PDF(Pubmed)
Abstract：
Peatlands are marginal agricultural lands due to highly acidic soil conditions and poor drainage systems. Drought stress is a big problem in peatlands as it can affect plants through poor root development, so technological innovations are needed to increase the productivity and sustainability of upland rice on peatlands. Rhizobacteria can overcome the effects of drought stress by altering root morphology, regulating stress-responsive genes, and producing exopolysaccharides and indole acetic acid (IAA). This study aimed to determine the ability of rhizobacteria in upland rice to produce exopolysaccharides and IAA, identify potential isolates using molecular markers, and prove the effect of rhizobacteria on viability and vigor index in upland rice. Rhizobacterial isolates were grown on yeast extract mannitol broth (YEMB) medium for exopolysaccharides production testing and Nutrient Broth (NB)+L-tryptophan medium for IAA production testing. The selected isolates identify using sequence 16S rRNA. The variables observed in testing the effect of rhizobacteria were germination ability, vigour index, and growth uniformity. EPS-1 isolate is the best production of exopolysaccharides (41.6 mg/ml) and IAA (60.83 ppm). The isolate EPS-1 was identified as Klebsiella variicola using 16S rRNA sequencing and phylogenetic analysis. The isolate EPS-1 can increase the viability and vigor of upland rice seeds. K. variicola is more adaptive and has several functional properties that can be developed as a potential bioagent or biofertilizer to improve soil nutrition, moisture and enhance plant growth. The use of rhizobacteria can reduce dependence on the use of synthetic materials with sustainable agriculture.
摘要：
由于高酸性土壤条件和不良的排水系统，泥炭地是边缘农业用地。干旱胁迫是泥炭地的一个大问题，因为它可以通过不良的根系发育影响植物，因此，需要技术创新来提高泥炭地上旱稻的生产力和可持续性。根瘤菌可以通过改变根系形态来克服干旱胁迫的影响,调节应激反应基因，并产生胞外多糖和吲哚乙酸(IAA)。本研究旨在确定旱稻根际细菌产生胞外多糖和IAA的能力，使用分子标记鉴定潜在的分离株，并证明了根瘤菌对旱稻活力和活力指数的影响。根瘤菌分离物在酵母提取物甘露醇肉汤（YEMB）培养基上生长，用于胞外多糖生产测试，在营养肉汤（NB）L-色氨酸培养基上生长，用于IAA生产测试。所选择的分离株使用序列16SrRNA进行鉴定。在测试根瘤菌作用时观察到的变量是发芽能力，活力指数，和生长均匀性。EPS-1分离物是胞外多糖(41.6mg/ml)和IAA(60.83ppm)的最佳产量。使用16SrRNA测序和系统发育分析将分离的EPS-1鉴定为克雷伯氏菌。分离的EPS-1可以提高旱稻种子的活力和活力。K.variicola更具适应性，具有多种功能特性，可作为潜在的生物制剂或生物肥料来改善土壤营养，水分和促进植物生长。根瘤菌的使用可以减少对可持续农业使用合成材料的依赖。
