a study of some genetic parameters in table grape breeding program

grapevine is one of the very important fruit crops in iran the fruit of which is used as table grape and/or raisins. in this study, some genetic parameters (phenotypic and genetic correlation, heritability and repeatability), of some important traits in table grape (date of ripening, weight, length and width of berry as well as attachment to cluster strength) were evaluated. results showed high heritability for some traits; heritability being 0.65, 0.67 and 0.54 for weight, length and width of berry respectively. heritabilities were 0.60, 0.29, 0.37 and 0.28 for date of ripening, °brix, acid content and their ratio respectively. results regarding coefficient of correlation showed that correlation between berry weight and °brix as well as acid content was highly affected by genetic factors while phenotypic correlation being rather low. repeatability of traits was observed as high during the two years. it was 0.98 for berry colour, however, it was very low for traits related to fruit juice (tss, ta and tss/ ta).