Effectiveness of Rhizosphere Bacteria for Control of Root Rot Disease and Improving Plant Growth of Wheat (<i>Triticum </i><i>a</i><i>estivum</i> L)

Abstract

Pathogenic fungus Rhizoctonia solani causes root rot disease in wheat leading to collapsing of the aerial part of the plant. To characterize antagonistic bacteria, one hundred and thirty bacterial isolates were obtained from the rhizosphere soil of wheat and these rhizobacterial isolates alongwith 72 reference strains were screened for their antagonistic interactions against R. solani under cultural conditions. Sixteen bacterial isolates inhibited the growth of R. solani and growth inhibition zone varied from 6-15 mm by different rhizobacterial isolates. Two isolates WPS3 and WPS90 caused maximum growth inhibition of the fungi. Growth inhibiton of the pathogenic fungi was also observed using culture filterates of antagonistic rhizobacterial isolates. The protein estimation of the culture filterates showed that the amount of protein excreted by different rhizobacterial isolates varied from 3.6 to 33.0 mg ml -1 of the supernatant. The loss of antagonistic activity after treatment with proteinase K and high temperature treatment indicated that excreted proteins are responsible for the antagonism. Pot house studies showed that inoculation of R. solani in wheat caused 85-90% root rot disease incidence at 60 to 90 days of plant growth. The single inoculation of rhizobacterial isolate WPS3 resulted in 131% increase of plant dry weight as compared to uninoculated control plants. The coinoculation of isolate WPS3 with R. solani enhanced 115% plant dry weight whereas coinoculation of Pseudomonas isolate WPS90 caused 98% increase in plant dry weight in comparison to control uninoculated plants at 90 days of plant growth. Coinoculation of Pseudomonas isolates WPS3 and WPS90 with R. solani also caused 88.9 and 66.7% disease control, respectively at 90 days of plant growth. Thus, Pseudomonas isolate WPS3 could be further exploited for plant growth improvement under field conditions.

Growth stimulation of clusterbean (Cyamopsis tetragonoloba) by coinoculation with rhizosphere bacteria and Rhizobium

“…These interactions could be beneficial, neutral or with detrimental effects (Walia et al, 2014). Some microbial populations in the rhizosphere termed as plant growthgrowth promoting rhizobacteria (PGPR) benefit the plant in a variety of ways, including: (i) increased recycling, solubilization and uptake of mineral nutrients such as nitrogen, phosphorus and potassium (Basak and Biswas, 2008;Sindhu et al, 2009;Parmar and Sindhu, 2013), (ii) synthesis of auxins, vitamins, amino acids and gibberlins (Lugtenberg and Kamilova, 2009;Jangu and Sindhu, 2011) and (iii) antagonism with potential plant pathogens by production of antibiotics, siderophores, hydrocyanic acid and/or hydrolytic enzymes (Weller, 2007;Dua and Sindhu, 2012). These different soil microorganisms possessing beneficial characteristics are used as bioinoculants to improve productivity of various crops in sustainable agriculture (Welbaum et al, 2004;Compant et al, 2010).…”

Field assessment of microbial inoculants to control Rhizoctonia root rot on wheat

“…Microbes have also been isolated and shown to be able to reduce Rhizoctonia disease on wheat (Barnett et al, 2006;Barnett et al, 2017;Broadbent et al, 1971;Dua and Sindhu, 2012;Mavrodi et al, 2012;Yin et al, 2013), and the potential for using biocontrol inoculants has been well documented (Berg, 2009;Dutta and Podile, 2010) with increasing social and economic drivers for the use of these agents (Bailey et al, 2010).…”

Enumeration and Identification of Rhizospheric Microorganisms of Sugarcane Variety CO 421 in Kibos, Kisumu County, Kenya

“…Similar studies under similar conditions on soil bacteria and fungi have not been reported in Kenya. Dua and Sidhu [17]; Sood, et al [18] studied tea rhizosphere of Indian Himalayan regions for bacterial dominance and antagonism which indicated Bacillus bacteria of up to 45% occurrence and Pseudomonas of up to 85% occurrence to dominate the rhizosphere of established and abandoned tea bushes, respectively. In a study by Angel, et al [7]; Food and Agriculture Organization of the United Nations FAO [19] on isolation of siderosphore producing bacteria from rhizosphere soil and their antagonistic activity against selected fungal pathogens in Porur rhizosphere of tomatoes and paddy rice revealed the presence of eleven bacterial isolates which included, Fluorescent pseudomonas, Bacillus, Azobacter and non-fluorescent pseudomonas species.…”

“…From a study by [7,17] on effectiveness of rhizosphere bacteria for control of root rot disease and improving plant growth of wheat (Triticum aestivum), antagonistic rhizosphere microbes which inhibit the growth of pathogenic microorganisms have been found to colonize the plant's rhizosphere. A study by Afzal, et al [2]; Deshmukh, et al [16] in India isolated the largest number of fungi from the rhizosphere soil of sugarcane.…”