蜜橘酸腐病病原菌的分离鉴定以及不同抑菌剂处理对其控制效果

为确定蜜橘果实酸腐病的致病菌及膜醭毕赤酵母、水杨酸和壳寡糖对蜜橘果实采后酸腐病的控制效果,从自然发病的蜜橘果实上分离出一株致病真菌,通过形态学特征、rDNA-ITS分析以及致病性检测,发现该真菌为蜜橘白地霉(Geotrichum candidum)。离体实验发现2.5 mmol/L水杨酸、质量分数1.5%壳寡糖处理能够抑制白地霉孢子萌发和菌丝的生长,膜醭毕赤酵母产生的挥发性物质能够抑制白地霉菌丝的生长。果实上的实验结果表明,1×10~8 CFU/m L膜醭毕赤酵母、2.5 mmol/L水杨酸、1.5%壳寡糖同孔接种和异孔接种处理均能够有效抑制蜜橘果实酸腐病的发病率和病斑直径的上升,其中同孔处理膜醭毕赤酵母效果最好,异孔处理水杨酸效果最好。

Isolation and Identification of Sour Rot Pathogen of Satsuma Mandarin and Inhibitory Effects of Three Antifungal Substances on It

This investigation aimed to identify the sour rot pathogen of satsuma mandarin and to test the effect of Pichia membranaefaciens, salicylic acid and chitosan oligosaccharide in controlling this pathogen. We isolated a fungal pathogen from naturally infected citrus fruits and identified it as Geotrichum candidum on the basis of morphological characteristics, rDNA-ITS sequence analysis and pathogenicity. In addition, 2.5 mmol/L salicylic acid and 1.5% chitosan oligosaccharide could significantly inhibit the germination and mycelial growth of G. candidum under detached conditions. The volatile substances of P. membranaefaciens could inhibit the mycelial growth of G. candidum. Similarly, 1 × 108 CFU/mL P. membranaefaciens, 2.5 mmol/L salicylic acid and 1.5% chitosan oligosaccharide treatment of the same and different wounds could control sour rot incidence and lesion diameter, especially P. membranaefaciens and salicylic acid through inoculation on the same wounds and different wounds, respectively.