Research Of Detection And Induced Resistance To Melon Bacterial Fruit Blotch In Xinjiang

Melon bacterial blotch( Acidovorax avenae subsp.citrulli) is one of the most important and destructive diseases of muskmelon and edible seed-watermelon in Xinjiang, after it is introduced Xinjiang from abroad. It is a quarantine disease that can be spread farther by seed, therefore ,it is very necessary to scan a rapid, credible, sensitive and systemic detected technology. Bactericide is usually adopted to control Acidovorax avenae subsp.Citrulli. But, excessive bactericide affect seriously quality of the melon fruit and ecological environment. In order to improve the plants resistance, especially, to advance the plants system acquire resistence (SAR), it is the important value in academic and practical. Forther ,scaning resistant varieties is one of the perferable methods to control melon Bacterial Fruit Blotch.Through experiment for one year ,in this study , detecting the bacterial suspension of Acidovorax avenae subsp.Citrulli and the bacterial quantity of Ha-mi seed extraction by NEST-PCR. The sensitivity are 2.6χ100cfu/ml and 2.6χ103cfu/ml respectively which improved 10000and 1000 times than the amplification by normal PCR . Detect the seeds of watermelon and Ha-mi melon from different places by NEST-PCR.The result shows that there is more Acidovorax avenae subsp.Citrulli on Ha-mi seed than water melon seed nowadays. The results shows the detective ratio is 73.3%, The seeds of Watermelon do not bring basically Acidovorax avenae subsp.Citrulli .The speed and sensitivity of NEST-PCR detect Acidovorax avenae subsp.citrulli are higher than normal PCR.It is a safe,effective,economical,feasible method to control baterial blotch by inducing muskmelon seedings with 90ug/ml BTH 4 days and 0.9% H2SiO4 2 or 4 days. After muskmelon seedling was induced by the BTH and H2SiO4 and inoculated Acidovorax avenae subsp.citrulli. its POD, PPO and PAL enzyme activity are obviously heightened and inducing effect of BTH is better than that H2SiO4. POD amount expression induced by BTH is higher than that of H2SiO4 in muskmelon seedings.In this study ,the resistance of 15Ha-mi melon ,2 edible seed melon and 15 watermelon were identified in greenhouse by Spraying Acidovorax avenae subsp. The results showed although of the degree of incidence all Ha-mi, seed melon and watermelon varieties are obvious difference, all of them were susceptible.And their disease index exceed 40.The resistance of watermelon and edible seed watermelon were higher than Ha-mi melon .We found that it was no obvious correlation between the resistance and chromosome types, growing period.