DOI: 10.5176/2251-2489_BioTech12
Authors: Basudeba Kar, Raj Kumar Joshi and Sanghamitra Nayak
Abstract: Turmeric also known as the “golden spice” is valued world over for its medicinal and economic significance. Cultivated turmeric germplasm is highly susceptible to a range of bacterial and fungal pathogen due to non availability of a resistance source. Introgression of resistance into edible cultivars by conventional breeding has not been possible due to problems such as high genetic sterility and stigmatic incompatibility. Molecular cloning of resistance related sequences from wild genotypes and subsequent introgression can be a solution. In this study, a PCR mediated candidate gene approach made use of degenerate primers designed on conserved region of the NBS domain of nucleotide binding site-leucine rich repeat (NBS-LRR) R-genes, and provided the source for cloning analogous sequences called resistance gene candidates (RGCs) from three wild turmeric- Curcuma aromatica, Curcuma angustifolia and Curcuma zedoaria. 21 Curcuma RGCs were identified, which could be classified into four phenetic classes. A strong amino acid identity ranging from 41 to 53{6e6090cdd558c53a8bc18225ef4499fead9160abd3419ad4f137e902b483c465} together with presence of internal conserved motifs provided evidence that the isolated Curcuma RGCs belong to the non-toll interleukin receptor (non-TIR) NBS-LRR R-gene subfamily. Reverse transcription PCR with 9 Curcuma RGC specific primers showed a constitutive expression profile for 8 wild Curcuma R-gene sequences. These sequences can be used as potential guidelines to detect, isolate and subsequently transform R-genes in turmeric and other asexually reproducing plants to achieve broad spectrum disease resistance.
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