Can wild chickpeas reduce the nematode problem in Australian crops

Date: 28 May 2015

Ms Ros Reen and Prof John Thompson compare methods to test chickpea and wheat lines for resistance to root-lesion nematodes. After the plants have grown for 18 weeks, the nematodes are extracted from the soil and roots, and counted under a microscope to determine which plant lines have reduced nematode multiplication.

A new international collaboration between Australia, the United States and Turkey is seeking to tap into the genetic potential of wild chickpea to create more resilient and nutritious varieties.

The international project is a collaboration between GRDC, CSIRO and the University of California, Davis (UC Davis), through its Innovation Lab working on Climate resilient chickpea—one of 23 such labs awarded under 'Feed the Future', USAID's global hunger and food security initiative. Other key collaborators in the project include Turkey's Harran and Cukurova Universities and the Ethiopian Institute of Agricultural Research.

Today’s cultivated chickpea (Cicer arietinum) originated some 10,000 years ago from the wild chickpea species Cicer reticulatum, which continues to grow in remote areas of Turkey.

Domestication and breeding of the chickpea over millennia has meant a gradual narrowing of the crop's genetic potential and diversity, and a reduction in its ability to deal with drought, disease, frost, salinity and pests. The gene pool of the original wild relatives of chickpea, however, has been found to contain many of the commercially valuable traits required to combat these problems.

For the Australian contribution to the project, researchers will be specifically interested in the genetic resistance of wild chickpea to the root-lesion nematode (RLN), a microscopic worm that feeds on and damages the roots of susceptible crop hosts, like chickpea and wheat, limiting the plant's ability to access soil water and nutrients, thereby stunting it growth and reducing yield.

The two species most common to the Australian grain regions are Pratylenchus thornei and P. neglectus; P. thornei is the most problematic species in the northern region.

“Chickpea can lose up to 20% yield through P. thornei, and chickpea/wheat rotations build up populations quite high in the soil, which is detrimental to the following crop,” says Professor John Thompson, crop nematologist at University of Southern Queensland.

“Such a high susceptibility is on account of modern chickpea's narrower gene pool—its wild relatives probably evolved to have resistance to species of RLN that were endemic to the regions in which they grow wild,” he says.

“This project is an opportunity to really sample the wild diversity that's useful for chickpea breeding, and to see whether there's any outstanding sources of resistance to P. thornei and P. neglectus,” he says. “After the lines have been grown through quarantine in Australia, our job will be to screen a few hundred of them for resistance to RLN.

Researchers will eventually cross the wild and cultivated varieties to develop improved genotypes and varieties for release to growers.

“It is hoped that the development of commercial varieties with higher levels of resistance to RLN, using traits from wild relatives, will be most valuable for the Australian grain regions where alternating chickpea and wheat crops are the preferred rotation,” Professor Thompson says.

Contact

Professor John Thompson, Crop Nematology, Centre for Crop Health
University of Southern Queensland
07 4639 8806
john.thompson@usq.edu.au

GRDC Project Code DAN00151

Region North