Growth promotion and biological control of root-knot nematodes in micropropagated banana during the nursery stage by treatment with specific bacterial strains

2008 ◽  
Vol 152 (1) ◽  
pp. 41-48 ◽  
Author(s):  
A.S. Rodríguez-Romero ◽  
E. Badosa ◽  
E. Montesinos ◽  
M.C. Jaizme-Vega
2001 ◽  
Vol 47 (10) ◽  
pp. 916-924 ◽  
Author(s):  
Tika B Adhikari ◽  
C M Joseph ◽  
Guoping Yang ◽  
Donald A Phillips ◽  
Louise M Nelson

Of 102 rhizoplane and endophytic bacteria isolated from rice roots and stems in California, 37% significantly (P [Formula: see text] 0.05) inhibited the growth in vitro of two pathogens, Achlya klebsiana and Pythium spinosum, causing seedling disease of rice. Four endophytic strains were highly effective against seedling disease in growth pouch assays, and these were identified as Pseudomonas fluorescens (S3), Pseudomonas tolaasii (S20), Pseudomonas veronii (S21), and Sphingomonas trueperi (S12) by sequencing of amplified 16S rRNA genes. Strains S12, S20, and S21 contained the nitrogen fixation gene, nifD, but only S12 was able to reduce acetylene in pure culture. The four strains significantly enhanced plant growth in the absence of pathogens, as evidenced by increases in plant height and dry weight of inoculated rice seedlings relative to noninoculated rice. Three bacterial strains (S3, S20, and S21) were evaluated in pot bioassays and reduced disease incidence by 50%–73%. Strain S3 was as effective at suppressing disease at the lowest inoculum density (106 CFU/mL) as at higher density (108 CFU/mL or undiluted suspension). This study indicates that selected endophytic bacterial strains have potential for control of seedling disease of rice and for plant growth promotion.Key words: biological control, plant growth promotion, endophytes, rice, seedling disease.


2020 ◽  
Vol 50 (4) ◽  
pp. 278-288
Author(s):  
Matheus Miranda CANIATO ◽  
Aricléia de Moraes CATARINO ◽  
Thiago Fernandes SOUSA ◽  
Gilvan Ferreira da SILVA ◽  
Karina Pryscilla de Araújo BICHARA ◽  
...  

ABSTRACT The use of bacteria in growth promotion and biological control of plant diseases can minimize environmental contamination caused by the indiscriminate use of pesticides and chemical fertilizers. We aimed to evaluate growth promotion and biological control of Corynespora cassiicola in tomato seedlings mediated by beneficial bacteria isolated from a non-rhizospheric Amazon soil containing different amounts of biochar, and to identify to which groups of bacteria the strains belong. We obtained 200 strains of bacteria from experimental plots containing biochar doses of 0, 40, 80 and 120 t ha-1. Of these, 53 strains were selected by root colonization tests. Based on growth promotion parameters, 25 strains were screened, identified by molecular characterization and evaluated for indoleacetic acid (IAA) production, phosphate solubilization and biological control. The best dose of biochar for colony formation was 40 t ha-1, and a regression model indicated 34 t ha-1 as the optimal dose. The production of IAA was observed in 18 (75%) strains, and two (8%) strains were able to solubilize phosphate. The efficiency in root growth promotion was up to 125%, and the percentage of plant protection ranged from 50 to 59%. Molecular characterization showed that the bacteria used in this study belong to the genera Bacillus and Lysinibacillus.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.


2016 ◽  
Vol 41 (3) ◽  
pp. 169-176 ◽  
Author(s):  
Sheng Jun Xu ◽  
Duck Hwan Park ◽  
Joon-Young Kim ◽  
Byung-Sup Kim

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 486 ◽  
Author(s):  
Handi Dahmana ◽  
Didier Raoult ◽  
Florence Fenollar ◽  
Oleg Mediannikov

Mosquitoes can transmit to humans devastating and deadly pathogens. As many chemical insecticides are banned due to environmental side effects or are of reduced efficacy due to resistance, biological control, including the use of bacterial strains with insecticidal activity, is of increasing interest and importance. The urgent actual need relies on the discovery of new compounds, preferably of a biological nature. Here, we explored the phenomenon of natural larvae mortality in larval breeding sites to identify potential novel compounds that may be used in biological control. From there, we isolated 14 bacterial strains of the phylum Firmicutes, most of the order Bacillales. Cultures were carried out under controlled conditions and were separated on supernatant and pellet fractions. The two fractions and a 1:1 mixture of the two fractions were tested on L3 and early L4 Aedes albopictus. Two concentrations were tested (2 and 6 mg/L). Larvae mortality was recorded at 24, 48 and 72 h and compared to that induced by the commercialized B. thuringiensis subsp. israelensis. Of the 14 strains isolated, 11 were active against the A. albopictus larvae: 10 of the supernatant fractions and one pellet fraction, and mortality increased with the concentration. For the insecticide activity prediction in three strains of the Bacillus cereus complex, PCR screening of the crystal (Cry) and cytolytic (Cyt) protein families characteristic to B. thuringiensis subsp. israelensis was performed. Most of the genes coding for these proteins’ synthesis were not detected. We identified bacterial strains that exhibit higher insecticidal activity compared with a commercial product. Further studies are needed for the characterization of active compounds.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1571
Author(s):  
Sonia Szymańska ◽  
Jarosław Tyburski ◽  
Agnieszka Piernik ◽  
Marcin Sikora ◽  
Justyna Mazur ◽  
...  

Increasing land salinization in recent decades has led to a decrease in crop productivity worldwide. We hypothesized that bioaugmentation of beetroot (Beta vulgaris) with halotolerant endophytic bacterial strains isolated from the obligatory halophytic plant Salicornia europaea L. may mitigate salt stress in new host plants. Therefore, we investigated the effects of inoculation with Pseudomonas stutzeri ISE12 or Kushneria marisflavi CSE9 on B. vulgaris growth in substrates enriched with various NaCl concentrations (0, 50, 150, 300 mM). The results of this study indicated that bioaugmentation with either bacteria resulted in improved growth parameters and increased chlorophyll content, as well as decreased proline and hydrogen peroxide concentrations, in B. vulgaris organs. However, K. marisflavi CSE9 was more efficient in achieving salt stress mitigation than P. stutzeri ISE12. In conclusion, the range of salinity tolerance seems to be a key parameter in the selection of strains for beet inoculation. The selected halotolerant endophytes (P. stutzeri ISE12 and K. marisflavi CSE9) isolated from the roots of obligatory halophytic S. europaea may be employed for plant growth promotion, especially in saline areas, and have potential applications in sustainable agriculture.


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