Evaluation of Genetic Diversity Among Clones of Different Seedless and Seeded Grapes Cultivars in Arak City by Morphological Characteristics

Background and objectives:
Grapevine is one of the most important fruit crops in Iran which is used as table grape and raisin consumption. Among producing countries of grape, Iran is ranked ninth globally and the grape production is estimated to be two million tons. Ampelography was utilized for evaluation of genetic structure in grapevine. Ampelography is the science of phenotypically identifing of grapevines to distinguish thousands of grape cultivars, without the aid of genetic markers. This study has been conducted to investigate of some seeded and seedless clones of grape cultivars in Arak city in order to identify desirable clones for the development and cultivation of them. In addition, the identification of clones and desirable cultivars based on investigation of different characteristics from botany and horticultural perspective can be used for germplasm preservation and grapevine breeding programs.
Materials and methods:
In this study, genetic variation among forty-nine clones of seeded and seedless grapevine belonging to Vitis vinifera species were evaluated based on fifty morphological characters of leaf, shoot, fruit and seed. These accessions were collected from different geographical sites in Arak city. Leaf and friuts samples were collected randomly from various parts of trees at normal fully mature of each accession. In order to evaluate of traits related to leaf, thirty leaves were selected randomly from each clone with three replications and the characters of them were recorded. To investigate the traits related to fruit, three bunches and thirty berries from bunch were chosen randomly from each clone with three replications and the characters of them were recorded.
Results: Preliminary results illustrated that some traits such as bunch weight, the number of berries in bunch, berry weight, total soluble solids percentage, titratable acidity percentage, seed fresh weight, seed dry weight and TSS/TA index have shown high variability among grapevine clones. The genotypes have been divided in two main groups according to the results derived from cluster analysis so that the seed cultivars were separated from seedless cultivars. Simple correlation analysis among eighteen main traits showed that positive correlations were detected among traits. The principle component analysis results revealed that the first thirteen components explained 85.38% of the total variation for studied accessions. The first five components which related to fruit and leaf explained about 59.43% of the total achieved variability. In PCA, fruit weight, fruit length, fruit diameter, fruit size simultaneously character related to seed such as seed fresh weight, seed dry weight, seed moisture percentage, seed dry matter percentage were predominant in the first components, indicating that they were useful for the assessment of grapevine clones characterization.
Conclusion:
Finally, the results of this study showed that there are high variability among clones of grapevine cultivars in terms of quantity and quality characteristics of fruit. Also, some clones belonging to seeded and seedless grape cultivars had desirable traits. Therefore, these clones can be used for commercial cultivation or utilization in grapevine breeding program to achieve desirable progeny. Among seedless cultivars, the maximum of berry weight (3.34 gr) has been estimated in sample 23 (Askary clone) which was collected from Hazaveh village of Arak city. Also, the maximum of berry weight (5.24 gr) is obtained in sample 40 (Shahani clone) among seeded cultivars. In general, the production of seedless grape with largest berry is important to table grape breeding and these results illustrated that with identification of grape cultivars and desirable parent selection for breeding programs, new seedless cultivars with large berry from crosses of seeded and seedless grapes can be produced.