Identification of groundnut genotypes resistant to iron deficiency chlorosis
Groundnut (Arachis hypogaea L.) is the second most important oilseed in India, which is mainly grown in states like Gujarat, Andhra Pradesh, Karnataka, Tamil Nadu and Maharashtra. More than one-third of the soils in India are calcareous and spread mostly in the low rainfall areas of the western and central parts of the country where groundnut is a major crop. As calcareous soils are deficient in available iron (Fe2+), iron deficiency chlorosis (IDC) is more prevalent in Saurashtra region of Gujarat, Marathwada region of Maharashtra, and parts of Rajasthan, Tamil Nadu and Karnataka causing significant reduction in yield (Singh et al., 2004). Iron deficiency leads to interveinal chlorosis of younger leaves, while under severe deficiency they turn into white and papery and further as brown and necrotic. Genetic variability for resistance to IDC has been reported earlier in groundnut (Samdur et al., 2000; Li and Yan-Xi, 2007). Cultivation of IDC resistant cultivars in calcareous soils is economically feasible and sustainable approach compared to application of iron containing fertilizers through soil or foliar spray.