Potential agronomical and biochemical selection criteria for resistance to cold in some annual Vicia L.

Most of the production areas of faba beans (Vicia faba L.) in the world are globally affected by biotic and abiotic stresses. Drought accompanied by heat stress is one of the most important prevailing stresses in the world including the Mediterranean region. To overcome drought accompanied by heat stress in the region, faba bean is traditionally sown in autumn and grown during winter as food and feed crop. It can only be grown in winter with cold tolerant cultivars at highland areas. Autumn-sown faba beans have some advantage over spring ones such as high seed yield and avoid some pests. The present study was aimed to (i) screen and select cold tolerant genotypes of faba bean; (ii) to compare faba beans to wild species for cold tolerance in the highland of the west Mediterranean region, Turkey; (iii) and to determine potential agronomical and biochemical selection criteria in cold tolerant and susceptible genotypes.A total of 114 accessions of Vicia species including 109 genotypes of faba bean, three genotypes of narbon bean (V. narbonensis L.) and two genotypes of V. montbretii Fisch. et C.A. Mey. were screened for cold tolerance at seedling stage in two successive years, 2005?2006 and 2006?2007 growth seasons. Accessions were evaluated for cold tolerance using a 1 (Highly cold tolerant)-5 (Highly cold susceptible) visual scale.Considerable variation was found for cold tolerance and some agronomical characteristics in faba beans. Wild relatives of faba bean were found to be more tolerant to cold than those of the cultivated faba beans. Although some pigmented genotypes were free from freezing damage at -9.6 oC without snow cover, accessions with white flowers were damaged.Seed weight was the least affected characteristic by different year and having the highest broad sense heritability, and it should be used in early breeding selections. When breeding cold tolerant faba beans, path and multivariate analyses showed that biological yield should be evaluated ahead of many other agronomical characteristics. Also, biological yield and harvest index for increased yield should also be considered.The genotypes ACV 46-2 and ACV 62 were selected for high seed yield, whereas ACV 49, ACV 51 and ACV 53 were selected for high pod number per plant. ACV 49, ACV 51 and ACV 53 will be evaluated as vegetable.The genotypes ACV 42 and ACV 84 in faba bean and the genotypes AWV 1 and AWV 2 in narbon bean were selected as cold tolerant genotypes, while the genotypes ACV 51, ACV 54 and ACV 84 in faba bean were found as cold susceptible. These genotypes were further evaluated for biochemical selection criteria after they were exposed to cold at highland (Urkutlu) and cold free (warm) conditions at lowland (Antalya). Jasmonic acid, xilose, fructose, glucose, sucrose and total sugars in cold tolerant and susceptible genotypes were investigated as potential biochemical selection criteria in both cold and warm conditions. In general, the potential biochemical selection criteria were found to be higher in genotypes grown in cold treatment (Urkutlu) than those of cold free conditions (Antalya). All these biochemicals were generally detected at higher level in genotypes of narbon bean than those of faba beans. It was concluded that jasmonic acid and free sugars determined in the present study were significantly increased when genotypes were subjected to cold. Results suggested that the increased at the level of jasmonic acid and free sugars could be based on protection mechanisms for cold tolerance in Vicia species. It was postulated that fructose could be considered as a potential biochemical selection criterion for cold tolerance because fructose was statistically and significantly correlated with cold tolerance.