Evaluation of 22 populations achieved from controlled crossing between some seeded × seedless grapevine cultivars

Grapevine is one of the most important fruit crops in the world. A program for the producing new table and raisin grape cultivars was started with evaluation of 90 cultivars which ended up to selection of six superior seeded cultivars as female parents and four seedless cultivars as male parents. In this study, 381 progenies originating from 22 cross combinations were evaluated when they were five and six years old during 2006 and 2007. According to seed or seed trace fresh weight, progenies were classified into four classes including completely seedless, semi-seedless, semi-seeded and completely seeded. Average seed/seed trace weight (in four classes) were 10.88, 22.47, 33.59 and 48.55 mg, respectively. As a result, 42 genotypes (11%) were considered as completely seedless, 52 genotypes (13.6%) as semi-seedless, 92 genotypes (24.1%) as semi-seeded and eventually 195 genotypes (51.2%) as completely seeded.Proportion of seedless progeny for four seedless male parents consisting of “Askary”, “Yaghooti”, “Bidane Ghermez” and “Bidane Sefid” were 15.4%, 10.8%, 10.6% and 9.3%, respectively. Some seedless genotypes had desirable characteristics including large firm berries, early ripening, good berry attachment to rachis and thinned berries which were superior compared to commercial Iranian seedless cultivars. Heritability for berry length, berry weight and berry width was high (0.67, 0.65 and 0.54, respectively). Heritability of other traits such as ripening date, TA, TSS and TSS/TA was 0.60, 0.37, 0.29 and 0.28, respectively. Correlation coefficients of berry weight with °Brix and acid content was highly affected by genetic rather than environmental factors. Results showed that “Askary” as a male parent and “Tabarze” as a female parent were the best progenitors for producing new seedless genotype.