水稻稻曲病菌侵染行为的研究现状及展望

Progress and Perspect of Infection Behavior of Ustilaginoidea virens

稻曲病为我国水稻生产上严重影响稻米品质与产量的重要病害,研究稻曲病菌侵染行为可为稻曲病抗性品种选育、防控药剂特异性靶标选择以及防控策略制定等提供理论参考。从稻曲病接种体系、初侵染源、侵染关键期、侵染位点、侵染过程、侵染机制等方面进行系统阐述。当前研究表明,稻曲病菌通过菌核或厚垣孢子越冬后形成分生孢子作为初侵染源,在水稻幼穗形成后通过人工注射将稻曲病菌分生孢子液注入水稻穗苞,病菌通过颖壳间隙进入颖内后,首先攻击水稻花丝,阻止水稻花粉成熟,阻断子房受精,劫持水稻营养库进而形成稻曲球。稻曲病菌与水稻花丝的分子识别机制、稻曲病菌如何激发水稻相关灌浆基因的表达进而获取营养物质形成稻曲球可能是将来的研究方向。

Rice false smut is an important disease seriously affecting the quality and yield of rice in China.The study on the infection behavior of Ustilaginoidea virens may provide theoretical references for breeding resistant varieties,selecting specific targets for new fungicides and designing control strategies.The topics were reviewed in this paper,which included the inoculation system,the primary infection source,the critical infection period,the infection site,the infection process and the infection mechanism of U.virens.Current studies have shown that the conidia of U.virens form after overwintering by sclerotia or chlamydospore as the primary source of infection.The mycelium spore suspension of U.virens is injected into the spikelets bud by artificial injection after the formation of young panicles of rice.The pathogen enters the rice glume from the gap between the palea and lemma,attacks the rice filaments first,and prevents the pollen from maturing.The ovary fertilization is broken and the rice nutrient bank is hijacked to form rice false smut balls.Molecular recognition mechanism between U.virens and rice filaments,and how U.virens can stimulate the expression of rice-related filling genes and obtain nutrients to form rice false smut balls may be the future research directions.