Determination of Stoma Characteristics and SPAD Values of Some Local and Commercial Grape Varieties Cultivated in Kayseri Ecological Conditions

Abstract This study was carried out to determine the leaf stoma characteristics and SPAD value of total 18 grape varieties (10 local and 8 commercial) grown in the Kayseri region. Among the varieties SPAD value ranged from 29.23 (Çekirdeksiz) to 42.26 (Kara Burcu), and the stoma frequency (stoma/mm2) ranged from 85.99 (Kara Burcu) to 136.83 (Tarsus Beyazı). Although there was a positive correlation between stoma width and stoma length, these parameters did not show a statistical correlation with stoma frequency. Stoma frequency and stoma surface showed a high positive correlation with both potential conductance index (r=0.76 and r=0.53, respectively) and relative stoma frequency (r=0.75 and r=0.65, respectively). Stoma shape coefficient showed a negative correlation with potential conductance index (r=-0.28). In this study, it was determined that the effect of the grape varieties on leaf stoma characteristics and SPAD value was important statistically. This result shows that leaf stomatal characteristics and SPAD value are genetically controlled.