Storage-linked Physiological Characters of Tomato Carrying Fruit Ripening Mutant Genes and Their Implications in Breeding

Institute of Vegetable Crops,Jiangsu Academy of Agricultural Sciences, Nanjing,210014)Abstract:Respiration rate, ethylene production, polygalacturonase(PG) activity and firmness of tomato(Lycopersicon esculentum Mill) fruits were analysed with 3 fruit ripening mutants (alc, nor, rin),a normal tomato cultivar Dahongand their hybrids(F1). In fruits of the mutants ethylene and CO2 production were very low and no respiratory or ethylene climacteric was observed and their firmness declined very slowly with only traces of PG in mature fruits.They showed a 300% increase in storability compared to 524 Dahong, with a mean storage life of 60-90 days.Fruits of the heterozygotes(alc×ck1,nor×ck1, rin × ck1) had insignificant respiratory and ethylene climacterlcs,which were delayed for about 5-7 days compared to that ofSu Kang No.5. Their peak ethylene production and respiratory climacterlc from harvesting at mature green to red colour was 40%-65% of that in normal ripe fruits. Their PG activity and firmnesslevels came between those of two parents. The F1 hybrid fuits had a slightly increased storage life compared tothat ofnormal cultivar(Sukang No.5).Their fruits cobur were qualitatively similar to those of cultivarSukang No. 5fruit.Changline,an outstanding F1 hydrid with long shelf-life, high disease resistance and high yield, has been derived with the nor mutant as one of its parents.Efforts are also being made to use the alc mutant in tomato breeding.