Research Projects

Dwarfism is crucial for modern tree cultivation, particularly in fruit crops like cashew. However, the development of dwarf varieties has been slow due to the complexities of tree breeding and the poorly understood genetic mechanism of tree size. The advent of next-generation sequencing technologies has enabled gene mapping and identification of genomic loci regulating traits faster, easier, and economical in reference genomes. Cashew, the second most important nut tree crop in the world and a major foreign exchange earner for India, offers potential means for increasing productivity. This investigation aims to understand the molecular basis of brachytic dwarfism in cashew and generate genomic resources for its genetic characterization using an F1 developed between the first dwarf cashew variety in India, Nihara, and the tall commercial variety, Anakayam. The segregating F2 population of the above cross revealed that dwarfism in Nihara is under monogenic recessive inheritance, and the phenotype could be differentiated from the tall as early as 1 week after germination. The study aims to reveal the dwarfing mechanism in Nihara, which can be used as a donor parent for breeding dwarf varieties and as a dwarfing root stock. It also aims to identify differentially expressed genes/pathways leading to the regulation of dwarfism in Nihara, genetic diversity in germplasms conserved at the station using newly developed SSR markers, and the identification of dwarfism-linked genetic markers. Future research could extend to identify the genetic mechanism and utilize candidate genes for developing dwarf varieties of cashew. The brachytic dwarfism with a monogenic inheritance, easily phenotyped in segregating F2, serves as an excellent resource for elucidating dwarfism in cashew.