Background

Arbuscular mycorrhizal (AM) fungi form symbiotic associations with roots in most land plants. AM symbiosis provides benefits to host plants by improving nutrition and fitness. AM symbiosis has also been associated with increased resistance to pathogen infection in several plant species. In rice, the effects of AM symbiosis is less studied, probably because rice is mostly cultivated in wetland areas, and plants in such ecosystems have traditionally been considered as non-mycorrhizal. In this study, we investigated the effect of AM inoculation on performance of elite rice cultivars (Oryza sativa, japonica subspecies) under greenhouse and field conditions, focusing on growth, resistance to the rice blast fungus Magnaporthe oryzae and productivity.

Results

The response to inoculation with either Funneliformis mosseae or Rhizophagus irregularis was evaluated in a panel of 12 rice cultivars. Root colonization was confirmed in all rice varieties. Under controlled greenhouse conditions, R. irregularis showed higher levels of root colonization than F. mosseae. Compared to non-inoculated plants, the AM-inoculated plants had higher Pi content in leaves. Varietal differences were observed in the growth response of rice cultivars to inoculation with an AM fungus, which were also dependent on the identity of the fungus. Thus, positive, negligible, and negative responses to AM inoculation were observed among rice varieties. Inoculation with F. mosseae or R. irregularis also conferred protection to the rice blast fungus, but the level of mycorrhiza-induced blast resistance varied among host genotypes. Rice seedlings (Loto and Gines varieties) were pre-inoculated with R. irregularis, transplanted into flooded fields, and grown until maturity. A significant increase in grain yield was observed in mycorrhizal plants compared with non-mycorrhizal plants, which was related to an increase in the number of panicles.

Conclusion

Results here presented support that rice plants benefit from the AM symbiosis while illustrating the potential of using AM fungi to improve productivity and blast resistance in cultivated rice. Differences observed in the mycorrhizal responsiveness among the different rice cultivars in terms of growth promotion and blast resistance indicate that evaluation of benefits received by the AM symbiosis needs to be carefully evaluated on a case-by-case basis for efficient exploitation of AM fungi in rice cultivation.

中文翻译：

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丛枝菌根真菌的根系定植对水稻生长，生产力和抗稻瘟病的影响。

背景

丛枝菌根（AM）真菌与大多数陆地植物的根形成共生关系。AM共生通过改善营养和适应性为寄主植物提供好处。AM共生还与几种植物对病原体感染的抗性增强有关。在水稻中，对AM共生的影响研究较少，这可能是因为水稻主要在湿地种植，并且传统上将这种生态系统中的植物视为非菌根。在这项研究中，我们调查了AM接种对在温室和田间条件下优良水稻品种（水稻，粳稻亚种）的性能的影响，重点是水稻的生长，对稻瘟病菌稻瘟病的抗性和生产力。

结果

与任一给接种的响应Funneliformis霉ö řRhizophagus irregularis在12个水稻品种一个面板进行评价。在所有水稻品种中均确认了根定植。在受控的温室条件下，不规则红球菌显示出比mosseae更高的根定植水平。与未接种植物相比，接种AM的植物叶片中的Pi含量更高。在水稻品种对AM真菌接种的生长反应中观察到各种差异，这也取决于真菌的身份。因此，在水稻品种中观察到对AM接种的阳性，微不足道和阴性反应。接种F. mosseae或不规则红杆菌还对稻瘟病真菌具有保护作用，但菌根诱导的稻瘟病抗性水平因宿主基因型而异。水稻幼苗（Loto和Gines变种）已预先接种了不规则红球菌，移植到水淹田中，直到成熟。与非菌根植物相比，菌根植物的谷物产量显着增加，这与穗数的增加有关。

结论

此处的结果表明，水稻植物受益于AM共生，同时说明了使用AM真菌改善栽培水稻的生产力和抗稻瘟病的潜力。在水稻生长促进和抗稻瘟病性方面，不同水稻品种在菌根反应性方面的差异表明，为有效利用水稻中的AM真菌，需要逐案仔细评估对AM共生所获得的益处的评估。培养。