Fruit heritability and the Effect of Pollen on Fruit Set of Some Tomato (Solanum esculentum Mill.) Accessions

In this study, the fruit heritability of 15 different accessions of Iranian tomato (Urmia, Gorgan, Kafshgiri, Sari, Rasht, Kurdistan, Kermanshah, Semnan, Shahroud, Zanjan, Varamin, Esfarayen, Neishabour, Sirjan, Hamedan) and fruit set through pollen grain source, were measured in in Kalaleh city of Golestan province in 2019. The experiment was conducted in a randomized complete block design with 15 populations in three replications (five plants per population). After pollination, the fruits were evaluated in the laboratory and their seeds were extracted and collected. Traits including number of fruits per plant, fruit weight, number of cells and number of seeds were evaluated. Phenotypic diversity, genotypic diversity, environmental diversity and general heritability of traits were calculated. The results showed that fruit weight, fruit length and number of locular cavity respectively with 200 g, 8.83 mm and 12 had the highest value in Varamin accession. In Kermanshah accession, the highest number of fruit seeds was recorded with 323 pieces per fruit. Kafshgiri accession, with a length of 3.33 mm and a fruit weight of 9.17 g, is one of the smallest fruits. Fruit weight, fruit length, number of locular cavity and number of seeds had high heritability from 88 to 92%. In all studied traits, the coefficient of genetic diversity was higher than the coefficient of phenotypic diversity, which showed less impact of environmental factors on these traits. The results also showed that the fruits obtained from the cross-pollination of different accessions (offspring from cross-pollination) had the lowest amount of fruit weight and number of seeds and the offspring from self-pollination had a higher amount. However, non-self pollen grains had no effect on fruit length and locular cavity. From the results of the present study, it can be inferred that the type of pollen grain can affect the quantitative characteristics of tomato seeds and fruits so that most traits in the cross-pollination had significantly lower values ​​than the self-pollination. In order to increase the production efficiency of tomato, pollination with self pollen grains should be considered.