scholarly journals Sustainable and Ecofriendly Approach of Managing Soil Born Bacterium Ralstonia solanacearum (Smith) Using Dried Powder of Conyza canadensis

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 327
Author(s):  
Ke Chen ◽  
Raja Asad Ali Khan ◽  
Wen Cao ◽  
Meng Ling

Bacterial wilt disease caused by Ralstonia solanacearum is a devastating plant disease that inflicts heavy losses to the large number of economic host plants it infects. The potential of dried powder of the Conyza canadensis to control bacterial wilt (BW) of tomato was explored in vitro and in planta. Three application times (16 days before transplanting (DBT), 8 DBT and 0 DBT), three plastic-mulch durations (10 days plastic mulching (DPM), 5DPM and 0DPM) and four doses viz. 0 g, 8 g, 16 g and 24 g of the plant powder were evaluated. SEM analysis was also conducted to observe the change in bacterial cell morphology. Ethanol extract of dried C. canadensis in different concentrations inhibited the in vitro growth of R. solanacearum by as much as 98% of that produced by ampicillin. As evident from the scanning electron micrograph, the highest concentration produced severe morphologic changes, such as rupture of the bacterial cell walls and cell contents leaked out. Results from application time and dose experiment demonstrated that the highest powder dose viz. 24 g kg−1 mixed with infested soil 16 DBT gave maximum root length (34.0 ± 2.5 cm), plant height (74.3 ± 4.7 cm), fresh biomass (58.3 ± 4.3 g), reduction in bacterial population (1.52 log10) and resulted in lowest AUDPC value (1156.6). In case of mulching duration and dose experiment the maximum root length (39.6 ± 3.2 cm), plant height (78.3 ± 5.8 cm), fresh biomass (65.6 ± 4.9 g) reduction in bacterial population (1.59 log10) and lowest AUDPC value (1251.6) was achieved through the application of highest powder dose viz. 24 g kg−1 and longest plastic mulching duration of 10 DPM. The better results of highest dose and longer application time can be explained on the basis of higher amounts of anti-microbial plant bio-active compounds in highest dose and the longer exposure time of the pathogen to these chemicals. The better results of longer mulching duration are due to faster and more complete decomposition (because of 10-days-long plastic-mulch-provided increased solar heat) of the dried powder which produced more amounts of volatile and non-volatile bactericidal compounds. Our results clearly suggest that the use of 24 g kg−1 dried plant powder of C. canadensis plastic-mulched for two weeks could be used as a reliable component of the integrated disease management program against BW.

2015 ◽  
Vol 48 ◽  
pp. 14-22
Author(s):  
Arjun ◽  
Rao Srinath

An efficient protocol for induction of callus and regeneration of a sugar cane var 93v297 has been developed and reported here. Callus induction from immature young leaf explants derived from 2-3-month-old plants was achieved on Murashige and Skoog’s (MS) medium supplemented with different auxins viz, 2,4-D, NAA and IAA. Among different auxins, 2, 4-D at 3.5mg/l + 0.5mg/l BAP was found favourable in inducing callus. Addition of coconut milk and BAP further enhanced the growth of callus maximum being on MS medium supplemented with 0.5mg/l BAP (3602.33±0.88mg). Calli were further evaluated for regeneration. MS medium supplemented with 1.0 mg/l BAP was found suitable where 100% calli regenerated with maximum number of multiple shoots per callus mass (41.40±0.89). Highest number of root emergence (28.33±1.16) and maximum root length (3.40±0.67cm) was achieved on MS medium supplemented with 3mgl/l NAA. The in vitro grown plants were transferred to polycups containing a mixture of sterilized sand, soil and cocopeet (1:1:1) for hardening. The hardened plants were transferred to green-house conditions where they survived with 90% frequency.


2016 ◽  
Vol 8 (2) ◽  
pp. 75-78
Author(s):  
K Goswami ◽  
S Yasmin ◽  
KM Nasiruddin ◽  
F Khatun ◽  
J Akte

Plant growth regulators (PGRs) namely, 2,4-D, NAA and BAP were added into Murashige and Skoog (MS) medium to observe the effect of PGRs on the growth and development of Dendrobium sp. orchid. Leaf tips of Dendrobium sp. were used as explants and inoculated on MS medium supplemented with 2, 4 D (0, 0.5, 2.5, 5, 10 mgL?1) for development of PLBs. The maximum PLBs formation (90%) and the maximum number of PLBs (16.00) were observed in 10 mgL?1 2, 4-D into MS medium after 60 days of culture. Subcultured PLBs were inoculated on MS medium supplemented with different combinations of NAA (0, 0.5, 2.5, 5 mgL?1) and BAP (0, 0.5, 2.5, 5 mgL?1) for shoot regeneration. The maximum number of shoot (11.00), the highest fresh weight (0.6233g) and the highest shoot length (3.613 cm) were observed in 0.5 mgL?1 NAA + 0.5 mgL?1 BAP after 60 days of culture. Even, the maximum number of root (4.00), the maximum root length (1.627cm) and the maximum plantlet regeneration percentage (93.33%) were observed with the combined effect of 0.5 mg NAA and 0.5 mg BAP after 60 days of culture. Finally, regenerated plantlets were transferred into half strength MS medium to obtain plants.J. Environ. Sci. & Natural Resources, 8(2): 75-78 2015


2018 ◽  
Vol 47 (1) ◽  
pp. 162-168 ◽  
Author(s):  
Sina KEFAYETI ◽  
Ebru KAFKAS ◽  
Sezai ERCISLI

Sexual propagation is not suitable for production of true to type plants for commercial cultivation of selected cultivars due to the having heterozygous characteristics. Rubus species are highly heterozygous and therefore when they are propagated by seeds the high plant variability is obtained. Micropropagation methods became very important and have many advantages compared to the classical propagation methods. In Turkey, blackberries are commonly propagated by hard and soft wood cuttings, by layering and bush division. Propagation by layers requires rather large area for a layered, and weed control among the layers is a problem. However, propagation by cuttings is connected with important problem in inadequate rooting, especially in ‘Chester Thornless’ cultivar, which is one of the most commercially grown cultivar. In addition, limited number of plants can be propagated using classical propagation method and thus demand of growers for the plants can not be satisfied. Optimized and highly efficient regeneration protocols are also important for genetic transformation for improving of new cultivars. In this study we focused on optimization of protocol for in vitro propagation of ‘Chester Thornless’ blackberry cultivar using nodal segments. For this purpose, explants were cultured on Woody Plant Medium (WPM) supplemented with combination of plant growth regulators BAP (1.5, 2, 3 mg/l) with NAA (0, 0.1, 0.2, 0.4 mg/l) to detect the best multiplication medium. According to the obtained results, the highest proliferation rate was obtained for cultivar ‘Chester Thornless’ that produced 9.66 shoots on a medium containing 2 mg/I BAP+0.2 mg/I IBA combination. GA3 effects on multiplication rates were also studied and generally the highest rates obtained by while GA3 were not used. For the rooting, different concentrations of IBA and NAA (0, 0.1, 0.2 and 0.4 mg/I) were compared. A concentration of 0.4 mg/l NAA gave the greatest number of roots and maximum root length.


2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Derek Fleming ◽  
Laura Chahin ◽  
Kendra Rumbaugh

ABSTRACT The persistent nature of chronic wounds leaves them highly susceptible to invasion by a variety of pathogens that have the ability to construct an extracellular polymeric substance (EPS). This EPS makes the bacterial population, or biofilm, up to 1,000-fold more antibiotic tolerant than planktonic cells and makes wound healing extremely difficult. Thus, compounds which have the ability to degrade biofilms, but not host tissue components, are highly sought after for clinical applications. In this study, we examined the efficacy of two glycoside hydrolases, α-amylase and cellulase, which break down complex polysaccharides, to effectively disrupt Staphylococcus aureus and Pseudomonas aeruginosa monoculture and coculture biofilms. We hypothesized that glycoside hydrolase therapy would significantly reduce EPS biomass and convert bacteria to their planktonic state, leaving them more susceptible to conventional antimicrobials. Treatment of S. aureus and P. aeruginosa biofilms, grown in vitro and in vivo, with solutions of α-amylase and cellulase resulted in significant reductions in biomass, dissolution of the biofilm, and an increase in the effectiveness of subsequent antibiotic treatments. These data suggest that glycoside hydrolase therapy represents a potential safe, effective, and new avenue of treatment for biofilm-related infections.


2000 ◽  
Vol 66 (1) ◽  
pp. 118-124 ◽  
Author(s):  
D. John I. Thomas ◽  
J. Alun W. Morgan ◽  
John M. Whipps ◽  
Jon R. Saunders

ABSTRACT Plasmid transfer between Bacillus thuringiensis subsp.kurstaki HD1 and B. thuringiensis subsp.tenebrionis donor strains and a streptomycin-resistantB. thuringiensis subsp. kurstaki recipient was studied under environmentally relevant laboratory conditions in vitro, in soil, and in insects. Plasmid transfer was detected in vitro at temperatures of 5 to 37°C, at pH 5.9 to 9.0, and at water activities of 0.965 to 0.995, and the highest transfer ratios (up to 10−1 transconjugant/donor) were detected within 4 h. In contrast, no plasmid transfer was detected in nonsterile soil, and rapid formation of spores by the introduced strains probably contributed most to the lack of plasmid transfer observed. When aB. thuringiensis subsp. kurstaki strain was used as the donor strain, plasmid transfer was detected in killed susceptible lepidopteran insect (Lacanobia oleracea) larvae but not in the nonsusceptible coleopteran insect Phaedon chocleriae. When a B. thuringiensis subsp.tenerbrionis strain was used as the donor strain, no plasmid transfer was detected in either of these insects even when they were killed. These results show that in larger susceptible lepidopteran insects there is a greater opportunity for growth of B. thuringiensis strains, and this finding, combined with decreased competition due to a low initial background bacterial population, can provide suitable conditions for efficient plasmid transfer in the environment.


2015 ◽  
Vol 60 (3) ◽  
pp. 263-275 ◽  
Author(s):  
Fardin Nasri ◽  
Arsalan Fadakar ◽  
Mahmood Saba ◽  
Bayzid Yousefi

Rosa damascena is very important for essential oil production, medicinal properties and it is also widely cultivated as a garden rose. The Rose species is mainly propagated by stem cutting. In the present study, the effect of different levels of 0, 500 and 1,000 mg l-1 (quick dip method for 20 s) of indole butyric acid (IBA) on the rooting of 12 wild genotypes (including: Kurdistan 1 to Kurdistan 12) of R. damascena was investigated. The results show that the rooting ability of R. damascena differs significantly between the twelve genotypes. The highest rooting (79.56%) and callus production (69.08%), number of roots (8.33), root fresh and dry weights (361.80 and 244.74 mg, respectively) were recorded in Kurdistan 5 genotype with 1,000 mg l-1 IBA. The maximum root length (5.84 cm) was observed in Kurdistan 5 genotype with 500 mg l-1 IBA that showed a significant difference compared to the control treatment (0.96 cm). The highest number of leaves per bud (7.33 at 500 mg l-1 IBA) and number of buds (5.00 at 1,000 mg l-1 IBA) were recorded in Kurdistan 1 genotype. The current study demonstrated that the different genotypes of R. damascena were in a difficult-toroot state, which suggests that cutting treatment with 1,000 mg l-1 IBA overcame the problem of the difficult-to-root state, and it can also enhance the rooting percentage in the studied genotypes.


2015 ◽  
Vol 3 (2) ◽  
pp. 243-247 ◽  
Author(s):  
Varsha Dawande ◽  
Rajaram Gurav

Asymbiotic seed germination of Eulophia nuda Lindl. was observed on Knudson C medium. About 90% seeds germinated within 8-10 weeks and formed green protocorms in 11-12 weeks. Effect of BA and IBA was studied on plantlet development from protocorms. BA shows the best results with respect to number and length of shoots. Maximum number (6.45±1.36) and length (3.90±0.99) was observed on MS medium supplemented with 4.44μM.BA. Maximum root growth was also observed on same medium (4.8±0.99 number of roots and 1.43±0.13cm length). The regenerated plantlets were successfully acclimatized and transferred to earthen pots. The results presented here show that in vitro seed germination and plantlet development in Eulophia nuda Lindl., an endangered orchid, can be achieved at a higher rate by this method.Int J Appl Sci Biotechnol, Vol 3(2): 243-247 DOI: http://dx.doi.org/10.3126/ijasbt.v3i2.12476   


Nativa ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
Marcos Vinícius Marques Pinheiro ◽  
Ana Cristina Portugal Pinto De Carvalho ◽  
Fabrina Bolzan Martins

No intuito de elevar as taxas de sobrevivência durante a etapa de aclimatização e posterior plantio a campo, avaliou-se o enraizamento in vitro de bananeira cv. Pacovan, em diferentes concentrações de sais MS e de sacarose. Utilizou-se DIC, esquema fatorial (6x2x3), com seis meios de cultura [sendo três concentrações de nutrientes do meio MS (100%; 50% de macronutrientes; e 50% dos sais macro e micronutrientes), e duas concentrações de sacarose (1,5/3,0%)], dois fotoperíodos (12/16 h) e três tempos de cultivo (21, 28 ou 35 dias) e seis repetições/tratamento. Analisaram-se: altura da planta, número de folhas/planta, massas frescas e secas das partes aérea e radicular. Para altura da planta, massa fresca da parte aérea e radicular, o meio MS 50% dos sais + sacarose (1,5%) com fotoperíodo de 16 h e tempo de cultivo de 35 dias foi satisfatório. Para massa seca da parte aérea foi MS 50% de sais + sacarose (3%), e para massa seca da parte radicular, MS 100% + sacarose (3%) (em 12hs/28 dias e 16hs/21 dias). Para o alongamento/enraizamento in vitro da bananeira cv. Pacovan sugere-se MS 50% de sais (macro e micronutrientes), redução ou manutenção de sacarose (1,5 ou 3%) em 16h/35 dias de cultivo.Palavra-chave: Musa spp., propagação in vitro, sistema radicular. CHANGES IN CULTURE MEDIUM, PHOTOPERIOD AND TIME OF CULTIVATION AFFECT THE IN VITRO ELONGATION AND ROOTING OF BANANA CV. PACOVAN ABSTRACT:In order to achieve high rates of survival during the acclimatization and later planting in the field, was evaluated the in vitro of banana cv. Pacovan plants under different concentrations of sucrose and MS basal salt mixture. The experiment was assembled in a DIC, in 6x2x3, six different culture media [three different MS salt mixture concentrations (100%; 50% of macronutrients; and 50% of macro/micronutrients) and two sucrose concentrations (1.5/3%)], two photoperiods (12/16 hours) and three cultivation times (21, 28 or 35 days). Each treatment was composed by 6 replicates. Plant height, number of leaves/plant, fresh and dry weight of roots and shoots, were analyzed. Satisfactory results for plant height and shoot and root fresh biomass were observed in MS with macro/micronutrients (50%) + sucrose (3%), 16 hours/35 days. The highest values of shoot dry weight were observed in MS with macro/micronutrients (50%) + sucrose (3%); the highest root dry weight was achieved with MS 100% + sucrose (3%) (12hs/28 and 16hs/21 days). The suggested medium for the in vitro elongation and rooting stage of banana cv. Pacovan is the MS with 50% of salts (macro and micronutrients), reduction or maintenance of sucrose (1.5 or 3%) in 16h/35 days of cultivation.Keywords: Musa spp., in vitro propagation, root system. DOI:


Plant Disease ◽  
2020 ◽  
Vol 104 (10) ◽  
pp. 2613-2621
Author(s):  
Raja Asad Ali Khan ◽  
Syed Sartaj Alam ◽  
Sania Hayat ◽  
Musharaf Ahmad ◽  
Asad Ali ◽  
...  

Bacterial wilt (BW) disease caused by Ralstonia solanacearum species complex is a devastating plant disease that inflicts heavy losses to the large number of economic host plants it infects. In this study, the potential of dried powder of the arid-land medicinal shrub Rhazya stricta to control BW of tomato was explored. Both, in vitro and in planta studies were conducted, using different concentrations of dried powder of plant parts, and applied (surface mulched or mixed) to infested soil at 0, 10, and 20 days before transplanting (DBT). Aqueous extract of leaves (16% w/v) was found to be as effective as streptomycin (100 ppm) in inhibiting the in vitro growth of R. solanacearum. As evident from the scanning electron micrograph, 16% aqueous extract of leaves produced severe morphological changes, such as rupture of the bacterial cell walls. Results from the greenhouse experiments demonstrated that the higher powder dose (succulent shoot), namely, 30 g/kg of soil mixed with infested soil 20 DBT, was found to be the most effective in controlling BW. It increased root length (cm), shoot length (cm), and plant fresh biomass (g) by 55, 42, and 40%, respectively, over control plants. Mixing of plant powder with the artificially infested (35 ml of 108 CFU/ml per kilogram of soil) pot soil was better than surface mulching. The 30 g/kg of soil dose mixed with soil increased root length (cm), shoot length (cm), and plant fresh biomass (g) of treated plants by 67, 36, and 46%, respectively, over control plants. A 37% decrease in disease severity over the control was observed with drench application of 30 g of powder per kilogram of soil applied once at 20 DBT. Our results indicated that the dried powder (30 g/kg of soil) of leaves or succulent shoots of R. stricta, thoroughly mixed with soil, 20 DBT, could act as an effective control method against BW.


Nematology ◽  
2001 ◽  
Vol 3 (8) ◽  
pp. 729-734 ◽  
Author(s):  
C.J.(Hans) Kok ◽  
Artemis Papert ◽  
C.B.(Chula) Bok-A-Bin

AbstractEgg masses of Meloidogyne fallax from tomato and potato growing in soil from a nematode suppressive and a nonsuppressive field sustained bacterial population densities two to three orders of magnitude higher than those of the rhizosphere soil. BIOLOG metabolic profiling identified 16 bacterial species from egg masses. Results further indicated 20 species not listed in the BIOLOG database. 122 isolates of bacteria and 19 isolates of fungi from M. fallax or M. hapla were tested for in vitro antagonism against the nematode egg parasitic fungus Verticillium chlamydosporium: 23% of the bacteria and 74% of the fungi showed antagonistic activity. Pseudomonads showed an overall stronger antagonistic activity than the other bacteria. Our conclusions are that Meloidogyne egg masses are a densely populated microbial niche and that their microflora may well be an important factor in determining the success of nematode antagonists. However, we could not find a relationship between the egg mass microflora and differences in soil suppressiveness between the sample sites.


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