Abstract
Present investigation was made to isolate and characterize plant growth promoting rhizobacteria (Rkh1 - Rkh4) from rhizosphere of four weeds: Chrysopogon aucheri,Lactuca dissecta, Solanum surratense and Sonchus arvensis thriving under high salinity (EC: 2.3 dS/m) of Khewra salt range and the results were compared with strain Rak isolated from rhizosphere (EC: 0.2 dS/m) of Solanum surratense grown in arid area of district Attock. The tolerance of all the strains was checked against the salt present in culture media in the form of rhizospheric soil filtrate of weeds collected from Khewra salt range. The nutrient contents of rhizospheric soil of weeds were measured. All the strains were capable to produce phytohormones indole-3-acetic acid (IAA), gibberellic acid (GA3), trans-zeatin riboside (t-zr) and abscisic acid (ABA) in the culture media. Inoculation of strains on soybean seedlings treated with or without 20 dS/m NaCl resulted in better growth and higher proline contents than control plants. The strains isolated from weeds of Khewra salt range particularly Rkh3 appears more promising for potential biofertilizers in saline fields. Key words: Plant growth promoting rhizobacteria, nutrient contents, salt tolerance, phytohormones production, proline contents.
Highlights
Soil salinity is an important limiting factor in agriculture economy
Present investigation was made to isolate and characterize plant growth promoting rhizobacteria (Rkh1 - Rkh4) from rhizosphere of four weeds: Chrysopogon aucheri, Lactuca dissecta, Solanum surratense and Sonchus arvensis thriving under high salinity (EC: 2.3 dS/m) of Khewra salt range and the results were compared with strain Rak isolated from rhizosphere (EC: 0.2 dS/m) of Solanum surratense grown in arid area of district Attock
Four PGPR strains were isolated from rhizospheric soil of weeds growing in Khewra salt range and they were named as: Rkh1 from rhizosphere of Chrysopogon aucheri, Rkh2 from rhizosphere of Lactuca dissecta, Rkh3 from rhizosphere of Solanum surattense and Rkh4 from rhizosphere of Sonchus arvensis
Summary
In addition to traditional breeding and genetic modification of plants (Van der straeten et al, 1990; Blumwald, 2000), recent focus of research involves implication of plant growth promoting rhizobacteria to combat salt stress. The plant growth promoting rhizobacteria increase water use efficiency, fresh and dry weight of plants (Mayak et al, 2004) and render the plants more tolerant to salt stress by improving antioxidant status and physiological response (e.g proline used as osmoregulant) of plants (Han and Lee, 2005). PGPR produce several other growth promoting substances including IAA, GA3, zeatin and ABA (Perrig et al, 2007). IAA producing PGPR have been isolated from Kallar grass (Leptochloa fusca (L.) Kunth) grown in salt effected soil of Pakistan and their growth promoting effects have been documented on rice (Mirza et al, 2006). The salt tolerant plants/halophytes usually have higher concentration of total salt and salt ions: Cl-, Mg, Na, K and HCO3- in their rhizosphere (Liangpeng et al, 2007)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
