姬松茸粗多糖防治烟草花叶病毒病

Control of Tobacco Mosaic Virus Disease with Crude Polysaccharides of Agaricus blazei

烟草花叶病毒(Tobacco mosaic virus,TMV)是导致茄科(Solanaceae)作物减产的重大因素,为探寻防治烟草花叶病的食用菌源多糖材料,采用半叶法、五点注射试验和系统寄主侵染活性评价测定6种粗多糖对TMV的防治效果。结果表明:姬松茸(Agaricus blazei)粗多糖提取率最高,可达24.32%,其次是平菇(Pleurotus ostreatus)为18.56%,最低为杏鲍菇(Pleurotus eryngii)10.04%。总糖含量中,姬松茸总糖明显高于其他种类,达到37.71%,其次是桑黄(Phellinus igniarius)和灵芝(Ganoderma lucidum),总糖含量均超过32.00%,此外姬松茸粗多糖的硫酸基含量高达2.10%。半叶法测定6种粗多糖对TMV的防治效果,结果显示,多糖喷施48 h后对接种病毒能达到较好的预防效果,其中云芝粗多糖、姬松茸粗多糖、平菇粗多糖的预防效果均达到60.00%以上。尤其是24 mg/mL姬松茸粗多糖的预防效果达92.04%,叶片的枯斑数目明显少于清水对照组。在五点注射试验中,姬松茸粗多糖处理的荧光斑点亮度弱于对照组,同时新叶上未出现荧光点,抑制率达38.18%,在病毒侵入前期姬松茸粗多糖有抑制作用,能够延缓TMV的移动速度,减慢系统侵入进程。在系统寄主NC-89上,姬松茸粗多糖对TMV的防治效果高达76.81%,效果优于0.5%香菇多糖水剂和1.8%辛菌胺醋酸盐水剂处理组,当姬松茸粗多糖浓度为48 mg/mL时植株出现损伤,多糖浓度过高在植株表面形成沉淀,引起植株黄化。大田试验显示,姬松茸粗多糖对TMV的治疗效果为70.31%,对叶片扭曲、蜷缩、停止生长的植株有明显改善。同时对TMV有一定的抑制作用,喷施姬松茸粗多糖的烟草发病时间延后,烟草长势良好,叶片伸展。本研究结果为进一步研究真菌多糖防治烟草花叶病毒的作用方式和机制奠定基础,对绿色防控作物TMV有一定的理论意义和实际意义。

Tobacco mosaic virus(TMV)is a major factor leading to the yield reduction of Solanaceae crops.In order to explore edible fungus-derived polysaccharide materials for the prevention and control of Tobacco mosaic virus,the control effect of six crude polysaccharides against TMV was determined by the half-leaf method,five-point injection test and systematic host infection activity evaluation.Among them,the extraction rate of crude polysaccharide from Agaricus blazei,24.32%,was the highest,followed by Pleurotus ostreatus 18.56%,and that from Pleurotus eryngii,10.04%was the lowest.The total sugar content of A.blazei was significantly higher than that of other species,reaching 37.71%,followed by that of P.igniarius and G.Lucidum,exceeding 32.00%.In addition,the sulfate content of A.blazei crude polysaccharide was also as high as 2.10%.In this research,the inhibitory effect of the crude polysaccharides was determined by the half leaf method.Among the 6 tested polysaccharide treatments,the polysaccharides that were in-oculated after treated for 48 h had a good inhibition on TMV.The preventive effects of P.ostreatus,C.versicolor and A.blazei reached more than 60.00%.Especially,the preventive effect of 24 mg/mL A.blazei crude polysaccharide was up to 92.04%,and the number of dead spots on the leaves was significantly less than those in the clear water control group.In the five-point injection test,the inhibition rate of A.blazei crude polysaccharide was 38.18%.The brightness of the fluorescent spots was weaker than that in the control group,the fluorescent area did not change much,and did not ap-peared in the new leaves.A.blazei crude polysaccharide had an inhibitory effect in the early stage of virus infection,which could delay the moving speed of TMV and slow down the system invasion process.On NC-89,the control effect of agaricus antler polysaccharide on TMV was as high as 76.81%,which was better than that of 0.5%lentinan water agent and 1.8%octinamine acetate water agent.When the concentration was 48 mg/mL,the plants were damaged,and the excessive concentration of polysaccharide formed precipitation on the surface of the plants,causing the plants to yellow.Field test showed that the treatment effect of A.blazei crude polysaccharides on TMV was 70.31%.The plants with twisted,curled leaves and stopped growing had an obvious improvement.At the same time,it had a certain inhibi-tory effect on TMV,the onset time of sprayed tobacco was delayed,the tobacco grew well,and the leaves were extended.The results of this study would lay a foundation for further study on the action mode and mechanism of fungal polysac-charides against Tobacco mosaic virus.