Improving disease resistance in mungbean - A combined genetic and biotechnological approach

Pulses are edible grains (seeds) of leguminous crops and are a main source of non-meat protein in the diet for approximately 1/3 of the Indian population. Pulses are also rich in dietary fibre, vitamins, and minerals. Mungbean is one the most important pulse crops grown and consumed in India with demand for this pulse significantly exceeding production forcing India to import mungbean from other countries. Although high yielding mungbean varieties are available, at the farm gate often only low yields are achieved largely due to the fungal diseases such as Cercospora leaf spot caused by Cercospora canescens and powdery mildew caused by Erysiphe polygoni. In collaboration with partners in India, we are pursuing an integrated approach to gain a better understanding of these economically damaging diseases and to aid development of disease resistant varieties through conventional marker assisted breeding and also by utilising emerging biotechnology tools such as RNAi and genome editing. This involves extensive phenotyping and genotyping by sequencing followed by Genome-wide association studies (GWAS) of fungal isolates sampled from all main mungbean growing states in India as well as diverse mungbean germplasm accessions and targeted mapping populations. This will allow us to pinpoint the regions of the DNA that contribute for pathogenicity and for disease resistance of the pathogens and the plant, respectively. In parallel, we will assess potential of CRISPR/Cas9 and host-induced gene silencing (HIGS) as more rapid biotechnology solutions for introducing broad spectrum disease resistance into elite mungbean varieties. Growing disease resistant varieties will allow Indian farmers to produce a more stable and improved mungbean yield, thus contributing to India’s agricultural environmental and economic sustainability and directly improving welfare for the poorest in India by improving food security.