Tolerancia del garbanzo tipo "desi", a bajas temperaturas en etapas tempranas del desarrollo.

Introduction: In Mexico, chickpea cultivation takes place during the Fall-Winter cycle, and sometimes is damaged by low temperatures. Both, white "kabuli" type and brown chickpeas, "desi" type, are grown in the Bajio region. Method: Nine "desi" chickpea genotypes were exposed in two trials to low temperatures at two stages of development, germination and vegetative. Four of them were local varieties and five introduced genotypes from ICRISAT, India. In the first trial, the seed of the genotypes was germinated in boxes with sterile sand under two temperatures: 7.0 and 25 o C. The days to emergence were determined and afterwards the seedlings were measured, dried, and weighed. The second test consisted of exposing plants in stage of 7 to 8 compound leaves to a temperature of -4 o C for 60 minutes, with pre and post treatment of 20 min at 4 o C, subsequently they were placed under the sun for two hours; after this protocol, the damage to each individual plant was visually rated. Results: In the first trial, at 25 o C all genotypes germinated in five days (average germination 91.3 %), while at 7.0 o C germination was delayed until 20 days (average germination 80 %) and the percentage decreased differentially among genotypes. ICC 3287, an introduced material, showed the highest average germination under both temperatures 94.9 %, followed by the local cultivar Lerma 89.3 %. The plantlet and root lengths showed significant differences (p < 0.001) between temperature treatments, genotypes, and their interaction; low temperature decreased both characteristics. In contrast, dry weight was similar between temperatures, with significant differences (p < 0.001) among genotypes and for the interaction temperature by genotype. At both temperatures, ICC 1263 showed the highest dry weight followed by cultivar Lerma. In the second trial, ICC 6671 and Lerma show the least damage by low temperature at the vegetative stage. Conclusion: Three introduced genotypes and a local cultivar showed outstanding traits: ICC 3287 higher germination under both tested temperatures, ICC 1263 higher seedling dry weight at suboptimal temperature; ICC 6671 along with cultivar Lerma were tolerant to freezing temperature stress in the vegetative stage. [ABSTRACT FROM AUTHOR]