Sub-theme 1d - Improving flood tolerance to mitigate root disease
Waterlogging tolerance has received little attention, but the sensitivity of current chickpea varieties to excess water in the root zone is evident (Solaiman et al., 2007; Palta et al., 2010), as is the effect of transient or prolonged soil saturation on chickpea root diseases such as Phytophthora root rot (Murray & Brennan, 2012). This project will analyse the responses of a diverse set of chickpea germplasm to soil flooding to identify useful genetic diversity in tolerance of this stress. We will evaluate responses during soil waterlogging and capacity to recover upon subsequent soil drainage. Root traits, such as capacity of root tips and other tissues to survive hypoxic and even anoxic conditions, capacity for internal oxygen transport, tolerance of reduced metals (Mn2+, Fe2+), and ability of roots to resume growth when flooding recedes, will be evaluated, as well as plant growth and seed yields in longer term-experiments. Our laboratories are well equipped for studies of anoxia tolerance and oxygen transport (Malik et al., 2002; Garthwaite et al., 2003; Goggin & Colmer, 2005), and we will work jointly with Theme 1e to evaluate oxidative stress in roots during recovery from anoxia. Using genome wide association mapping approaches, we will determine genomic regions associated with tolerance. The identification of contrasting lines will eventually enable development of RIL populations by accelerated single seed descent if needed for gene cloning, and also guide the implementation of traits of relevance in chickpea breeding.
Genotypes with superior tolerance identified and available to breeders, priority physiological traits and genomic regions identified, mapping populations developed to provide a resource to enable future QTL analyses.