BACKGROUND Dirty panicle disease (DPD) caused by several fungal phytopathogens results in damage and depreciation of rice seeds. Unhealthy rice seeds with DPD are potent reservoirs of pathogens and unable to be used as seed stock as they can spread the disease in the paddy fields leading to the severe loss of rice yield and quality. In this study, we aim to search for beneficial endophytes of commercially cultivated rice plants and utilize them as biostimulants in seed biopriming for fertility recovery and disease suppression of unhealthy rice seeds. RESULTS Forty-three bacterial endophytes were isolated from rice plants grown in the herbicide-treated paddy fields. Five isolates of these endophytes belonging to the genus Bacillus show excellent antifungal activity against fungal pathogens of DPD. Based on germination tests, biopriming unhealthy rice seeds by soaking in bacterial suspensions for 9 or 12 h was optimal as evidenced by the lowest disease incidence and longer shoot and root lengths of seedlings germinated, compared with controls made of non-treated or hydroprimed healthy and unhealthy seeds. Pot experiments were carried out to evaluate the impact of seed biopriming, in which the percentage of healthy rice yield produced by rice plants emerging from bioprimed seeds was not significantly different, compared to the controls originating respectively from non-treated healthy seeds and chemical fungicide-treated unhealthy seeds. CONCLUSION Biopriming of unhealthy rice seeds with herbicide-tolerant endophytic bacteria could recover seed fertility and protect the full life cycle of emerging rice plants from fungal pests. With our findings, seed biopriming is a straightforward approach that farmers can apply to recover unhealthy rice seed stock, which enables them to reduce the cost and use of agrochemicals in the commercial production of rice and to promote green technology in sustainable agriculture.

中文翻译：

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水稻植物的耐除草剂内生细菌，作为不健康水稻种子的繁殖力恢复和疾病抑制的生物引发剂。

背景技术由几种真菌性植物病原体引起的肮脏的穗病（DPD）导致水稻种子的损坏和贬值。具有DPD的不健康水稻种子是有效的病原体库，不能用作种子库，因为它们可以在稻田中传播疾病，导致水稻产量和质量严重下降。在这项研究中，我们旨在寻找商业种植的水稻植物的有益内生菌，并将其用作种子生物引发中的生物兴奋剂，以恢复不健康水稻种子的繁殖力和抑制疾病。结果从在除草剂处理过的稻田中生长的水稻植株中分离出43种细菌内生菌。这些属于芽孢杆菌属的内生菌的五种分离物对DPD的真菌病原体显示出优异的抗真菌活性。根据发芽测试，与未处理或加水处理的健康和不健康种子制成的对照相比，通过在细菌悬浮液中浸泡9或12 h来生物引发不健康的水稻种子是最佳的，这证明了最低的发病率以及发芽的幼苗的苗长和根长更长。进行盆栽实验以评估种子生物引发的影响，与分别来自未经处理的健康种子和化学杀真菌剂的对照相比，由生物引发种子萌发的水稻植物产生的健康水稻产量百分比没有显着差异。处理不健康的种子。结论用耐除草剂的内生细菌对不健康水稻种子进行生物引发可以恢复种子的繁殖力，并保护新兴水稻植物免受真菌害虫的整个生命周期。根据我们的发现，