| In this study, we investigated the agronomic traits of the germplasm resources of tomato stock introduced from abroad and their bacterial wilt disease resistance under the condition of subtropical climate. Furthermore, we conducted grafting experiment on high resistance stocks to study their grafting and symbiotic compatibility with local cultivar scions. Our study aims to prepare germplasm resources for further study of tomato inheritance of resistance and also for breeding of hybrid varieties which have bacterial wilt disease resistance also accustom to the subtropical condition.The main conclusions are as follows:1. In the area of south part of Guangxi Province, we conducted the adaptive cultivation for20germplasm resources of tomato stock. By comparing of several agronomic traits of all the stocks, we found that every stock grow well, blossomed and bore fruit normally, appeared highly adaptability; all stocks could collect seeds after self-cross, and the seeds germinated well,9stock-scion comparisons had over80%germination rate. The experimental germplasm resources of tomato stock showed certain botany characteristics diversity.2. The bacterial wilt disease resistance of these20germplasm resources of tomato stock was identified during their seedling stage in greenhouse, among them10highly resistance stocks,6resistance ones and2middle resistance ones were selected. Considering their agronomic traits,9of them were selected for the further resistance evaluation in climate chamber. The results showed that C, Q3, A were highly resistance, Kl, Q5, Q7were resistance, C7was middle resistance, F3was sensitive, and Y3was highly sensitive.3. The activity of plant defensive enzymes (antioxidases) in different cultivars after bacterial infection was studied. The results showed that the activity of peroxidase (POD) and polyphenol oxidase (PPO) in inoculated plant leaves significantly increased than that in non-inoculated plant leaves, and there was a positive correlation between the level of enzyme activity and disease resistance. So the activities of POD and PPO could be used as assisting index to evaluate tomato bacterial wilt disease.4. Highly resistance stock A and C were chosen for the grafting experiment with "0626","Hongbeibei" and "Fenbeibei". The grafting survival rate and the disease resistance of all the stock-scion combinations were compared, and the controls were the self root seedling.All the stock-scion combinations had over80%grafting survival rate, showing high grafting compatibilities. Different combinations had different compatibilities, stock A showed higher survival rate than stock C. Four combinations of stock A, C and scion "0626","Fenbeibei" were identified their bacterial wilt disease resistance, and the results showed that disease index of grafting combinations were significantly lower than the control. The grafting combinations had disease resistance effect, and stock A showed over40%effect while stock C showed nearly70%effect. Stock C showed higher disease resistance than stock A.At early stage of field planting, grafted seedling showed lower growing index like height, leaf number, inflorescence number than the control, however,45and60days after planting, there were no significant differences of the above index between most grafted seedling and the control. And the increasing rate of the growing index in grafted seedling was higher than the control, suggesting that grafting improve plant growth. The start of the blossom of grafted seedling was2-6days later than the control, and the total flowers in the1st-3rd inflorescence, fruit set rate, fruit weight, fruit shape index and soluble solid content of grafted seedling had no significant difference from the control. The early fruit yield of grafted seedling was lower than the control while the later fruit yield of grafted seedling increased. Stock C and scion "0626","Fenbeibei" had the total yield5.13%and5.39%higher than the control. Generally, there were no significant differences of the total yield between grafted seedling and the control. |
PDF Full Text Request