ABSTRACT
The population of bacterial physiological groups in tomato with different resistant to Ralstonia solanacearum was studied. The results suggested that endophytic bacterial communities and population in tomato variety changed with different resistant cultivars, different stages of tomato and seasons. It was con-ducted that the amount of ammoniation bacteria was the highest among the seven physiological bacterial groups. There were more ammoniation bacteria in high resistant tomato cultivars than that in high suscepti-ble cultivars. It may indicate that ammoniation bacteria played a key role in the occurrence of tomato bacte-rial wilt. In addition, the total amount of physiological bacteria in resistant cultivars was more than that in susceptible cultivars in different stages of tomato, and the tendency of changing displayed fluctuation. The average level of quantities of the ammoniation bacteria, nitrifiers bacteria, erobic nitogenfixing bacteria and desulphate reducer bacteria in summer were higher than that in winter, while the population of the sulphate reduced bacteria in winter was higher than that in summer. Furthermore, the amount of anaerobic bacteria was the least among them.
ABSTRACT
The dynamic of endophytic bacteria at different growth stage of tomato and use of these endophytic bacteria to control tomato bacterial wilt were studied. The results showed that endophytic bacteria could be found in the tomato seeds and their quantities reached the highest peak in the adult plants both in resistant and susceptible cultivars. The amount of endophytic bacteria in adult plants of resistant tomato cultivars was 2.43?10~5CFU/g FW in the root and 22.9?10~4 CFU/g FW in the stem, while the amount of endophytic bacteria in adult plants of susceptible tomato cultivars was 9.8?10~4CFU/g FW in the root and 13.4?10~4CFU/g FW in the stem respectively. Seventeen strains of endophytic bacteria from resistant cultivars and only seven strains from susceptible cultivars were found to be antagonistic to Ralstonia solanacearum. In addition, some strains of endophytic bacteria had the abilities of promoting tomato seed germination and controlling tomato bacterial wilt, among which, strain 5R and 3R had better control effect of 91.7% and 81.3% respectively.