Low and erratic rainfall can cause a significant reduction in crop yields in agriculture systems that rely exclusively on rain water. Some plant growth promoting rhizobacteria (PGPR) capable of producing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase can mitigate the negative impact of water stress on plant in rainfed agriculture through modulation of plant stress hormone ethylene. The present study was conducted in rainfed areas to demonstrate the potential of PGPR with ACC-deaminase activity to enhance the growth and yield of wheat (Triticum aestivum L.) under field conditions. Previously isolated bacterial strains (Serratia odorifera CC7, Aerococcus viridans CK3 and Serratia proteamaculans R20) having in-vitro ACC deaminase activity were used for inoculation. Peat, compost and biochar were used as carrier material for the formulation of biofertilizer. Our results show that application of the compost biofertilizer increased plant biomass up to 27% and grain yield up to 33.3% compared with uninoculated control. Maximum N and P content in grain was observed 24.7 % and 25.8% respectively. Maximum ACC-deaminase activity of 821 nmol g⁻¹ biomass h⁻¹ was observed with strain CC7, while root colonization activity was also highest in case of strain CC7 i.e 6.2 $\times$ 10⁶ compared to other strains. All the strains showed positive response to phosphate solubilization activity as well. Furthermore, ACC deaminase gene isolated from CC7 strain showed 79.1% homology to the ACC deaminase gene of Achromobacter, 83.9% homology to the ACC deaminase gene of Pseudomonas. These findings indicate that PGPR isolated from rainfed area can be used for biofertilizer formulation which could be very effective to increase the production of wheat in rainfed agriculture system.

在完全依赖雨水的农业系统中，低而不稳定的降雨会导致作物产量显着下降。一些能够产生1-氨基环丙烷-1-羧酸（ACC）脱氨酶的植物促生长根际细菌（PGPR）可以通过调节植物胁迫激素乙烯来减轻雨养农业中水分胁迫对植物的负面影响。本研究在雨养地区进行，以证明具有 ACC 脱氨酶活性的 PGPR在田间条件下提高小麦 ( Triticum aestivum L.)的生长和产量的潜力。先前分离的细菌菌株（Serratia odorifera CC7、Aerococcus viridans CK3 和Serratia proteamaculansR20) 具有体外 ACC 脱氨酶活性用于接种。泥炭、堆肥和生物炭被用作配制生物肥料的载体材料。我们的结果表明，与未接种的对照相比，堆肥生物肥料的应用使植物生物量增加了 27%，谷物产量增加了 33.3%。观察到谷物中最大的 N 和 P 含量分别为 24.7% 和 25.8%。用菌株CC7观察到821 nmol g ^-1生物量h ^{-1 的}最大ACC-脱氨酶活性，而在菌株CC7的情况下根定植活性也最高，即6.2$\times$10 ⁶与其他菌株相比。所有菌株也显示出对磷酸盐溶解活性的阳性反应。此外，从CC7菌株中分离的ACC脱氨酶基因与无色杆菌的ACC脱氨酶基因具有79.1%的同源性，与假单胞菌的ACC脱氨酶基因的同源性为83.9% 。这些发现表明，从雨养区分离的 PGPR 可用于生物肥料配方，这对于增加雨养农业系统中的小麦产量非常有效。