Biological characteristics of grafted eggplant on tomato rootstocks

Abstract

Grafting eggplant (Solanum melongena L.) on tomato rootstock is an effective method to control Verticillium wilt (caused by Verticillium dahliae), a soil-borne disease. This study investigated the fruit quality and biological characteristics associated with disease resistance of eggplants grafted onto tomato rootstocks ‘Lydl’. The plant height, stem diameter, leaf area and root volume of grafted eggplant were higher than those of non-grafted eggplant. And the increase rates were up as the date prolonged. The root active-absorbing area, chlorophyll content and peroxidase (POX) and phenylalanine ammonialyase (PAL) activities of grafted eggplants were higher than those of non-grafted eggplants, while the comparative conductivity and the free proline content decreased by 42.42 and 44.08%. Obviously, grafting on tomato rootstock improved the growth and development of eggplant. The soluble sugar, vitamin C and protein content in fruit of grafted plants were not lower than those in non-grafted ones. Fruit qualities were not significantly affected by grafting. At the all three sampling stages, grafted plants showed higher amounts of bacteria and actinomyces, total microbial population, and the ratios of actinomyces to fungi (A/F), bacteria to fungi (B/F) and microbial biomass (MBC, MBN, MBP, MQ), but lower fungi population. The activities of urease and catalase in rhizosphere were enhanced by grafting. Grafting could modify the plant growth and microbial characteristics which may enhance the resistance to Verticillium wilt. Key words: Verticillium wilt, grafted eggplant, microbial property, microbial biomass.