2个芒果品种果实对炭疽病的抗性差异及其相关生理基础

The Difference in Resistance of Two Mango Cultivars to Anthracnose Disease and Its Physiology Mechanism Involved

摘要:

2个芒果品种果实对炭疽病的抗性差异及其相关生理基础，为利用抗病性诱导技术防治芒果采后病害提供理论依据。方法：以两个芒果品种“吉禄(Zill)”和“凯特(Keitt)”为试材，通过人工接种和未接种芒果炭疽菌的方式，比较2个品种芒果采后抗病性的差异，并测定了两个芒果品种在果实发育和贮藏过程中苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)和多酚氧化酶(PPO)等防御酶的活性以及过氧化氢(H₂O₂)、总酚和木质素等次生抗菌物质含量的变化。结果：对接种炭疽菌的芒果果实，“凯特”芒果的病斑直径显著小于“吉禄”芒果，对未接种炭疽菌的芒果果实，“凯特”芒果的病情指数显著小于“吉禄”芒果，表明“凯特”芒果果实对炭疽病的抗性强于“吉禄”芒果；与“吉禄”芒果相比，在果实发育和贮藏过程中“凯特”芒果果实有较高的苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)和多酚氧化酶(PPO)等防御酶的活性以及过氧化氢(H₂O₂)、总酚和木质素等次生抗菌物质的含量。结论：“凯特”芒果对炭疽病的抗性强于“吉禄”芒果，并且这些防御酶和抗性物质可能在芒果果实对 炭疽菌侵染的抗性反应中起着重要的作用。

Objectives: The difference in resistance of two mango cultivars to anthracnose and the possible physiology mechanism involved were studied to provide theoretical references for controlling postharvest diseases of mango fruit by using the technology of induced disease resistance. Methods: The difference in the resistance between two mango cultivars (“Zill” and “Keitt”) to postharvest disease was examined by inoculation or non-inoculation with pathogen Colletotrichum gloeosporioides, and the defense enzyme activities of phenylalanine ammonia lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO) and the contents of hydrogen peroxide (H₂O₂), total phenolic compounds and lignin during fruit development and storage were determined. Results: The results showed that in fruits inoculated with C. gloeosporioides, the lesion size on “Keitt” fruit was smaller than that on “Zill”; in non-inoculated fruits, the disease index of “Keitt” was lower than that of “Zill”. This indicated “Keitt” was more disease resistant than “Zill”. Compared with “Zill”, “Keitt” showed higher enzymatic activities of PAL, POD, and PPO and the accumulation of more H₂O₂, total phenolic compounds and lignin content in fruits during fruit development and storage. Conclusions: These results suggest that “Keitt” is more disease resistant than “Zill” to anthracnose and the defense enzymes and antifungal substance probably play an important role in the resistance of mango fruits to anthracnose infection.