Plant growth promoting rhizobacteria improve growth and yield related attributes of chili under low nitrogen availability

Abstract

Nitrogen (N) is a macronutrient desired by crop plants in large quantities. However, hiking fertilizer prices need alternative N sources for reducing its requirements through appropriate management practices. Plant growth promoting rhizobacteria (PGPR) are well-known for their role in lowering N requirements of crop plants. This study assessed the impact of PGPR inoculation on growth, allometry and biochemical traits of chili under different N doses. Two PGPR, i.e., Azospirillum ‘Er-20’ (nitrogen fixing) and Agrobacterium ‘Ca-18’ (phosphorous solubilizing) were used for inoculation, while control treatment had no PGPR inoculation. Six N doses, i.e., 100, 80, 75, 70, 60 and 50% of the N required by chili were included in the study. Data relating to growth traits, biochemical attributes and yield related traits were recorded. Interaction among N doses and PGPR inoculation significantly altered all growth traits, biochemical attributes and yield related traits. The highest values of the recorded traits were observed for 100% N with and without PGPR inoculation and 75% N with PGPR inoculation. The lowest values of the recorded traits were noted for 50% N without PGPR inoculation. The PGPR inoculation improved the measured traits compared to the traits recorded noted in same N dose without PGPR inoculation. Results revealed that PGPR had the potential to lower 25% N requirement for chili. Therefore, it is recommended that PGPR must be used in chili cultivation to lower N requirements.

Plant Growth-Promoting Rhizobacteria Improve Growth and Fruit Quality of Cucumber under Greenhouse Conditions

“…In similar studies [26], using Bacillus velezensis as inoculant of C. sativus, it was observed that the host plant modifies the root structure, which improves water and nutrient uptake, promoting a higher photosynthetic rate. It has been suggested that the modification of the root structure of a cucumber plant is related to the phytohormone indoleacetic acid (IAA) produced by S. meliloti, A. radioresistens, and P. paralactis [11,14,27]. In addition, it has been reported that S. meliloti and A. radioresistens possess the ability to fix nitrogen and solubilize phosphate, resulting in an increase on the number of late-stage roots and root hairs, since these elements are essential for the plant to increase photosynthetic pigments and proteins, which improves photosynthetic activity and rate, having a positive effect on plant development and a greater accumulation of biomass [28,29].Furthermore, it has been pointed out that IAA is associated with cell division and differentiation, which improves the structure of the root system [30][31][32].…”

“…Plant growth-promoting rhizobacteria (PGPR) are a microorganism group able to increase the shoot and root length, improve water and nutrient absorption, and improve fruit quality and productivity in plants [13]. Undoubtedly, among the promoting mechanisms the production of phytohormone (auxin and cytokinins), volatile compounds, siderophores, atmospheric nitrogen fixation processes, and solubilized phosphate are the most important [12,14].…”

“…Moreover, the common genera of PGPR reported are Azospirillum, Pseudomonas, Bacillus, Azotobacter, Caulobacter, Flavobacterium, Enterobacter, among others [14][15][16]. One of the most studied genera within PGPR is the Pseudomonas [17].…”

A Potential Biofertilizer—Siderophilic Bacteria Isolated From the Rhizosphere of Paris polyphylla var. yunnanensis

“…Microorganisms (bacteria and fungi) present in the rhizosphere soil of plants play a significant role in the whole plant growth process ( Bukhat et al, 2020 ). Among these, plant growth-promoting rhizobacteria (PGPR) can promote the plant growth by various direct or indirect mechanisms, such as nitrogen fixation ( Raza et al, 2021 ), phosphate solubilization ( Sahu et al, 2022 ), siderophore production ( Braud et al, 2009 ; Ghazy and El-Nahrawy, 2021 ), heavy metal resistance ( Ma et al, 2016 ; Bennis et al, 2022 ), indole compound production ( Zahir et al, 2010 ), biocontrol ( Hosseini et al, 2021 ), and stress responses, including 1-aminocyclopropane-1-carboxylate (ACC) deaminase production ( Gupta et al, 2021 ), drought tolerance ( Mansour et al, 2021 ), and halotolerance ( Wang et al, 2022 ). In the past few decades, many studies on the screening and identification of these bacteria have been reported.…”

Soil Microbes Drive the Flourishing Growth of Plants From Leucocalocybe mongolica Fairy Ring

“…Stenotrophomonas malthopilia KJKB5.4, Stenotrophomonas pavanii LMTSA5.4, Bacillus cereus AJ34 and Alcaligenes faecalis AJ14 have rhizobacterial antibiosis to against Curvularia lunata by producing antibiotic compounds and increasing plant growth ( Rahma et al, 2021 ). The inoculation of Azospirillum Er-20 and Agrobacterium Ca-18 significantly improved the growth and yield of pepper, and had the potential to lower 25% N requirement for chili by nitrogen fixing and phosphorous solubilizing ( Raza et al, 2021 ). Xu et al (2022) found that the PGPR ( Tsukamurella tyrosinosolvens P9 and Burkholderia pyrrocinia P10) inoculations enhanced the photosynthetic performance, activated the antioxidant defense system, and decreased the ROS level of peanut plants, which alleviated the salt-induced cell damage and enhanced the salt tolerance and growth of peanut.…”