Performing of the Winter Buds and Phloem Tissue in Grape Cultivars After Cold Applications

Abstract

This study was carried out to determine bud and phloem tissue damage rates after cold treatments in 12 different grape cultivars. The single-bud cuttings tested at -10 degrees C and -15 degrees C during 18 h in freezer. The study was conducted in two group; one group is related with the damage rates of the winter buds and phloem tissue, the second group tested in cold applied cuttings in the growing room to be determined of the cuttings performance. The damage ratio of the winter buds and phloem tissue was evaluated by the cross-sectioning method. Freeze-tested single-bud cuttings were forced to sprouting in the growing room condition. The sprouting rate (%), cluster per shoot (%), root and shoot length (cm), root scale (0-4), root number values, and basal callus formation rate (%) were determined in the cuttings. According to results; while 'Karaerik' and 'Ugni Blanc' cultivars showed the highest primary bud viability in -15 degrees C (83.3% and 78.3%, respectively); 'cavus' showed the lowest primary bud viability rates with 0.02%. The highest phloem viability at -15 degrees C was determined in 'Narince' (70.0%) and 'Alphonse Lavallee' cultivars (65.0%). In the growing room condition; the highest root number, root length, and root scale were determined as in 'Ugni Blanc' cultivar subjected to -15 degrees C. In this study; according to bud cross-sectioning and growing room results, the least affected cultivars by cold applications were found as 'Karaerik', 'Ugni Blanc', 'Cardinal' and 'Alphonse Lavallee' cultivars.