Inkorporacija gena čvrstine ploda paradajza (Lycopersicon esculentum Mill.)

Tomato fruit firmness is a polygenetic trait and depends on firmness components pericarp thickness, firmness of epidermis and firmness of flash. The accumulation of favourable traits ratio for each component (towards the increase of expression) the fruit firmness can be increased. This paper deals with aspects of increasing fruit firmness by increasing firmness of epidermis and thickness of pericarp. By using genotypes with rin (ripening inhibitor) gene, we were able to accomplish great firmness of fruits, especially firmness of flash. The expression of these traits cause the asynchronization of maturing process so the fruits do not over mature or soften. Genetic effects have been evaluated by researching the average values of fruit firmness in six diallel parent lines (D-150, S-49, S-35, H-52, Kg-z and SP-109) and progeny (P1, P2, F1, F2, BC1 and BC2) by applying additive dominant model with three and six parameters (Mather and Jinks, 1982). Mean values of fruit firmness for parents and progeny were significantly different. Firmness of fruits is a trait influenced first of all by additive gene since they were found in all researched combinations. Epystatic gene effect was important in inheriting process for all three two-gene interactions. The stabile duplicate type of epystsase was found, which in this case reduces the unfavourable effects of dominant genes of parents with soft fruits. .Selekcija paradajza u pravcu povećanja čvrstine mora da uključi selekciju na debljinu perikarpa, čvrstinu pokožice ploda (kutikilarnog sloja ploda) i čvrstinu mesa. Čvrstina ploda predstavlja poligeno svojstvo i zavisi od komponenata čvrstine koje pojedinačno uslovljavaju ovo svojstvo. U ovom delu radu ispitivani su aspekti povećanja čvrstine ploda na bazi povećanja čvrstine pokožice i debljine parikarpa. Korišćenjem genotipova koji imaju rin (ripening inhibitor) gen, može se ostvariti velika čvrstina plodova i to sa aspekta čvrstine mesa. Na osnovu dialela šest roditeljskih linija (D-150, S-49, S-35, H-52, Kg-z i SP-109) i prosečnih vrednosti čvrstine generacija potomstva (P1, P2, F1, F2, BC1 i BC2), primenom aditivno dominantnog modela sa tri i šest parametara (Mather i Jinks, 1982) procenjeni su genetički efekti. Na nasleđivanje čvrstine ploda utiču prvenstveno aditivni geni jer su utvrđeni u svim ispitivanim kombinacijama. Dominantni genski efekti javljaju se u određenom broju ukrštanja, što ukazuje na njihov značajan uticaj. U nasleđivanju veliku ulogu igraju epistatični genski efekti sva tri tipa dvogenskih interakcija i utvrđena je pojava duplikatnog tipa epistaze u stabilnom obliku.