Update: Ascochyta-resistant chickpeas by Michael Materne, Ted Knights, Kevin Meredith, Trevor Bretag, JanBert Brouwer and Wayne Hawthorne
THE VICTORIAN, NSW and SA collaborators in the GRDC-initiated National Chickpea Improvement Program are cOnimercialising the first Ascochyta blight-resistant chickpea varieties for growers this year. The first of the Ascochtya blight-resistant desi chickpea varieties should be available to farmers in 2004, with kabuli chickpea varieties coming on line in 2005.
These varieties will significantly reduce the reliance on foliar fungicides and should help the resurgence of a major chickpea industry in southeastern Australia. Varieties with resistance to both Ascochyta blight and Phytophthora will further improve the reliability of chickpea production in northeastern Australia and help accelerate the expansion of the industry in that region.
Australian varieties range from susceptible to highly susceptible to Ascochyta blight and total crop failure is expected under favourable conditions for the disease, if good disease management practices are not followed. In south-east Australia, desi chickpea production is less profitable compared with other cropping options, due to the high cost of repeated fungicide applications.
In the more favourable areas of Victoria, kabuli chickpea production has increased as high grain prices compensate for the added cost of multiple fungicide sprays. In north-east Australia, Ascochyta blight has been controlled by good management practices promoted throughout the region. Ascochyta blight can be controlled with good fungicide strategies, however the reliance on fungicides may not be sustainable.
The only current cultivar with reasonable Ascochyta blight resistance is Howzat, a desi type that is moderately susceptible. In 1998 the NRE chickpea breeding team at VIDA, Horsham, selected a number of desi and kabuli lines having moderate to high levels of Ascochyta blight resistance. These lines included breeding lines from ICRISAT (e.g. ICCV96836) and ICARDA (e.g. FLIP94-508C, FLIP94- 90C, FLIP94-92C, S95362 and S95342), selections from existing Australian varieties (e.g. Heera, Sona, Barwon), and breeding lines.
A pedigree seed program was immediately initiated with a subset of these lines. To spread the risk, this work was split between the Horsham and Tamworth programs, with two generations per year to speed up the seed increase. This year the Tamworth chickpea breeding team identified Phytophthora resistance in some Ascochyta blight-resistant lines. Many of these lines have even better Phytophthora resistance than that of earlier released varieties such as BarwonJimbour and Howzat. It is planned to multiply these lines this summer.
The commitment of the GRDC, NRE, NSW Agriculture and members of the National Chickpea Improvement Program has enabled the rapid development of Ascochyta blight-resistant cultivars and a bright future for chickpea growers in Australia.