New screening method for wilt resistance in chickpeaJuly 31, 2011 at 12:08 pm | Posted in Uncategorized | Leave a comment
ICARDA scientists have developed a new screening method to develop chickpea varieties resistant to fusarium wilt, a soilborne disease that causes severe yield losses. The disease is already widespread – and future outbreaks will likely increase as a result of climate change (higher temperatures, drier soils, and probably more rapid development of new races of the disease-causing fungus).
The most effective way to control fusarium wilt is by using resistant varieties. To develop such varieties, genotypes are traditionally screened in a ‘wilt-sick plot’ that is naturally and/or artificially infected with the fungus. But this method has a number of difficulties: development and maintenance of uniform wilt-sick plots, presence of multiple races of the fungus in the same plot, and the confounding effect of drought.
ICARDA scientists have optimized a hydroponic method to increase the accuracy of in vitro screening in a glasshouse. A number of genotypes were screened against a single race, in a glasshouse at ICARDA’s Tel Hadya research station, to examine the type and effectiveness of resistance. The genotypes ranged from highly susceptible (Syrian variety Ghab 1, which starts wilting 10 days after inoculation) to tolerant (Indian variety JG-62 which begins wilting only at the flowering stage) to completely immune (WR315).
The new screening method is more cost effective and accurate than traditional methods, and also allows breeders to screen simultaneously for resistance to multiple races. Based on the same principle, a high-throughput screening platform will be established that could be used to screen for resistance to multiple diseases. This method will also help identify different gene(s) conferring resistance to different races of the wilt pathogen; and enable breeders to combine multiple genes into a single variety through DNA marker-assisted selection.