茉莉酸甲酯提高膜醭毕赤酵母对杨梅果实采后绿霉病生防效力的研究

研究了茉莉酸甲酯(Methyl jasmonate,MeJA)复合膜醭毕赤酵母(Pichia membranaefaciens)处理对"乌种"杨梅果实由桔青霉(Penicillium citrinum)引起的绿霉病的抑制效果,同时分析了MeJA对酵母菌和病原菌生长以及果实抗病性的影响。结果显示:MeJA可有效提升P.membranefacien生防效力,10μmol/L MeJA与1×109CFU/mL P.membranefacien菌悬液的复合处理比单一处理能更有效抑制杨梅果实绿霉病的发生;该复合处理也更为显著的诱导了杨梅果实抗病相关酶活性的上升;此外,MeJA还可直接提高P.membranaefaciens在NYDB培养基和杨梅果实伤口处的数量,但MeJA对病原菌P.citrinum生长无抑制效果。这些结果表明,MeJA主要是通过直接促进拮抗酵母生长以及间接诱导果实抗病性来提升P.membranaefaciens生防效力,从而起到有效抑制杨梅果实采后腐烂的作用。

Study on Imporved Biocontrol of Pichia membranifaciens for Control of Green Mold Decay on Chinese Bayberry Fruit by Methyl Jasmonate

The present study was to investigate the effect of the combined treatment of MeJA and antagonistic yeast Pichia membranifaciens for control of green mold decay caused by Penicillium citrinum on Chinese bayberry fruit(Myrica rubra Seib & Zucc.Cv Wumei) and to analyze the effect of MeJA on the growth of the yeast and pathogen as well as the disease resistance.The results exhibited that the biocontrol activity of P.membranifaciens on the disease was enhanced by the addition of MeJA,1×109 CFU/mL P.membranifaciens combined with 10 μmol/L MeJA resulted in a remarkably improved control of the disease compared with applying yeast or MeJA alone.Meanwhile,the combined treatment induced higher defense-related enzymes activities than either alone.In addition,adding MeJA positively influenced the population of P.membranifaciens in NYDB medium and fruit wounds.However,MeJA had no direct inhibitory effect on spore germination and germ tube elongation of P.citrinum.Thus,these results suggested that MeJA could improve the biocontrol activity of P.membranefaciens on green mold decay on Chinese bayberry fruit and the improved control of the disease by MeJA is directly because of the increased population size of antagonist,and indirectly because of the enhanced disease resistance.