Wilt Disease In Chickpea Research Articles

Evaluation of Streptomyces sp. obtained from herbal vermicompost for broad spectrum of plant growth-promoting activities in chickpea

Five strains of Streptomyces sp. (CAI-24, CAI-121, CAI-127, KAI-32, and KAI-90; demonstrated previously to have potential for control of Fusarium wilt disease in chickpea and plant growth promotion [PGP] in rice) were evaluated for their PGP capabilities in chickpea in the 2012–2013 and 2013–2014 post-rainy seasons. The plots inoculated with Streptomyces sp. significantly enhanced number of nodule, nodule weight, root weight, and shoot weight at 30 days after sowing (DAS) and number of pod, pod weight, leaf area, leaf weight, and stem weight at 60 DAS in both seasons over the un-inoculated control plots. At chickpea crop maturity, all of the Streptomyces strains significantly enhanced stover yield, grain yield, and total dry matter in both seasons over the un-inoculated control. In the rhizosphere, the Streptomyces strains also significantly enhanced soil biological and mineral nutrient activities including microbial biomass carbon, dehydrogenase activity, total nitrogen, available phosphorous, and organic carbon in both seasons over the un-inoculated control. All of the five strains were found superior in terms of nodule formation, root and shoot development, and crop productivity; however, KAI-xx had little edge over the other five strains. Scanning electron microscopy (SEM) analysis had revealed the success of colonization by the strains of Streptomyces sp. of the chickpea roots. Quantitative real-time PCR (qRT-PCR) analysis of selected PGP genes revealed overall upregulation of β-1,3-glucanase, indole-3-acetic acid, and siderophore genes in the Streptomyces species studied. This investigation further confirms the broad spectrum of PGP activities by the selected Streptomyces sp.

Synergistic effect of antagonistic microflora and farmyard manure (FYM) to reduce wilt disease in chickpea caused by Fusarium oxysporum f sp ciceri

Wilt disease of chickpea caused by Fusarium oxysporum f sp ciceri (Pudwick) Synd. and Hans. is serious problems across the country. The experiment was conducted at the farm College of Agriculture, Rajasthan Agricultural University, Bikaner in for two crop seasons 2007-08 and 2008-09 to manage the wilt disease of chickpea. Chickpea variety RSG- 44 was used for this experiment. For the purpose, two antagonist, i.e. Trichoderma harzianum and Pseudomonas fluorescens were applied as seed treatment (alone @ 8 g/ kg seeds; in combination of both bioagents @ 4 g + 4 g/ kg seeds) and soil application (alone @ 10 kg/ ha; in combination of both bioagents @ 5 kg + 5 kg/ ha) along with FYM @ 5, 10, and 15 tonnes/ ha in the field. Minimum wilt disease incidence 23.65% and 25.35% was found in the treatment T12: T. harzianum+P. fluorescens seed treatment (4+4) kg/seed) and soil application (5+5) kg/ha along with FYM @15 tonnes/ h followed by T11:T. harzianum +P. fluorescens seed treatment (4+4) kg/seed) and soil application (5+5) kg/ha along with FYM @10 tonnes/ ha (27.67 and 28.61%) and T8: P. fluorescens ST (8 g/ kg seed + SA (10 kg/ h + FYM 15 tonnes/ha (28.51 and 29.48%) in 2007-08 and 2008-09 under field conditions respectively. The plant growth, i.e. root and shoot lengths, dry weight and seed yield were found higher when T. harzianum and P. fluorescens were used along with higher dose of FYM, i.e. 15 tonnes/ha. A significant variation was recorded among the treatments. The organic carbon content of the soil was increased by increasing the dose of FYM from 5 to 15 tonnes/h irrespective of bioagents. The Fusarium population was suppressed by the two bioagents used alone or in combinations. The population of T. harzianum and P. fluorescens was higher in rhizosphere soil when FYM was applied at higher dose (15 tonnes/ha). Our result findings indicate that microbial bioagents and FYM have synergistic effect on reducing the wilt incidence in chickpea and promote the plant growth significantly.

Plant growth-promoting traits of Pseudomonas geniculata isolated from chickpea nodules.

A bacterium, isolated from nodules of chickpea grown in alluvial soils of Haryana state of India, designated as IC-76 was characterized for in vitro plant growth-promoting (PGP) properties and further evaluated under greenhouse, on-station and on-farm field conditions for PGP activity in chickpea. The isolate IC-76 produced indole acetic acid, siderophore, hydrocyanic acid, cellulase, protease, and β-1,3-glucanase. When the bacterium was evaluated individually for their PGP potential in the greenhouse on chickpea and in combination with five Streptomyces sp. (strains CAI-24, CAI-121, CAI-127, KAI-32, and KAI-90; demonstrated earlier as biocontrol potential against Fusarium wilt disease in chickpea), the traits, including nodule number and weight, shoot, and root weight, pod number and weight, seed number and weight, available phosphorus and % organic carbon were found significantly, enhanced over un-inoculated control. In the on-station and on-farm field conditions, IC-76 significantly enhanced nodule number and weight, shoot, and root weight, stover and grain yield and total dry matter. In the rhizosphere (0–15 cm soil), the bacterium also significantly enhanced the total nitrogen, available phosphorus and % organic carbon. The sequence of 16S rDNA gene of the IC-76 was matched with Pseudomonas geniculata in BLAST analysis. This study demonstrates that IC-76 has the potential for PGP in chickpea.

Evaluation of actinomycete isolates obtained from herbal vermicompost for the biological control of Fusarium wilt of chickpea

A total of 137 actinomycetes cultures, isolated from 25 different herbal vermicomposts, were characterized for their antagonistic potential against Fusarium oxysporum f. sp. ciceri (FOC) by dual-culture assay. Of the isolates, five most promising FOC antagonistic isolates (CAI-24, CAI-121, CAI-127, KAI-32 and KAI-90) were characterized for the production of siderophore, cellulase, protease, hydrocyanic acid (HCN), indole acetic acid (IAA) and antagonistic potential against Rhizoctonia bataticola, which causes dry root rot in chickpea (three strains viz. RB-6, RB-24 and RB-115) and sorghum (one strain). All of the five FOC antagonistic isolates produced siderophore and HCN, four of them (except KAI-90) produced IAA, KAI-32 and KAI-90 produced cellulase and CAI-24 and CAI-127 produced protease. In the dual-culture assay, three of the isolates, CAI-24, KAI-32 and KAI-90, also inhibited all three strains of R. bataticola in chickpea, while two of them (KAI-32 and KAI-90) inhibited the tested strain in sorghum. When the FOC antagonistic isolates were evaluated further for their antagonistic potential in the greenhouse and wilt-sick field conditions on chickpea, 45–76% and 4–19% reduction of disease incidence were observed, respectively compared to the control. The sequences of 16S rDNA gene of the isolates CAI-24, CAI-121, CAI-127, KAI-32 and KAI-90 were matched with Streptomyces tsusimaensis, Streptomyces caviscabies, Streptomyces setonii, Streptomyces africanus and an identified species of Streptomyces, respectively using the BLAST searching. This study indicated that the selected actinomycete isolates have the potential for biological control of Fusarium wilt disease in chickpea.

Development of Formulations ofPseudomonas fluorescensfor Control of Chickpea Wilt

Pseudomonas fluorescens strains were obtained from the rhizosphere of different crops and strains that showed inhibitory action against the chickpea (Cicer arietinum) wilt pathogen Fusarium oxysporum f. sp. ciceris were selected for further studies. The efficacy of various carriers in sustaining the population of these strains in storage was assessed. In talc-based and peat-based formulations the bacteria survived even up to 240 days of storage although the population declined from 30 days. When chickpea seeds were treated with talc-based formulations, P. fluorescens survived on the seeds for at least 180 days. When the treated seeds were sown in soil, the antagonist moved to the rhizosphere and survived well in it. Biopriming of seeds increased rhizosphere population. Seed treatment with the antagonist formulation effectively controlled chickpea wilt disease in the two field trials and increased the yield. When seed treatment was followed by root zone application the efficacy of P. fluorescens formulations increased. Pseudomonas fluorescens did not inhibit the beneficial N-fixing bacteria Rhizobium and Azospirillum in vitro and seed treatment fungicides (thiram and carbendazim) were not inhibitory to P. fluorescens in vitro.