ナス属植物を台木とした接ぎ木トマトの生育および収量

Abstract

Tomato scions (Lycopersicon esculentum Mill. cv. Momotaro) were grafted on Solanum sisym-briifolium, S. torvum and S. toxicarium which are resistant to soil-born disease, and their graft compatibility, fruit yield and temperature effect on the growth of grafted plants were compared with tomato grafted on its own roots, a tomato/tomato, scion/rootstock combination.Graft compatibility between tomato (scion) and three Solanum (rootstock) was excellent, achieving a success rate of 100%.The growth of the tomato grafted on S. sisymbriifolium was almost equal to that of tomato/tomato. Tomato/S. torvum and tomato/S. toxicarium grew slowly after grafting until the main shoot was pinched: they grew vigorously thereafter, suggesting a high symbiotic graft affinity.Fruit yield of tomato/S. sisymbriifolium was almost equal to that of tomato/tomato. Fruits of tomato/S. torvum were small and the yield smallest compared with the other scion/rootstock combinations. In tomato/S. toxicarium, fruit yield was about 80% of that of tomato/tomato in the spring crop, whereas their yields were nearly equal in the fall crop with the standard fertilizer application. Over- and under-application of fertilizer, however, caused lower yield in tomato/S. toxicarium than in tomato/tomato. Difficulties in adjusting the amount of fertilizer for the tomato/S. toxicarium were encountered.Photosynthesis rate was higher in tomato/S. sisymbriifolium than in tomato/tomato, indicating the wide range of tolerance to temperature in the former scion/rootstock combination. In tomato/S. toxicarium, photosynthesis rate was slower than in tomato/tomato. Tomato/S. toxicarium grew well at a narrow range of temperature, and, therefore, its vegetative growth was extremely poor at low winter temperatures.