To unravel the molecular mechanism of defense against blister blight (BB) disease caused by an obligate biotrophic fungus, Exobasidium vexans, transcriptome of BB interaction with resistance and susceptible tea genotypes was analysed through RNA-seq using Illumina GAIIx at four different stages during ~20-day disease cycle. Approximately 69 million high quality reads were assembled de novo, yielding 37,790 unique transcripts with more than 55% being functionally annotated. Differentially expressed, 149 defense related transcripts/genes, namely defense related enzymes, resistance genes, multidrug resistant transporters, transcription factors, retrotransposons, metacaspases and chaperons were observed in RG, suggesting their role in defending against BB. Being present in the major hub, putative master regulators among these candidates were identified from predetermined protein-protein interaction network of Arabidopsis thaliana. Further, confirmation of abundant expression of well-known RPM1, RPS2 and RPP13 in quantitative Real Time PCR indicates salicylic acid and jasmonic acid, possibly induce synthesis of antimicrobial compounds, required to overcome the virulence of E. vexans. Compendiously, the current study provides a comprehensive gene expression and insights into the molecular mechanism of tea defense against BB to serve as a resource for unravelling the possible regulatory mechanism of immunity against various biotic stresses in tea and other crops.

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The gaining attention of underutilized oat crops for both food and feed, mining of quality and yield related genes/QTLs from available germplasms of oat is need of the hour. The large family of grasses has a vast number of germplasms that could be harnessed for bio-prospecting. The selection of cross-compatible oat germplasms by molecular markers could be used for the introgression of the novel traits into the elite background of oats. The process needs a thorough study of genetic diversity to see the evolutionary relatedness among germplasms. Considering this, in the present study, the genetic diversity of 38 oat germplasms with 12 agro-morphological traits was carried out using 22 Inter Simple Sequence Repeat (ISSR) markers. We found a high level of polymorphism and 158 distinctive alleles; on average 7.18 alleles per primer, further, high-yielding genotypes were identified with the help of phenotypic data and genetic diversity was analyzed by using DNA fingerprint-based principal component analysis, UPGMA dendrogram. Among these 38 germplasms; eight were identified as superior under high grain yield (OS-424, OS-403, NDO-1101, OL-10, UPO-212, OS-405, OS-6, and OS-346) and another eight germplasms were identified as superior for the high fresh weight (for fodder purpose, NDO-711, RO-19, OL-14, OL-1760/OL-11, NDO-10, UPO-212, UPO-06-1, and RO-11-1). These results suggest that germplasms that are closely related (Cross-compatible) and have good potential for desirable traits could be used for varietal development by using marker-assisted selection.

Alliums are the most popular for their culinary usage and nutraceutical benefits. Their productions are greatly affected by the multiple biotic and abiotic stresses. Poor characterizations of genetic resources are the major bottleneck in genetic improvement of alliums. Chloroplast derived simple sequence repeat (cpSSR) have recently gained much popularity due to their maternal inheritance and low recombination along with their hypervariable nature. In this study, 22 chloroplast-derived SSR markers were produced from chloroplast genomes of A. cepa and A. sativum. Repeat comparison revealed tri nucleotide repeats were in higher proportion (50%) compared to other repeat motifs. The number of alleles ranged from 2 to 4, heterozygosity from 0.009 to 0.540, and PIC from 0.007 to 0.427. The polymorphism survey and clustering of twenty-two cpSSR markers of twenty-five alliums, lead to three groups (groups I, II, and III), indicated the usefulness of these cpSSR markers. This demonstrated that cultivated A. cepa and A. sativum belong to different groups II than most wild alliums, confirming the usefulness of the AccpSSR and AscpSSR markers that will allow introduction of desirable biotic and abiotic tolerance traits from various wild alliums to selected cultivated alliums. In addition, these cpSSRs were validated in 79 alliums, divided them into three groups using Jaccard dissimilarity and Bayesian model-based structure analysis. Subsequent clustering allowed us to identify diverse alliums, for constructing core collection of germplasm resource. The study will be useful for molecular breeding and genomic selection based crop improvement.