Additional Sources of Tolerance to Cold in Cultivated and Wild Cicer Species

Cold tolerance is an important prerequisite for winter sowing of chickpea (Cicer arietinum L.) in Mediterranean environments. Cold-tolerant lines identified earlier at ICARDA are sometimes not tolerant enough to tolerate exceptionally cold winters which occur occasionally. The objectives of this study were to identify sources of increased cold tolerance and to ascertain associations of cold tolerance with other plant traits. Cold tolerance of 4284 kabuli and 2137 desi germplasm lines, 857 breeding lines, and 59 lines of seven annual wild Cicer species was evaluated during the five winters from 1987 to 1992 at ICARDA sites at Tel Hadya and Breda in Syria. The susceptible check was killed in all 5 yr, indicating the severity of cold winters. Eleven kabuli but no desi germplasm lines, and 14 breeding lines, were tolerant. Among the cultigens, a germplasm line (ILC 8262), a mutant (ILC 8617), and a breeding line (FLIP 87-82C) were the best sources of cold tolerance, with a consistent rating of three (1-9 scale, where 1 = free from damage and 9 = all plants killed) over years and locations. Among wild species, 26 lines of C. reticulation, 10 of C. bijugum, four of C. echinospermum, two of C. pinnatifidum, and one of C. judaicum were cold tolerant. Five lines of C. bijugum and four of C. reticulatum had a rating of two, reflecting their better cold tolerance than the cultigen. Correlation studies on 2970 lines indicated that prostrate growth habit during winter months was positively associated with cold tolerance. Some late-flowering lines were susceptible, others were tolerant to cold; whereas, all early-flowering lines were susceptible to cold. Cold tolerance had no association with anthocyanin pigmentation on the stem. Older plants were more susceptible to cold than younger plants. Joint Contribution from ICARDA, and ICRISAT (Intl. Crops Res. Inst. for Semi-Arid Tropics), Patancheru P.O., A.P. 502 324, India.