Search

Cotton (Gossypium hirsutum L.) is a significant global crop and a vital raw material for industries. Studying existing cotton germplasm is crucial for discovering new genetic resources for future breeding. In this study, the effectiveness of EST-SSRs and ISSRs markers were compared for assessing genetic variation among 45 Pakistani Bt and non-Bt cotton varieties. ISSR and EST-SSR primers yielded 108 and 28 loci, respectively. The polymorphism was found 32.40% for ISSR, while 89.28% was recorded for SSR primers. Cluster analysis revealed a high level of genetic similarity for ISSR (average 0.92) and EST-SSR (average 0.85) among cotton genotypes. The mean polymorphic information content (PIC) value was 0.25 for ISSR, whereas it was recorded 0.48 for EST-SSRs. Confusion probability (Cj) exhibited a negative association with discriminating power (Dj), while Dj displayed a positive association with PIC. Marker discriminating statistics showed that EST-SSRs have a high expected heterozygosity of polymorphic loci (Hep) as compared to ISSR, along with a higher marker index value (MI). The effective multiplex ratio for ISSRs (1.40) was greater than EST-SSRs (1.12). The structural analysis revealed 6 sub-clusters for EST-SSRs and 4 sub-clusters for ISSRs. This phylogenetic study is crucial for identifying promising genotypes for breeding programs, especially given the limited genetic diversity in cotton breeding. The study showed that Bt cotton genotypes share a high genetic similarity, emphasizing the need for introducing diverse or exotic genotypes into breeding programs to enrich genetic diversity. Additionally, marker-discriminating indices can aid in selecting effective markers to assess genetic variation, facilitating the development of improved cotton varieties with desired traits. [ABSTRACT FROM AUTHOR]

Spring durum wheat occupies over 0.5 M ha in Kazakhstan and represents an important domestic and export commodity. This study aimed to characterize 151 durum wheat cultivars and advanced lines originating from eight breeding programs of the Kazakhstan–Siberia Spring Wheat Improvement Network (KASIB) between 2003 and 2018. The phenotypic characterization was performed in two contracting evaluation sites more than 1000 km apart (Almaty in the Southeast and Shortandy in the North) for two years and a total of 11 agronomic traits were recorded. Field trials at both locations followed regional agronomy practices, including sowing, harvesting, and genotype evaluation using a randomized complete block design (RCBD). The growing season was longer in Almaty, resulting in a higher number of grains per spike. Though grains are smaller in size with an overall higher yield, 243 g/m2 versus 170 g/m2, there was no correlation between germplasm performance at the two sites. Molecular characterization was performed with 10 iPBS-retrotransposons primers that resulted in a total of 345 bands and showed a mean polymorphism of 91.9%. Mean values of gene diversity (0.251), Shannon's information index (0.388), and expected heterozygosity (0.233) revealed a relatively high level of genetic diversity in the KASIB set. AMOVA revealed higher genetic variations due to differences within the populations. Marker-based cluster analysis, including STRUCTURE and neighbor-joining algorithms, divided the material into two populations with clear differences in geographic origin. Superiors and diverse germplasm identified in the study are recommended for marker assisted selection and breeding. [ABSTRACT FROM AUTHOR]

Determining optimal sowing date, optimal number of irrigation applications, and best-performing cultivars is critical to maximizing achievable sorghum yield in semiarid and arid environments. Limited research is available on interactive effects of sowing date, irrigation frequency, and genotype at multiple locations. Consequently, this study was conducted to determine impact of sowing dates, irrigation regimes, and cultivars on yield and growth traits during 2016 and 2017 at two locations in Pakistan. Experiments were laid out in a split-split design at Maize and Millets Research Institute, Yusafwala, Sahiwal, and at Bahauddin Zakariya University, Multan. Each experiment was comprised of three factors: (a) main plot irrigation regimes (I0 = Two irrigations; I1 = Four irrigations; I2 = Six irrigations; and I3 = Eight irrigations), (b) sub-plot varieties (V1 = YSS 98; V2 =Y 16; and V3 = Lasani hybrid), and (c) sub-subplot sowing dates (SD1 = 15 June; SD2 = 1 July; SD3 = 15 July, and SD4 = 30 July). Results showed that effects of sowing date, irrigation regimes, and varieties on growth and sorghum yield were significant. Planting time July was far superior for studying growth traits, phenology, and yield of sorghum varieties than early planting time (15 June), for which adverse effects on all characteristics of plant traits were observed. Various irrigations levels also affected sorghum yield, but I2 produced best results. Maximum performance index was observed in the second year of study. Decreasing productivity pattern was I2 > I3 > I1 > I0 for irrigation regimes, V3 > V2 > V1 for cultivars and SD3 > SD4 > SD2 > SD1 for sowing dates at Sahiwal and Multan. Results revealed that germplasm resource is a need of day that can be used for future plant improvements in semiarid and arid environments. [ABSTRACT FROM AUTHOR]