Abstract:

A strain of endophytic fungi A1 was isolated from the roots of Malus hupehensis Rehd. seedlings by using dilution separation methods after surface disinfection and grinding，and was identified as Penicillium oxalicum by observation of morphology，cultural characteristics compared the ITS rDNA sequences and β-tubulin sequences with the known standard strains sequences that of GenBank，and the MEGA5.05 software was used to construct the phylogenetic tree of the A1 strain. The similarity of the ITS rDNA and β-tubulin sequences between A1 strain and Penicillium oxalicum（KF152942.1，KC344990.1）were 100%，so it was finally identified as the nearest genetic relationship with Penicillium oxalicum. By using a potato medium and a corn meal medium，endophytic fungi A1 was respectively confrontation test with Fusarium oxysporum，F. moniliforme，F. proliferatum and F. solani. It could inhibit growth of hypha of F. oxysporum，F. moniliforme，F. proliferatum and F. solani to a variable extent，and increased by 42.0%，74.0%，47.0% and 54.5% on the potato medium，and the coefficient of antagonism could be reached Ⅱ or Ⅰ. Similarly，growth of hypha was increased by 60.5%，82.2%，68.4% and 53.4% and the coefficient of antagonism could be reached Ⅱ or Ⅰon the corn meal medium. That Penicillium oxalicum A1 had better inhibitory effect on four kinds of Fusarium sp. of the apple replant disease. Pot experimental results showed that fresh weight and dry weight were obviously increased by function of A1 manure，and were 2.53 and 2.35 times respectively higher than the control，so A1 manure could reduce the apple replant disease to a certain extent. At the same time soil F. oxysporum gene copy number was detected by using real-time fluorescence quantitative technique and found that Penicillium oxalicum A1 could inhibit the growth of F. oxysporum，and could be ulteriorly studied as a antagonism strain to control the apple replant disease.

Key words: apple, Penicillium oxalicum A1, Fusarium oxysporum, Fusarium moniliforme, Fusarium proliferatum, Fusarium solani, antagonism