Graft-induced Changes in Skin and Flesh Color in Tomato (Lycopersicon esculentum Mill.)

Abstract

Induction of hereditary changes by grafting in tomato was reconfirmed by combination of the cultivar Jubilee (yellow skin-orange flesh) as scion and the cultivar Tiny Tim (yellow skin-red flesh) as stock.
The phenotypic change from yellow-orange (Jubilee type) to yellow-red (Tiny Tim type) was observed in the grafted scion (G₀) on the Tiny Tim stock. In the selfed progeny (G₁) from this Tiny Tim type variant fruit on the Jubilee scion, new type (colorless-red) was segregated in addition to Jubilee type (yellow-orange) and Tiny Tim type (yellow-red). The genotypic change of skin and flesh color is assumed to have occurred from Yyrr (yellow-orange) to YyRr (yellow-red) in the grafted scion and in the first self ed progeny, Y-R-(yellow-red), Y-rr (yellow-orange) and yyR-(colorless-red) were segregated from the YyRr variant (G₀). Most of the successive progenies (G₂ and G₃) obtained from the segregants in the G₁ generation accorded with Mendelian inheritance. But the phenotypic changes inexplicable in terms of Mendelism were assumed to have changed from yyR-(G₁) to Y-R-(G₂), from Y-rr (G₂) to Y-R-(G₃) and from yyR-(G₂) to Y-R-(G₃). But yyrr (colorless-orange) was not detected in all successive progenies. No other characters than skin and flesh color have been changed in the present study.
It is likely to suppose that the transmission of genetic material from stock to scion would have occurred, though the mechanism is quite obscure yet.