An integrated genomics/genetics approach for development of mungbean varieties with improved disease resistance

Pulses, are edible grains (seeds) of leguminous crops i.e. peas, beans and lentils, and are a staple food source for the majority of India's 1.3 billion people. Pulses are a main source of non-meat protein in the diet for approximately 1/3 of the Indian population, with demand growing due to the expanding Indian population. Pulses have a high protein content (23%), are also rich in dietary fibre, B vitamins, and minerals, particularly iron, potassium, magnesium and zinc, and are low in fat. Despite being high in iron, iron-induced anaemia has remained a top cause of disability in India for the past decade. Therefore, pulses offer significant nutritional and health benefits that supplement wheat and rice based diets of the poor, including the vegetarian populations of India and other countries across Asia. Like other legumes, pulse crops are able to fix atmospheric nitrogen through their symbiotic association of specialized root bacteria that can improving soil fertility (green manure) for subsequent crops that contribute to the higher yields of succeeding cereal crops such as wheat or rice, thus reducing fertilizer requirements and thus impact on the environment by reducing greenhouse gas emission and water pollution. Mungbean, is one the most important pulse crops grown and consumed in India. Locally it is known as green gram, and is an ancient crop that was domesticated in India some 3,5 million years ago, and currently ranks third among all pulses grown within India after chickpeas and pigeonpeas. It is a versatile crop that only takes 60-65 days to harvest; in addition, mungbeans are not only grown for their seeds but also as forage (fodder for cattle). However, demand for mungbean, in India significantly exceeds current Indian production levels, where India now directly imports mungbean to meet its demand. And although high yielding mungbean varieties are available, lack of productivity has contributed to Indian food insecurity (the state of being without reliable access to a sufficient quantity of affordable, nutritious food) and malnutrition of the poorest populations. Indian farmers generally see less than half of the mungbean yield potential of these higher yielding varieties, which is often due to the yield reducing mungbean diseases that include Cercospora leaf spot and powdery mildew. Therefore, this collaborative project of partners based in India (BHU and OUAT) and RRes will tackle the these two most economically damaging fungal diseases. We will take an integrated approach that will involve the most up to date genetics (study of genetic variation) and genomics (study of genetic material) tools will be employed to aid development of new mungbean varieties that have improved disease resistance. We will characterise the genetic composition using DNA sequencing technology of both the fungal pathogens responsible for these diseases and mungbean varieties that will allow us to pinpoint the regions of the DNA that contribute for pathogenicity (causes disease) and for disease resistance of the pathogens and the plant, respectively. Using this knowledge, we will use state of the art biotechnology tools to engineer broad spectrum, and likely durable disease resistance into new varieties. Therefore, the results of this project will provide us a wealth of novel fundamental information on how the disease-causing fungus interacts with the mungbean plant, will help inform the best disease management strategies and help plant breeders to produce disease resistant mungbean varieties.

Mungbean, together with other pulses, serves as an inexpensive but highly important source of dietary protein, fibre, and minerals for people of India particularly for the vegetarian populations and the poor. Production of pulses in India, however, is unable to meet the demand of the growing population, where the Indian Government imports millions of US dollars-worth of pulses from other countries each year. Although high yielding mungbean varieties have recently become available, Indian farmers generally see less than half of the pulses yield potential from these varieties due to abiotic and biotic stresses such as diseases. Fungal diseases, such as Cercospora Leaf Spot (CLS) and powdery mildew (PM) can result in between 40-100% crop loss depending on weather conditions and due to the majority of farmers unable to afford fungicides. Our project will aid development of disease resistant mungbean varieties, which will allow Indian farmers to produce a more stable and improved mungbean yield thus contributing to farmers' wealth as more grain can be produced and sold, reducing the economic burden of India's economy as less grain would need to be imported, and provision of more staple food crop for the people of India. This project will, therefore, deliver fundamental research impacts as well as social and economic impacts.

Academic researchers in various fields will benefit from the project. This includes evolutionary and population biologists, plant geneticists, legume scientists, biotechnologists, scientists studying mechanisms of fungicide resistance and more. Publicly and privately owned breeding companies will benefit as well, as genetic markers generated over the course of the project will enable accelerated mungbean breeding pipelines. The project will also likely to have a political impact as GM (HIGS) and genetically edited (mlo) mungbean lines will create an important source of CLS and PM resistance for breeding programs as well as promote debate among policy makers and members of public on acceptance and regulation of GM, and genetically edited crops in India, UK and beyond.

The project will create an enormous potential for training of researchers in both UK and India, strengthening of academic bonds (e.g. via organisation of mini-Workshops) and knowledge exchange between the two countries. The project is expected to make a positive contribution towards strengthening food security, generating wealth among farmers, eradicating poverty and increasing awareness of the power of modern plant breeding technologies in India and rest of the world.

Various impact activities have been designed to maximise this project's outputs through engagement across the three years. Some public engagement and/or press release activities envisaged will require further training of PDRA and junior research team members. The various impact activities to be completed include developing and maintaining a project website featuring a map of fungal disease across all major mungbean growing regions if India, release of completed next generation sequencing datasets, visits to and continuing engagement with Indian farmers and farming advisors, a project dissemination mini-Workshop in India, presenting project findings at agricultural events such as Cereals in the UK and AgriFest in India, attending and presenting research findings at national and international conferences, publishing high impact articles available immediately via open access, preparing press release materials, and helping to train and enthuse the next generation of India and UK scientists.