[Allelopathic effects of phenolic compounds of melon root exudates on Fusarium oxysporum f. sp. melonis].

In this study, the phenolic compounds of melon root exudates were identified by HPLC and seven phenolic compounds including gallic acid, phthalic acid, syringic acid, salicylic acid, ferulic acid, benzoic acid and cinnamic acid were observed. The laboratory experiment showed that ferulic acid, benzoic acid and cinnamic acid of 0.1 and 0.25 mmol x L(-1) could significantly promote the germination of Fusarium oxysporum f. sp. melonis spore while salicylic acid inhibited the spore germination to some degree. Syringic acid and ferulic acid significantly promoted the mycelium growth at the late stage of incubation. The pot experiments demonstrated that cinnamic acid, benzoic acid and ferulic acid enhanced melon infection at concentrations of 0.5, 0.1 and 0.5 mmol x L(-1).

[UP-PCR diversity analysis of Fusarium population isolated from greenhouse melon soils].

A total of 112 Fusarium isolates were obtained from 36 soil samples collected from the greenhouse melon fields of Liaoning Province, among which, 11 species were identified by traditional morphological classification and rDNA sequence analysis. Universally Primed PCR (UP-PCR) was conducted to analyze the 25 strains of test Fusarium isolates and 3 strains of positive control Fusarium isolates. The results indicated that a total of 73 bands appeared after amplification by using 6 primers, and 66 bands (90.4%) were polymorphic. The isolates were clustered into eight groups at the similarity of 0.736 by cluster analysis, among which, 14 isolates were clustered into one group. It was concluded that UP-PCR could present the genetic relationship and difference among Fusarium strains, being able to be used as an assistant method for Fusarium classification.