Search

Wheat (Triticum aestivum L.) production is adversely impacted by Septoria nodorum blotch (SNB), a fungal disease caused by Parastagonospora nodorum. Wheat breeders are constantly up against this biotic challenge as they try to create resistant cultivars. The genome-wide association study (GWAS) has become an efficient tool for identifying molecular markers linked with SNB resistance. This technique is used to acquire an understanding of the genetic basis of resistance and to facilitate marker-assisted selection. In the current study, a total of 174 bread wheat accessions from South Asia and CIMMYT were assessed for SNB reactions at the seedling stage in three greenhouse experiments at CIMMYT, Mexico. The results indicated that 129 genotypes were resistant to SNB, 39 were moderately resistant, and only 6 were moderately susceptible. The Genotyping Illumina Infinium 15K Bead Chip was used, and 11,184 SNP markers were utilized to identify marker–trait associations (MTAs) after filtering. Multiple tests confirmed the existence of significant MTAs on chromosomes 5B, 5A, and 3D, and the ones at Tsn1 on 5B were the most stable and conferred the highest phenotypic variation. The resistant genotypes identified in this study could be cultivated in South Asian countries as a preventative measure against the spread of SNB. This work also identified molecular markers of SNB resistance that could be used in future wheat breeding projects. [ABSTRACT FROM AUTHOR]

Proficiency and organization of the genetic variability in cultivated and wild relatives are pivotal for a particular crop improvement program. In the present scenario there has been noteworthy improvement in the development of novel genetic tools such as DNA or molecular markers and genetic maps profiling techniques. In this study, seven chickpea (Cicer arietinum L.) genotypes including some cultivars were considered (Collection Id of the seven genotypes are TZCP-1, TZCP-2, TZCP-3, TZCP-4, TZCP-5, TZCP-6 and TZCP-7). The experiment was conducted out in Random Complete Block Design (RCBD) having three replications. All the quantitative characters were collected for assessing the diversity and to find key characters in chickpea cultivars. The statistical analysis was done for all the quantitative character (viz. plant height, number of branches per plant, number of pod per plant, number of seeds per pod, test weight, seed length, seed width, days to 50% flowering, days to 50% maturity and grain yield). Analysis of variance divulged significant differences among the genotypes for all the 10 characters. An extensive range of diversity was displayed by most of the characters under study. The magnitude of phenotypic coefficient of variation (1.23% - 33.71%) in the present study was slightly wider than genotypic coefficient of variation (1.13% - 33.02%) suggesting that environmental factors have high contribution to the observed variation among chickpea accessions. The first four PC axes from the principal component analysis accounted for 91.63% of the multivariate variation among entries indicating a moderate degree of correlation among characters for these entries. The genotypic data generated through RAPD profiling of seven chickpea genotypes were used to study genetic diversity or interrelationship. The pair wise Jaccard's similarity coefficient ranged from 0.47 (TZCP-3 and TZCP-5) to 0.87 (TZCP-2 and TZCP-4). Finally, this research work helped with the analysis of genetic diversity in chickpea by using different approaches such as morphological and molecular marker system. [ABSTRACT FROM AUTHOR]

The genetic diversity assessment of agricultural crops is crucial for breeding programs aimed at enhancing crop yield, resistance to diseases, and adaptation to changing environmental conditions. In the present investigation, a comparative genetic relationship in sixteen onion genotypes was assessed utilizing dominant (RAPD) and co-dominant (SSR) marker systems. Ten RAPD and nine SSR markers showed genetic diversity remarkably and produced 503 and 107 amplicons respectively. Spearman rank correlation was used to compare the different efficiency parameters in two marker systems with respect to sixteen onion genotypes. The genetic relationship based on similarity matrix values between a pair of cultivars was higher for SSR markers than for the RAPD marker system. OPC-04 (RAPD primer) and ACM-004 (SSR primer) witnessed the highest poly-morphic bands along with other polymorphic markers that proved to be useful in grouping onion genotypes. Finally, dendrograms were constructed and compared following the mantel test to find out the genetic diversity among the germplasms. This study will be effective for a selection of efficient primers and suitable marker systems to distinguish the onion genotypes in the future. [ABSTRACT FROM AUTHOR]