Selection for water-use efficiency in food legumes

• National Research Centre for Groundnut, India
• Australian National University, Australia

Drought is a major factor limiting yields of peanuts in India and other semi-arid tropical (SAT) regions including Australia. India produces nearly one-third of the world's peanuts (6 million tonnes produced annually from 7 million hectares) and one-quarter of the world's pulse crops (including chickpeas and cowpeas).

The majority of the crops are grown under rainfed conditions and drought frequently reduces yields by 30-60% depending on season. In Australia, most crops are also grown under rainfed conditions. Compared to world figures production is low, however, production of pulse crops has risen dramatically reflecting the importance of these crops in Australian farming systems.

Research scientists at ICRISAT and the Indian Council of Agricultural Research (ICAR) will screen the world germplasm collection and genetic material in applied peanut breeding programs, to identify lines with high W (via the correlated trait of SLA) and high HI characteristics.

The objectives of this project are:

to identify and select peanut cultivars with high water-use efficiency (W) and biomass partitioning characteristics from the world germplasm collection (held at the International Crops Research Institute for the Semi-Arid Tropics, [ICRISAT], India) and genetic material from applied peanut breeding programs;

to evaluate the yield performance of parent lines or progenies in appropriate target environments in India and Australia; and

to determine the extent of cultivar variation in W, its correlation with and harvest index (HI) and the relationship of these traits to seed yield in soybean, cowpea, chickpea, and navybean.

ICAR plant physiologists/breeders will grow the selected lines under water-stressed conditions at six locations in India with differing drought patterns. They will measure total dry matter, pod yield, phenology, light interception, SLA and HI and analyse the data to determine the influence of W on pod yield as compared to other adaptational traits. A subset of the cultivars will be analysed by scientists at the Australian National University (ANU) to check that the relationship between SLA and W is maintained. Further experimentation to determine the optimum sampling methodology for SLA will also be conducted in both India and Australia.

In India, scientists from the Crop Physiology Department of the University of Agricultural Sciences, Bangalore, will conduct glasshouse and field studies on genotypic variation of W in cowpea and chickpea. Similar studies on soybeans and navybeans will be a carried out in Australia by scientists at the Department of Primary Industry Research Station at Kingaroy in Queensland.

For the soybean research close collaboration with the ACIAR-funded project Soybean Improvement in Thailand (PN 9040), where genetic variation in a number of traits possibly related to W, such as epidermal resistance and osmotic adjustment, are being studied.