不同处理对桃形李采后病原菌的防治效果

桃形李采后极易发生病害,难以保鲜,为了控制桃形李采后病害的发生,通过对分离到的病原菌扩展青霉菌株(Penicillium expansum,TXL-01)进行形态学观察和对其它水果致病性试验,分别用硝普钠、葡萄籽提取物和NaHCO_3在PDA培养基上进行抑菌实验。结果表明:形态学观察发现致病菌菌丝有分枝和横隔膜,具帚形孢子囊,能产生大小不同的2种类型孢子;对多种水果侵染后均能致病,说明致病菌对宿主要求专一性不高;硝普钠和葡萄籽提取物只能在前3 d抑制病原菌的生长,但是在第4天以后与对照无明显差异;NaHCO_3浓度为0.10%和0.15%时,培养到第6天时能显著抑制病原菌生长;当NaHCO_3为0.2%时,培养到第12天时内还能抑制病原菌生长;再分别以0.10%、0.15%、0.20%NaHCO_3和0.20%NaHCO_3+1.0%壳聚糖(Chitosan)复合处理桃形李采后果实,发现0.20%NaHCO_3处理虽然也能减少果实腐烂率,但结合1.0%Chitosan涂膜处理对果实保鲜效果更好,可以显著抑制致病菌的发生,降低果实发病率,说明NaHCO_3和Chitosan复合处理可以应用于桃形李的采后保鲜。

Effects of Different Treatments on Pathogen Control Efficiency in Harvested Nane Fruit

Shengzhou Nane can easily accelerate the process of water loss,softening,microbial attacking and decay of fruits during post-harvest storage.The shelf life of fresh fruit is very short,and the fruit can deteriorate within a few days under ambient temperature.In order to control the fruit disease in harvested period,studies were conducted on the morphology of the isolated pathogen from fruit and its host range to other fruits.Three substances including nitroprusside,grape seed extract,and sodium bicarbonate were used on antibacterial tests.In addition,sodium bicarbonate in combination with 1.0％ chitosan was used as the preservation treatment in Shengzhou Nane.Morphological observation showed that the pathogen had diaphragm and broom-shaped sporangia branches and could produce two kinds of spore in different sizes.A variety of infected fruits revealed that the requirement for the pathogen's host range specificity was not so high.Nitroprusside and grape seed extract could inhibit the growth of the pathogen for the former 3 days,while there was no significant difference between the treatment and control after 4 days.Sodium bicarbonate with concentration of 0.10％,0.15％ could remarkably inhibit the growth of the pathogen for 6 days cultivation,and the inhibition lasted 12 days and with concentration of 0.20％,In addition,0.20％ sodium bicarbonate combined with 1.0％ Chitosan was used for postharvest plum could remarkably reduce the decay rate of fruits,indicating a better effect.Thus,the combinational treatment could significantly inhibit the occurrence of the pathogen and reduce morbidity in the fruit.As a result,an improvement in storability and thus prolonged storage time were achieved for Shenzhou Nane fruits during post-harvest period.