Effects of Meloidogyne incognita, Pectobacterium betavasculorum and Rhizoctonia solani interactions on growth, physiological and biochemical changes of beetroot

2020 ◽  
pp. 1-18
Author(s):  
Manzoor R. Khan ◽  
Zaki A. Siddiqui

Abstract Effect of Meloidogyne incognita, Pectobacterium betavasculorum and Rhizoctonia solani alone, pre, post and simultaneous inoculations to find out role of each pathogen on growth, chlorophyll and carotenoid, superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione reductase (GR) activities and proline, H2O2 and malondialdehyde (MDA) of beetroot (Beta vulgaris L). Inoculation of plants with M. incognita / P. betavasculorum or R. solani reduced plant growth (root dry weight) (42.0%), chlorophyll (24.2%) and carotenoid (47.7%) while inoculation of pathogens under study resulted in increased activities of antioxidant enzymes, proline, H2O2 and MDA. Combined inoculation of pathogens under study resulted in greater reduction of plant growth (74.9%), chlorophyll (55.3%) and carotenoid (83.7%) than individual pathogen. Greatest reduction in plant growth, chlorophyll and carotenoid and maximum activities of antioxidant enzymes, proline, H2O2 and MDA were observed when M. incognita was inoculated 20 days prior to P. betavasculorum plus R. solani. P. betavasculorum and R. solani reduced galling and nematode multiplication but maximum reduction in galling (82.8%) and nematode multiplication (82.7%) was observed when P. betavasculorum plus R. solani were inoculated prior to nematodes. Necrosis soft rot and root rot indices by P. betavasculorum and R. solani were 3 respectively. Disease indices were 5 when two or more pathogens were inoculated together. Prior inoculation of M. incognita predisposed beetroots to P. betavasculorum and R. solani and aggravates the disease.

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.


2020 ◽  
Vol 8 (4) ◽  
pp. 496
Author(s):  
Dilfuza Egamberdieva ◽  
Vyacheslav Shurigin ◽  
Burak Alaylar ◽  
Hua Ma ◽  
Marina E. H. Müller ◽  
...  

The effects of biochar on plant growth vary depending on the applied biochar type, study site environmental conditions, microbial species, and plant–microbial interactions. The objectives of the present study were therefore to assess 1) the response of growth parameters of lupin and root disease incidence to the application of three biochar types in a loamy sandy soil, and 2) the role of endophytic bacteria in biological control of root rot disease incidence in lupin after the amendment of soil with different biochar types. As biochar types we tested (i) hydrochar (HTC) from maize silage, (ii) pyrolysis char from maize (MBC), and (iii) pyrolysis char from wood (WBC) at three different concentrations (1%, 2%, and 3% of char as soil amendments). There were no significant effects in lupin shoot and root growth in soils amended with WBC at any of the concentrations. MBC did not affect plant growth except for root dry weight at 2% MBC. HTC char at 2% concentration, significantly increased the root dry weight of lupin by 54–75%, and shoot dry weight by 21–25%. Lupin plants grown in soil amended with 2% and 3% WBC and MBC chars showed 40–50% and 10–20% disease symptoms, respectively. Plants grown in soil without biochar and with HTC char were healthy, and no disease incidence occurred. Pseudomonas putida L2 and Stenotrophomonas pavanii L8 isolates demonstrated a disease reduction compared to un-inoculated plants under MBC and WBC amended soil that was infested with Fusarium solani.


1984 ◽  
Vol 30 (12) ◽  
pp. 1440-1447 ◽  
Author(s):  
Craig S. Rothrock ◽  
David Gottlieb

Streptomyces hygroscopicus var. geldanus controlled rhizoctonia root rot of pea in previously sterilized soil if incubated for 2 or more days prior to infesting soil with Rhizoctonia solani and planting. Streptomyces hygroscopicus also reduced saprophytic growth and the population of R. solani in soil. Growth of R. solani was inhibited by geldanamycin, an antibiotic produced by S. hygroscopicus, on nutrient media. Methanol extracts of soils in which the antagonist was incubated for 2 or more days inhibited growth of R. solani. Geldanamycin concentration was 88 μg per gram of soil after 7 days of incubation. Bioautography of soil extracts indicated that the inhibitory compounds were geldanamycin and two other compounds, also found in the geldanamycin standard. The period of incubation necessary for antibiotic production and disease control was similar, with no disease control occurring where no antibiotic was detected. Amending soil with geldanamycin, in amounts equivalent to that produced after 2 or 7 days of incubation, controlled disease and reduced saprophytic growth of the pathogen. Lesser amounts of the antibiotic did neither. No evidence for antagonism owing to competition (nitrogen, carbon) or parasitism was found. Streptomyces hygroscopicus and geldanamycin also affected plant growth.


2014 ◽  
Vol 30 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Syed Ehteshamul-Haque ◽  
Abdul Ghaffar

Seed treatment of soybean with <i>Bndyrhizobium japonicum, Trichoderma harzianum, T. viride, T. hamatum, T. koningii</i> and <i>T. pseudokoningii</i> significantly controlled the infection of 30-day-old seedlingsby <i>Maerophomina phaseolina, Rhizoctonia solani</i> and <i>Fusarium</i> spp. In 60-day-old plants <i>Trichoderma</i> spp.. and <i>B. japonicum</i> inhibited the grouth of <i>R. solani</i> and <i>Fusarium</i> spp., whereas the use of <i>B. japonicum</i> (TAL-102) with <i>T. harzianum. T. viride, T. koningii</i> and <i>T. pseudokoningii</i> controlled the infection by <i>M. phaseolina. Greater grain yield was recorded when B. <i>japonium</i> (TAI-102) was used with <i>T. hamatum</i>.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1013D-1013
Author(s):  
Yan Chen ◽  
Donald Merhaut ◽  
J. Ole Becker

Nitrogen (N) fertilization is critical for successful production of cut flowers in a hydroponic system. In this study, two sunflower cultivars: single-stand `Mezzulah' and multi-stand `Golden Cheer' were grown under two N fertilization rates: 50 mg·L-1 and 100 mg·L-1 in a recirculating hydroponic system. At the same time, `Mezzulah' sunflowers were biologically stressed by exposing each plant to 2000 second-stage juveniles of the plant parasitic nematode Meloidogyne incognita, race 1. The experiment was conducted in May and repeated in Sept. 2004, and plant growth and flower quality between control and nematode-infested plants were compared at the two N rates. The two cultivars responded differently to fertilization treatments. With increasing N rate, the dry weight of `Mezzulah' increased, while that of `Golden Cheer' decreased. Flower size and harvest time were significantly different between the two cultivars. However, N had no effect on flower quality and harvest time. Flower quality rating suggests that quality cut stems can be obtained with 50 mg·L-1 N nutrient solution. Nematode egg count suggests that plants in the nematode treatment were successfully infested with Meloidogyne incognita, however, no significant root galling was observed, and plant growth and flower quality were not affected by nematode infestation.


2019 ◽  
Vol 76 ◽  
pp. 111-123
Author(s):  
Ertran Yildirim ◽  
Melek Ekinci ◽  
Raziye Kul ◽  
Metin Turan ◽  
Ayla Gür

The study was conducted to determine effects of a new synthesis of methylamine on the plant growth, physiological and biochemical characteristics in pepper.  There were four irrigation levels [full irrigation (100%) (I0), 80% (I1), 60% (I2) and 40% (I3)] and two methylamine (MA) treatments (0, 2.5 mM). At the end of the study, it was observed that there were significant differences between applications and levels. Effects of MA treatments on plant growth (plant height, stem diameter, fresh, dry weight etc.), plant physiological and biochemical parameters [tissue electrical conductivity (TEC), tissue relative water content (TRWC), hydrogen peroxide (H2O2), malondialdehyde (MDA), proline, antioxidant enzyme activity], and plant nutrient element content of pepper seedlings under different irrigation levels were significantly important.  The results of the study showed that the drought stress conditions negatively affected the plant growth, increased the content of TEC, H2O2 and MDA, and decreased the TRWC and  plant mineral content in pepper. However, MA application improved plant growth and decreased TEC, H2O2 and MDA content compared to control in pepper under drought conditions. MA treated plants at I3 had higher shoot fresh weight and shoot dry weight than non-treated plants by 12 and 20%, respectively.  In conclusion, MA application could mitigate the deleterious effects of the drought stress on the pepper seedlings.


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