synthetic allotetraploids, and 74 polymorphic SSR markers verified hybridity and parental contributions. The F₁C hybrids exhibited enhanced resistance to cotton aphids (Aphis gossypii) and whiteflies (Aleyrodidae), with respective infestation rates of 5.2–5.6% and 5.4–5.8%, lower than those of G. hirsutum cv. Ravnak-1 (22.1% and 23.9%). Superior fiber length (25.0–26.0 mm) was observed in complex hybrids and backcross progeny, confirming the potential for trait introgression into elite cultivars. Phylogenetic analysis based on SSR data clearly differentiated G. herbaceum from Australian wild species, demonstrating successful bridging of divergent genomes. The F₁C hybrids consistently expressed dominant G. nelsonii-derived traits regardless of the hybridization direction and clustered phylogenetically closer to the wild parent. These synthetic allotetraploids could broaden the genetic base of G. hirsutum, addressing cultivation constraints through improved biotic stress resilience and fiber quality traits. The study establishes a robust framework for utilizing wild Gossypium species to overcome genetic bottlenecks in conventional cotton breeding programs.

Background/Objectives: The classification and phylogenetic relationships of Gossypium hirsutum L. landraces, despite their proximity to southern Mexico, remain unresolved. This study aimed to clarify these relationships using SSR markers and hybridization methods, focusing on subspecies and race differentiation within G. hirsutum L. Methods: Seventy polymorphic SSR markers (out of 177 tested) were used to analyze 141 alleles and calculate genetic distances among accessions. Phylogenetic relationships were determined using MEGA software (version 11.0.13) and visualized in a phylogenetic tree. ANOVA in NCSS 12 was used for statistical analysis. Over 1000 inter-race crosses were conducted to assess boll-setting rates. Results: Distinct phylogenetic patterns were identified between G. hirsutum subspecies and races, correlating with boll-setting rates. Latifolium, richmondii, and morilli showed no significant increase in boll-setting rates in reciprocal crosses. Cultivars Omad and Bakht, as paternal parents, yielded higher boll-setting rates. Religiosum and yucatanense displayed high boll- and seed-setting rates as maternal parents but low rates as paternal parents. Additionally, phylogenetic analysis revealed a close relationship between cultivars ‘Omad’ and ‘Bakht’ with G. hirsutum race richmondii, indicating their close evolutionary relationship. Conclusions: Reciprocal differentiation characteristics of G. hirsutum subspecies and races, particularly religiosum and yucatanense, should be considered during hybridization for genetic and breeding studies. Understanding the phylogenetic relationships among G. hirsutum taxa is crucial for exploring the genetic diversity of this economically important species.

Naturally colored cotton offers ecological advantages by eliminating the need for chemical dyeing; however, its limited fiber quality restricts its commercial utilization. The main goal of this study was to evaluate the potential of the SSR marker BNL1604 for marker-assisted selection in naturally colored cotton (G. hirsutum L.) and to assess fiber quality variation among hybrid progenies derived from crosses between colored and elite white-fiber cultivars. As an expected outcome of this approach, we also assessed whether hybridization of naturally colored lines with elite white-fiber cultivars could contribute to the improvement of fiber quality traits in segregating progenies. Five colored lines (brown and green), three elite cultivars, and fifteen derived F₃ progenies were analyzed. Fiber traits, including upper half mean length (UHML), strength, elongation, and micronaire, were measured using HVI. Genotyping was conducted with BNL1604, and in silico mapping localized this marker to chromosome A07, with a homoeologous region on D07. White-fiber cultivars exhibited superior fiber length (33.4–35.4 mm) and strength (>31 g·tex⁻¹) compared with colored lines. Several F₃ hybrids exhibited transgressive segregation (progeny with trait values significantly exceeding those of both parents, as confirmed by frequency distribution and ANOVA analyses). For instance, the F₃ (C-6577 × L-4099) hybrid achieved UHML values of 30.51 mm and strength > 31.93 g·tex⁻¹. Most progenies maintained optimal micronaire (4.0–4.9). It was concluded that the presence of the 107 bp allele of BNL1604 marker was strongly associated with high-quality fiber, specifically improved fiber strength and length. In silico annotation revealed candidate genes near the BNL1604 locus linked to fiber development. These findings highlight the potential of combining hybridization with selection based on the presence of this 107 bp allele to develop high-quality, naturally colored cotton cultivars.

Strawberry (Fragaria × ananassa Duch.) is a widely cultivated and economically important fruit crop with increasing consumer demand worldwide. Nowadays, in Uzbekistan, strawberry cultivation surpasses that of many other fruits and vegetables in terms of production volume. However, most genetic studies have focused on a limited set of cultivars, leaving a substantial portion of varietal diversity unexplored. This study aimed to evaluate the genetic variability and heritability among selected strawberry cultivars, as well as correlations between certain valuable agronomic traits, using molecular and statistical approaches. Polymorphism analysis was performed, using 67 gene-specific SSR markers, through PCR, and allele variations were observed in 46.3% of the markers analyzed. Among them, 31 markers displayed polymorphic bands, identifying fifty alleles, with one to four alleles per marker. Phylogenetic analysis was performed using MEGA 11 software, while statistical evaluations included AMOVA (GenAIEx), correlation (OriginPro), and descriptive statistics based on standard agronomic methods. Additionally, the degree of cross-compatibility and pollen viability among the cultivars were studied, and their significance for cultivar hybridization was analyzed. The highest fruit weight was observed in the Cinderella cultivar (26.2 g), and a moderate negative correlation (r = −0.688) was found between fruit number and fruit weight. These findings demonstrate the potential of molecular tools for assessing genetic diversity and provide valuable insights for breeding programs aimed at developing improved strawberry cultivars with desirable agronomic traits.

Cotton is a globally important crop, with fiber quality traits governed by complex quantitative trait loci (QTL). However, the utility of QTL data is often limited due to inconsistencies across studies. This study conducted a comprehensive Meta-QTL (MQTL) analysis by integrating 2864 QTLs from 50 independent studies published between 2000 and 2024. Of these, 2162 high-confidence QTLs were projected onto a consensus genetic map using BioMercator V4.2.3, resulting in the identification of 75 MQTLs across the cotton genome. These MQTLs exhibited significantly reduced confidence intervals and enhanced statistical support, with 14 MQTLs reported for the first time. Several MQTLs, including MQTLchr7-1, MQTLchr14-1, and MQTLchr24-1, were identified as stable clusters harboring key fiber quality and stress tolerance traits. Candidate gene analysis within select MQTL regions revealed 75 genes, 38 of which were annotated with significant gene ontology terms related to lignin catabolism, flavin binding, and stress responses. Notably, GhLAC-4, GhCTL2, and UDP-glycosyltransferase 92A1 were highlighted for their potential roles in fiber development and abiotic stress tolerance. These findings provide a refined genomic framework for cotton improvement and offer valuable resources for marker-assisted selection (MAS) and functional genomics aimed at enhancing fiber quality, yield, and stress resilience in cotton breeding programs.

The restricted genetic diversity of current cotton varieties (Gossypium hirsutum L.) considerably limits breeding opportunities aimed at enhancing fiber quality and resistance to environmental factors. Wild types of allotetraploid cottons are valuable sources of genetic variation, and their breeding potential has not yet been fully utilized. In this study, the inheritance and variability of important agronomic traits were analyzed in F₁ and F₂ hybrid generations obtained from intra- and interspecific crosses involving G. hirsutum, G. barbadense, and G. darwinii. The phylogenetic relationships of allotetraploid species were analyzed using molecular-genetic and cytogenetic methods, and their breeding potential was evaluated. Cytogenetic analysis of the F₁ hybrids revealed the occurrence of univalents at metaphase I of meiosis, while bivalent numbers reached 25.9 in some hybrid combinations. Based on molecular marker analysis, significant genetic differences and polymorphism were identified between var. gambia and var. m. palmerii. There were reciprocal translocations, shown as multivalents, during ecotypic differentiation in other cross combinations. Positive transgressive segregation for the enhancement of fiber length was identified in F₂ populations. Notably, in certain hybrid combinations, fiber length extended to 40.9 mm. Furthermore, molecular analysis identified 113 unique alleles across the genotypes examined. These findings affirm that wild and exotic allotetraploid cotton forms constitute a significant source of genetic diversity for breeding programs.