Analysis of Screening Tools for Drought Tolerance in Chickpea (Cicer arietinum L.) Genotypes

Background: Chickpea is the third most significant food legume worldwide. While deeper rooting can increase water extraction, as it has been hypothesised for almost three decades. Therefore, understanding the regulation of leaf water losses in plant canopy, first when there is no water limitation and secondly when plants are progressively exposed to water deficit, are likely to be equally critical to roots for achieving high chickpea yield under terminal drought. Present study was carried out with an aim to evaluate the use of physiological traits such as canopy temperature depression (CTD) and chlorophyll content to determine drought tolerance of chickpea genotypes under varying environmental conditions. Methods: Trials were conducted in 2009-2010 and 2010-2011 growing seasons at Gachsaran agricultural research station situated located in south-western of Iran. Chickpea genotypes were planted in two sets (each set had 3 replicates) by using a RCBD under two supplementary irrigation and rain-fed conditions. CTD measurements were made by infrared thermometer which was focused to 10:1 meter and at late morning to early afternoon cloudless periods (11:00 to 13:00 hours). Leaf chlorophyll content was measured at flowering and grain filling stages by using of a Minolta SPAD meter on 5-8 flag leaves per plot. Result: The CTD results in emergence of fifty percent of inflorescence stage and CHL in grain filling stage had high significant differences. The significant and positive correlation of DI, K2STI, Ys, GMP, STI, MP, Yp, K1STI showed that these indices were more effective in identifying high yielding genotypes under both conditions and result showed that CTD and CHL have played important roles to search physiological basis of grain yield of chickpea and CTD and CHL can successfully use as a selection criterions in breeding programs.