Evaluation of Freezing tolerance of deci-type chickpea genotypes (Cicer arietinum L.) in Mashhad climate conditions

Low yield and instability, is one of the most important issues in chickpea cultivation. In most regions of Iran, chickpea is mainly planted in spring. Consequently, the plant will be exposed to abiotic stresses such as heat and drought during growth season, especially during the final stages of growth. To increase the chickpea yield, Autumn planting can be used, but low tolerance of common chickpea genotypes to freezing stress is a problem. Therefore, according to the benefits of autumn planting of chickpea, identification of freezing tolerant genotypes of chickpea along with suitable yield is a necessity. In this way, the present study was conducted as a field experiment to assess winter tolerance of 29 deci- type chickpea genotype in Mashhad conditions.

Experiment was conducted as Complete Randomized Block Design with three replications and 29 deci-type chickpea genotypes in research station of Faculty of Agriculture, Ferdowsi University of Mashhad in 2016-2017. Genotypes were supplied from seed bank of Research Center for Plant Sciences, Ferdowsi University of Mashhad and seeds were planted in November 1st. The lowest minimum daily temperature during the growing season was -13ºC. To calculate survival percentage, number of plants werfor each genotype was recorded 30 days after emergence and on March 15th. At the end of the growth season, plant height, number of main and secondary branches, pod number per plant, 100-seed weight, seed weight per plant, seed yield per square meter, biomass, biological yield and harvest index were measured.

significant differences were found among genotypes according to all the studied traits. While only one genotype was entirely killed as a result of freezing stress, survival range differed between 8-100% for the other genotypes. Among all 29 deci chickpea genotypes, 11 genotypes were tolerant (76-100% survival) and five were relatively tolerant (51-75% survival). MCC890, MCC349 and MCC873 had the highest winter survival with 98.1, 95.7 and 95.2%, respectively. In total, 9 genotypes including MCC373, MCC884, MCC869, MCC916, MCC349, MCC386, MCC870, MCC291 and MCC876 produced high yield of 154g.m-2 (equivalent to 1540 kg.ha-1) and all of these genotypes had higher survival percentage than 66.7%, except MCC916. Significant positive correlation were found between seed yield and survival percentage (r=0.76**), number of secondary branches (r=0.23**), pod number per plant (r=0.52**), 100-seed weight (r=0.38**), biological yield (r=0.59**) and harvest index (r=0.58**).

According to the results of the present study, it seems possible to achieve cold tolerant deci chickpea genotypes for cultivation in cold regions. Based on cluster analysis, two groups of genotypes including 1) MCC10, MCC49, MCC207, MCC890 and 2) MCC868, MCC918, MCC884, MCC386, MCC291, MCC349, MCC916, MCC373 can be used in breeding programs due to their superior attributes such as early- season cold tolerance.