关键词: 生物防治;甜瓜采后病害;遗传改良;2,4-二乙酰基间苯三酚;转座子

Abstract:

X4(Pseudomonas fluorescens biovar Ⅲ) is a biological strain screened from melon surface by direct biological determination method. The strains did not produce antibiotic 2,4-DAPG, but had good control ability for many melon post harvests diseases. In this paper, X4-G was constructed by integrating Tn5 transposon comprising 2,4-DAPG synthetic genetic cluster into X4 genome. It was confirmed being successfully inserted by PCR and TLC test, and could exist stably in X4-G strains. Both X4 and X4-G strains showed inhibition to post harvests diseases pathogens Fusarium SPP. and Trichothecium roseum in plate antagonism experiment. Strains X4 and X4-G had over 80% bio-control efficacy to T. roseum in melon, and X4-G was prior to X4. The results showed that the recombinant X4-G with 2,4-DAPG synthesis genes could improve the bio-control ability to melon post harvest diseases.

Key words: bio-control, melon post harvest disease, genetic improvement, 2,4-DAPG, transposon