Cold tolerance during early reproductive growth of chickpea (Cicer arietinum L): Characterization of stress and genetic variation in pod set

Most chickpea cultivars grown in regions where temperatures fall below 10 degrees C continue to flower but fail to set pods. Research was conducted to characterize cold stress in a subtropical northern Indian location, Hisar and to examine genetic variation in pod and seed set at low temperatures. Lines of various maturity groups were used so that phenological timing of stress differed with line. Flowering was therefore synchronized with a cold spell to evaluate tolerance. A substantial variation was found both in field and controlled environments. Two early maturing advanced breeding lines, ICCVs (ICCV = ICRISAT Chickpea Variety) 88502 and 88503, showed good pod set in cold spells, but seed growth in them was limited. Evaluation of the parents indicated possible contribution of a germplasm from the former Soviet Union, K 1189 (ICRISAT chickpea germplasm collection No ICC 8923), to cold tolerance. Based on experiments in controlled environments, it is suggested that (a) pod set can occur at night temperatures of 0-5 degrees C If daytime temperatures exceed 20 degrees C (b) seed development requires a higher threshold temperature than pod set and (c) 15/5 and 15/0 degrees C (day/night) thermal regimes are useful in preliminary screening of germplasm lines for cold tolerance. (C) 1998 Elsevier Science B.V. All rights reserved.