Research Scientist Geneshifters Pullman, Washington
Body of Abstract: Ascochyta blight is an important pathogen impacting global chickpea production. Systematic evaluation of the cultivated chickpea germplasm has identified few sources of resistance providing only partial resistance, most of which have already been exploited. Wild relatives of chickpeas represent a source of untapped variation for many value-added traits including biotic and abiotic stress tolerance. A very high level of resistance to AB has been reported in wild species including Cicer pinnatifidum, C. judaicum, C. bijugum, and C. echinospermum. No practical method is currently available to transfer this high level of resistance in a precise and targeted manner. Currently, available methods to transfer value-added genes from wild un-adapted germplasm to cultivated chickpeas are cumbersome and generally result in the transfer of a whole chromosome, arm, or large chromosomal segments that carry thousands of undesirable genes. This is due to the presence of strict chromosome pairing and recombination control. Because of the stringent homoeologous chromosome pairing control, chromosomes of wild relatives do not pair or recombine with the chickpea chromosomes during alien introgressions resulting in the transfer of whole chromosomes/arms or large segments that almost always carry unwanted traits (linkage drag). Thus, a targeted alien gene transfer method is required to transfer value-added genes such as that for AB resistance, in a targeted manner. We have identified novel accessions from wild chickpea germplasm, which we are using to optimize a novel method of alien gene transfer using virus-induced gene silencing for the targeted transfer of ascochyta blight resistance. We have successfully developed F1s between cultivated and wild chickpeas while initial optimization of virus-induced gene silencing using the PDS gene gave positive results. An update will be presented during the meeting if the abstract is selected for oral presentation.