Assessment of chickpea genotypes for high temperature tolerance

Global warming is predicted to increase temperature by 5°C by the end of this century. Scope of expansion of rice fallows, changes in cropping system and the global warming demand identification of chickpea varieties tolerant to high temperature. With this objective plants of 115 chickpea genotypes comprising released varieties differing in their sensitivity to temperature were grown under two sowing dates normal (November 18, 2009) and late (December 12, 2009) in order to assess their tolerance against high temperature (>35°C) by studying various morpho-physiological traits. In general, results indicated that high temperature caused hastening of flowering and maturity in chickpea by 15 days in late sown as compared to normal sown conditions. Canopy temperature depression (CTD) and relative stress injury (RSI %) exhibited significant differences among the genotypes. Under normal sown conditions, CTD values ranged from -2.9 to -7.2°C in RSG-2 and GNG-146, respectively. Similarly, under late sown conditions, the values ranged from -1.8°C in Vaibhava to -4.8°C in GNG 663. Relative stress injury of leaves varied from 20% in CSG 8962 to 42% in Pusa 244 under normal sown and from 23% in GNG 663 to 50% in Pusa 244 under late sown conditions. The genotype Pusa 244 experienced highest reduction (70.4%) in seed yield plant⁻¹ while lowest was (7.3%) in GNG 663. The chickpea genotypes Pusa 240, JG 218, ICCV 92944, RAU 52, HK 94–34, KWR 108 having low HSI, RSI and high CTD values found place on the negative end of principal factor 3 and 4 were identified as thus showing thermo-insensitive the maximum tolerance against heat stress under late sown conditions. In addition to above, chickpea genotypes IPC 98–12, CSG 8962, GCP 101, CSJD 844, GNG 146, M2, ICCV 4958, Pusa 209, Pusa 267, BG 276 and GNG 663 also had low HSI values but with higher values of RSI and CTD. Therefore, it is concluded that these genotypes in future may prove better for developing heat tolerant genotypes and can be used in hybridization programme of chickpea.