Evaluation of pea (Pisum sativum L.) germplasm for winter hardiness in Central Anatolia, Turkey, using field and controlled environment

Winter pea can be grown in rotation with cereal crops in Central Anatolia, Turkey. However, winterkill can occur during harsh winters. The objective of this study was to screen pea accessions for winter survival, and identify genotypes with differential winter hardiness for future crop development. The plant material consisted of 58 accessions including local landraces, elite winter cultivars, selected lines and several checks. Twenty-five of them were evaluated under both field and laboratory conditions. The rest of the genotypes were tested under field conditions. Field trials were planted in Haymana, Ankara, and in Ulaş, Sivas, Turkey during the autumn of 2014. Winter hardiness was evaluated as the percentage of surviving plants. Differential survival of genotypes was observed at both locations. On average, the survival rate was lower in Ulaş (54.8%) than in Haymana (67.8%), and ranged between 1.5 and 100%. Turkish landraces TR 79404 (88.6%), TR 79407 (88.5%) and TR 80194 (84.8%) had survival percentages comparable with the three winter-hardy checks (Turkish cvs. Taşkent (90.0%) and Özkaynak (85.0%), US cv. Melrose (94.7%)). Twelve single plants were selected from these populations for future cultivar development. The European and US accessions, included in the trials for their previously reported winter hardiness, showed high levels of winter hardiness, and could be used in breeding programs. In the laboratory, no plants survived at -12°C and -16°C three weeks following the freezing test. Screening at -8°C generated differential survival among winter genotypes. Significant positive correlations (r = 0.67-0.87, P < 0.001) were found between the test environments for the percent survival.