Australia
June 2010

Source: The Grower - COGGO newsletter Vol 10 Issue 24

Chickpea plantings in WA will target heavy-textured soils with subsoil salinity.

Chickpea is particularly sensitive to soil salinity, with even mild salinity resulting in foliar damage, growth reductions and depressed yields, according to University of Western Australia Professor Tim Colmer.

When COGGO, DAFWA, CLIMA and UWA breeding team members saw the apparent diversity in salt tolerance in a large screening of chickpea germplasm at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in India, they decided to obtain the most tolerant lines and test them under WA conditions.

COGGO, CLIMA and ICRISAT successfully developed a project, ‘Accelerated genetic improvement of desi chickpea for WA’, funded by the Australian Research Council
(ARC), in partnership with COGGO.

In addition to bringing new chickpea germplasm for WA and evaluating it under WA conditions, attracting ARC funds also enabled researchers to address the physiological
reasons for salt sensitivity in chickpea and develop molecular markers for salt tolerance.

This knowledge and anticipated molecular markers will facilitate future breeding efforts to incorporate improved salt tolerance into elite cultivars. A large screening experiment at UWA in replicated pots of soil from the WA grainbelt, with salt added to impose well defined salinity levels, has confirmed that several lines identified by ICRISAT have superior salt tolerance.

These lines out-performed the historical WA check varieties, Sonali and Rupali, previously successful cultivars prior to Ascochyta devastation of the WA industry. Several ICRISAT lines even outranked CSG8962, a salt tolerant cultivar available in northern India.

Genesis 836, a released cultivar with moderate Ascochyta tolerance, also appears to be salt tolerant and may prove a good parent for future breeding if 2009 results are
repeated in 2010. The 57 lines were also evaluated in small-scale field trials on salt affected land on COGGO Chairman Bruce Piper’s Bindi Bindi farm. Plants (one metre
single rows) were regularly sprayed to avoid Ascochyta damage, in order to evaluate plant phenology and field performance without the complication of disease at this stage. Seven lines out-yielded Sonali and work in 2010 will evaluate priority lines in small field plots to obtain true yield data. The best lines will be used as parents in the
DAFWA/CLIMA/ICRISAT/COGGO chickpea breeding program, so that improved salt tolerance is crossed into the Ascochyta resistant
materials.

Salt Damage

The physiological and molecular basis of salinity tolerance is being determined in collaborative work between ICRISAT and UWA. Salt damage likely occurs due to accumulation of high levels of chloride in shoots. The reproductive stage is even more sensitive to salinity than vegetative growth.

Two populations of recombinant inbred lines from crosses between two different salinity tolerant and two salinity sensitive parents, have been developed at ICRISAT. These populations have been screened for salt tolerance, measured as grain yield under saline conditions, and are currently being ‘genotyped’ in order to identify molecular markers for salinity tolerance in chickpea. If strong markers are identified, this enables potential future marker-assisted selection (MAS) in breeding. MAS would enhance the capacity to cross salt tolerance into elite breeding lines, as screening for salt tolerance is time-consuming and variability in saline fields poses a challenge for screening large numbers of lines. The project is poised at an exciting stage, with the best bet lines to be evaluated in yield plots in WA in the 2010 season and the initial molecular maps of salinity tolerance in chickpea likely to be available by the end of 2010.

The project started on January 1, 2005 and Phase I finished on December 31, 2009. A three year extension to take the project to Phase II started on January 1, 2010 and is scheduled to finish on December 31, 2012. In the past five years more than 4000 new breeding lines have been developed. More than 2500 of these have been imported into WA. A large number of very promising lines with high level of Ascochyta resistance have now been identified for Crop Variety Testing in WA and for the National
Variety Trials in future.

Website: http://www.coggo.net.au

Published: June 11, 2010