Department of Plant Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
Department of Biosciences, University of Wah, Wah Cantt., Pakistan.
Arch Microbiol. 2019 Aug;201(6):769-785. doi: 10.1007/s00203-019-01644-w. Epub 2019 Mar 6.
The present study was aimed to investigate the effects of plant growth promoting rhizobacteria (PGPR) and plant growth regulators (PGRs) on the physiology and yield of wheat grown in less fertile sandy soil. The isolated PGPR strains were identified by 16S-rRNA gene sequencing as Planomicrobium chinense (P1), Bacillus cereus (P2) and Pseudomonas fluorescens (P3). Wheat varieties (Galaxy-13 and Pak-2013) differing in sensitivity to drought were soaked in fresh cultures of bacterial isolates and the PGRs (salicylic acid and putrescine) were sprayed at 150 mg/L on seedlings at three leaf stage. PGPR and PGRs treated plants showed significant increase in the contents of chlorophyll, sugar and protein even under harsh environmental conditions. Drought stress enhanced the production of proline, antioxidant enzymes and lipid peroxidation but a decrease was noted in the biochemical content (i.e. chlorophyll, protein and sugar) of inoculated plants. PGPR inoculation also significantly enhanced the yield parameters (i.e. plant height, spike length, grain yield and weight) and improved the fertility status of sandy soil. The accumulation of macronutrient, total NO-N and P concentration and soil moisture content of rhizosphere soil was also enhanced by PGPRs inoculation. It is concluded that the combined effects of PGPR and PGRs have profound effects on the biochemical responses and drought tolerance of wheat grown in sandy soils.
本研究旨在探讨植物促生根际细菌（PGPR）和植物生长调节剂（PGRs）对在贫瘠沙质土壤中生长的小麦的生理和产量的影响。通过 16S-rRNA 基因测序鉴定分离的 PGPR 菌株为中华根瘤菌（P1）、蜡状芽孢杆菌（P2）和荧光假单胞菌（P3）。选用对干旱敏感程度不同的小麦品种（Galaxy-13 和 Pak-2013），将其在新鲜细菌分离株培养液中浸泡，并在三叶期将 PGRs（水杨酸和腐胺）以 150mg/L 的浓度喷洒在幼苗上。PGPR 和 PGRs 处理的植物即使在恶劣的环境条件下，其叶绿素、糖和蛋白质含量也显著增加。干旱胁迫会增强脯氨酸、抗氧化酶和脂质过氧化的产生，但接种植物的生化含量（即叶绿素、蛋白质和糖）会下降。PGPR 接种还显著提高了产量参数（即株高、穗长、籽粒产量和重量），并改善了沙质土壤的肥力状况。接种 PGPR 还可增强根际土壤中大量营养元素、总硝态氮和磷浓度以及土壤含水量的积累。综上所述，PGPR 和 PGRs 的联合作用对沙质土壤中生长的小麦的生化反应和耐旱性有深远影响。
