Development of formulations of biological agents for management of root rot of lettuce and cucumber

2000 ◽  
Vol 46 (9) ◽  
pp. 809-816 ◽  
Author(s):  
G A Amer ◽  
R S Utkhede

The effect of various carrier formulations of Bacillus subtilis and Pseudomonas putida were tested on germination, growth, and yield of lettuce and cucumber crops in the presence of Pythium aphanidermatum and Fusarium oxysporum f.sp. cucurbitacearum, respectively. Survival of B. subtilis and P. putida in various carriers under refrigeration (about 0°C) and at room temperature (about 22°C) was also studied. In all carrier formulations, B. subtilis strain BACT-0 survived up to 45 days. After 45 days of storage at room temperature (about 22°C), populations B. subtilis strain BACT-0 were significantly higher in vermiculite, kaolin, and bacterial broth carriers compared with other carriers. Populations of P. putida were significantly higher in vermiculite, peat moss, wheat bran, and bacterial broth than in other carriers when stored either under refrigeration (about 0°C) or at room temperature (about 22°C) for 15 or 45 days. Germination of lettuce seed was not affected in vermiculite, talc, kaolin, and peat moss carriers, but germination was significantly reduced in alginate and bacterial broth carriers of B. subtilis compared to the non-treated control. Germination of cucumber seed was not affected by any of the carriers. Significantly higher fresh lettuce and root weights were observed in vermiculite and kaolin carriers of B. subtilis compared with P. aphanidermatum-inoculated control plants. Lettuce treated with vermiculite, and kaolin carriers of B. subtilis, or non-inoculated control lettuce plants had significantly lower root rot ratings than talc, peat moss, bacterial broth, and P. aphanidermatum-inoculated control plants. Growth and yield of cucumber plants were significantly higher in vermiculite-based carrier of P. putida than the other carriers and Fusarium oxysporum f.sp. cucurbitacearum-inoculated plants.Key words: Bacillus subtilis, Pseudomonas putida, Fusarium oxysporum f.sp. cucurbitacearum, Pythium aphanidermatum, talc, vermiculite, alginate, kaolin, peat moss, wheat bran, oat bran.

2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Manzoor R. Khan ◽  
Zaki A. Siddiqui

AbstractEffects of Pseudomonas putida and Bacillus subtilis alone, and in combinations for the management of Meloidogyne incognita, Pectobacterium betavasculorum, and Rhizoctonia solani disease complex of beetroot (Beta vulgaris L.), were studied. Application of P. putida or B. subtilis to plants with M. incognita or P. betavasculorum or R. solani singly or in combinations caused a significant increase in plant growth parameters and the activities of defense enzymes. A significant increase in chlorophyll fluorescence attributes, viz., Fv/Fm, ɸPSII, qP, NPQ, and ETR were recorded in plants treated with P. putida or B. subtilis over pathogen-inoculated plants. Inoculation of P. putida results in a higher reduction in galling and nematode multiplication than B. subtilis. Maximum reduction in nematode multiplication and galling occurred when a mixture of P. putida and B. subtilis was used. Soft rot and root rot indices were 3 when Pectobacterium betavasculorum and Rhizoctonia solani were inoculated alone. The disease indices were rated 5 when these pathogens and M. incognita were inoculated in combinations. Inoculation of P. putida/B. subtilis with P. betavasculorum or R. solani reduced soft rot and root rot indices to 2 out of 3, while the use of P. putida + B. subtilis reduced indices to 1. Disease indices were reduced to 2–3 out of 5, when P. putida + B. subtilis were used to plants inoculated with two or three pathogens. The principal component analysis showed significant correlations among the various studied attributes. Two principal components explained a total of 86.1 and 93.4% of the overall data variability. Therefore, the use of P. putida together with B. subtilis had the potential for successful management of disease complex of beetroot.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1343 ◽  
Author(s):  
Oksana Lastochkina ◽  
Darya Garshina ◽  
Chulpan Allagulova ◽  
Kristina Fedorova ◽  
Igor Koryakov ◽  
...  

In nature, plants are constantly exposed to a varied abiotic and biotic stresses or their combinations, limiting the productivity of major crops, including wheat. Combinations of drought and soil-borne Fusarium-instigated diseases are the most common combinations of stresses, significantly reducing wheat yield around the world. Here, were analyzed the potential of application of endophytic bacteria Bacillus subtilis (strain 10–4) together with the natural signal molecule salicylic acid (SA) to improve growth and tolerance of Triticum aestivum L. (wheat) plants under combined drought and Fusarium culmorum-instigated root rot (FRR) stresses. It was revealed that pre-sowing treatment with B. subtilis 10–4, SA, and B. subtilis 10–4 + SA, both under normal and combined drought conditions, notably reduced (by 50–80% or more) the incidence of FRR development in wheat plants, with the most notable effect for B. subtilis 10–4 + SA (wherein disease symptoms were almost absent). Moreover, B. subtilis 10–4, SA, and especially B. subtilis 10–4 + SA increased plant growth (root and shoot length, fresh and dry biomass) under normal (up to 20–50%), drought (up to 15–40%), FRR (up to 15–30%), and combined drought + FRR stresses (up to 20%), with the maximum effect for B. subtilis 10–4 + SA. Additionally, B. subtilis 10–4, SA, and B. subtilis 10–4 + SA decreased stress (drought, FRR, and combined drought + FRR)-instigated lipid peroxidation and osmotic damages of plant cells. The findings indicate that endophytic bacteria B. subtilis 10–4 alone and in a mixture with SA may be used as an effective eco-friendly agent to improve wheat growth and tolerance under the influence of drought, FRR, and combinations of these stresses.


2015 ◽  
Vol 40 (2) ◽  
pp. 279-289 ◽  
Author(s):  
MI Faruk ◽  
ML Rahman ◽  
MM Rahman ◽  
R Islam ◽  
MA Rahman

An investigation was undertaken to evaluate the effectiveness Trichoderma harzianum based bio-fungicides multiplied on different substrates. The substrates was rice bran, wheat bran, grass pea bran and their combinations with mustard oilcake (MOC) were used to mass culture T. harzianum for the management of foot and root rot disease of tomato seedling caused by Fusarium oxysporum in seedbed. All combinations of carrier materials were found effective for preparing T. harzianum based bio-fungicides to promote germination, seedling growth and reducing pre-emergence and post-emergence mortality of tomato seedling under F. oxysporum inoculated seedbed soils. The shoot length, shoot weight, root length and root weight of tomato seedling were enhanced significantly by the application of different substrate materials of T. harzianum based bio-fungicides under F. oxysporum inoculated seedbed conditions. The individual (rice bran, wheat bran, grass pea bran) and combination of substrates (rice bran + wheat bran, rice bran + mustard oilcake, rice bran + wheat bran + MOC and wheat bran + grass pea bran + MOC) were equally suitable for mass culturing of effective T. harzianum bio-fungicides for the management of foot and root rot disease of tomato seedling in seedbed condition.Bangladesh J. Agril. Res. 40(2): 279-289 June 2015


2021 ◽  
Author(s):  
Yunhao Sun ◽  
Bingzhi Huang ◽  
Ping Cheng ◽  
Chunji Li ◽  
Yanhong Chen ◽  
...  

The banana (Musa spp.) industry experiences dramatic annual losses from Fusarium wilt of banana (FWB) disease, which is caused by the fungus Fusarium oxysporum f. sp. cubense (FOC). Pisang Awak banana Fenza No. 1 (Musa spp. cv. Fenza No. 1), a major banana cultivar with high resistance to FOC race 4, is considered to be ideal for growth in problematic areas. However, Fenza No. 1 is still affected by FOC race 1 in the field. TR21 is an endophytic Bacillus subtilis strain isolated from orchids (Dendrobium sp.). Axillary spraying of banana plants with TR21 controls FWB, decreasing the growth period and increasing yields in the field. In this study, we established that TR21 increases root growth in different monocotyledonous plant species. By axillary inoculation, TR21 induced a similar transcriptomic change as that induced by FOC race 1 but also upregulated the biosynthetic pathways for the phytohormones brassinosteroid and jasmonate in Fenza No. 1 root tissues, indicating that TR21 increases FWB resistance, shortens growth period, and increases yield of banana by inducing specific transcriptional reprogramming and modulating phytohormone levels. These findings will contribute to the identification of candidate genes related to plant resistance against fungi in a non-model system and facilitate further study and exploitation of endophytic biocontrol agents.


Plant Disease ◽  
2009 ◽  
Vol 93 (12) ◽  
pp. 1317-1323 ◽  
Author(s):  
J. X. Zhang ◽  
A. G. Xue ◽  
J. T. Tambong

Fusarium root rot is an important disease of soybean in Ontario, Canada. This study is to select antagonistic bacterial agents as effective alternatives to chemical pesticides for the control of root rots caused by Fusarium oxysporum and F. graminearum. Twenty-two Bacillus subtilis strains from soybean and corn roots were tested in dual cultures for inhibition of mycelial growth of F. oxysporum and F. graminearum. All strains significantly reduced mycelial growth of F. oxysporum by approximately 17 to 48% and of F. graminearum by 10 to 32%. Ten B. subtilis strains selected based on their larger fungal inhibition zones were evaluated against macroconidial germination. These strains inhibited the spore germination of F. oxysporum by 20 to 48% and of F. graminearum by 14 to 32% in cell-free filtrates. Under greenhouse conditions, the efficacy of seed and soil treatments with B. subtilis strains against the two Fusarium root rot pathogens was evaluated based on root rot severity, seedling emergence, plant height, and root dry weight. Six B. subtilis strains (SB01, SB04, SB23, SB24, SB28, and SB33) from soybean roots and two strains (CB01 and CH22) from corn roots significantly reduced the severity of the two Fusarium root rots in seed or soil treatments. Strains SB01, SB04, SB23, and SB24 were the most effective treatments against both pathogens in either seed or soil treatment. When applied as seed treatments, these four strains reduced root rot severity by 43 to 63% and increased emergence by 13 to 17%, plant height by 9 to 18%, and root dry weight by 8.4 to 19%. When used as soil treatments, they reduced root rot severity by 68 to 74% and increased emergence by 14 to 18%, plant height by 11 to 23%, and root dry weight by 16 to 24%. These results suggest that the novel strains of B. subtilis identified in this research can be effective alternatives to fungicides in managing Fusarium root rots of soybean, and a greater level of efficacy may be achieved when they were used as soil treatments than seed treatments.


2011 ◽  
Vol 108 ◽  
pp. 127-131
Author(s):  
Yong Gang Li ◽  
Feng Ming Ma

. Fusarium oxysporum is a soil-borne fungus that infects soybean roots and causes soybean root rot, a widespread and destructive soybean disease. The potential strain X6 belonged to Bacillus subtilis for controlling soybean root rot. And antagonistic mechanism of the pathogenic Fusarium oxysporum of soybean root rot by B. subtilis X6 was investigated. The antagonistic mechanism of strain X6 againt F. oxysporum can effectively inhibit mycelial growth, spores bearing and germination. After treated with metabolic product of strain X6, protoplast from the hyphae became abnormal. The activity effect of metabolic product of strain X6 was sensitive to temperature. So the study lay the groundwork for further research and application.


2020 ◽  
Vol 44 (1) ◽  
pp. 304-322
Author(s):  
Aline Planchon ◽  
Gaëlle Durambur ◽  
Jean‐Baptiste Besnier ◽  
Carole Plasson ◽  
Bruno Gügi ◽  
...  

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