芒果叶疫病胁迫下水杨酸对芒果幼苗生理作用的影响

Effects of Salicylic Acid on the Physiological Function of Mango Seedlings under the Stress of Leaf Blight

芒果属漆树科芒果属,性喜温暖,是世界五大热带水果之一,我国是世界芒果生产大国,近年来芒果种植面积逐步扩大,由于疏于管理,使得芒果病虫害种类和数量都在不断增多,给芒果生产造成了严重损失。叶疫病是芒果生产中常见的一种真菌病害,为研究叶疫病菌侵染芒果后相关抗性指标的变化及水杨酸对芒果叶疫病的抗性诱导机制,为芒果叶疫病菌的防治提供参考。试验将水杨酸溶液喷洒于台农1号芒果幼苗叶面,然后将已纯化的叶疫病菌,通过针刺法接种到健康种苗,将感染叶疫病病菌的种苗进行胁迫处理。设不接种+喷无菌水、接种叶疫病菌+喷无菌水、接种叶疫病菌+0.5 mmol/L水杨酸3组,分别在第1、3、5、7、9、11天采样测定生理指标。结果表明,只接种叶疫病菌后芒果幼苗的叶绿素、丙二醛、可溶性糖含量降低,脯氨酸含量增加,经0.5 mmol/L水杨酸处理后提高了叶绿素、丙二醛、可溶性糖含量,降低了脯氨酸含量。可见,外施水杨酸可以减缓叶疫病菌对芒果幼苗的伤害,提高芒果幼苗对叶疫病菌的抵抗力。

Mango belongs to the family Anacardiaceae and the genus Mango.It prefers warmth and is one of the five tropical fruits in the world.China is a major producer of mangoes in the world,and in recent years,the planting area of mangoes has gradually expanded.Due to poor management,the number and variety of mango diseases and pests have been increasing,causing serious losses to mango production.Leaf blight is a common fungal disease in mango fruit production.In order to study the changes in relevant resistance indexes after the infection by Alternaria tenuissima and the resistance induction mechanism of salicylic acid on mango leaf blight,and to provide a reference for the prevention and control of mango leaf blight in mango fruit production.In this study,salicylic acid solution was sprayed on the leaves of mango seedlings,and purified Alternaria tenuissima was inoculated into healthy seedlings through the wound.The seedlings infected with leaf blight pathogens were subjected to stress treatment.Three groups were set as follows:non inoculation+spraying sterile water,inoculation with Alternaria tenuissima+spraying sterile water,inoculation with Alternaria tenuissima+0.5 mmol/L salicylic acid,and samples were obtained to measure physiological indexes at 1,3,5,7,9,11 d post inoculation,respectively.The results showed that after inoculation with Alternaria tenuissima,the content of chlorophyll,malondialdehyde,and soluble sugar in mango seedlings decreased,while the proline content increased.After treatment with 0.5 mmol/L of salicylic acid,the content of chlorophyll,malondialdehyde,and soluble sugar increased,while the content of proline decreased.Therefore,external application of salicylic acid could reduce the damage of leaf blight on mango seedlings and improve the resistance of mango seedlings to leaf blight.