Efficacy of Bacterial endophytes against Rice pathogens under in vitro conditions

2020 ◽  
Vol 28 (3) ◽  
pp. 240-242
Author(s):  
B. Rajyalakshmi ◽  
P. Nagamani ◽  
P. Madhu Sudhan
Keyword(s):  
Bacterial Endophytes ◽  
Rice Pathogens

scholarly journals Sexually Fertile Magnaporthe grisea Rice Pathogens in Thailand

Plant Disease ◽  
1999 ◽  
Vol 83 (10) ◽  
pp. 939-943 ◽  
Author(s):  
Poonsak Mekwatanakarn ◽  
Wichai Kositratana ◽  
Tawatchai Phromraksa ◽  
R. S. Zeigler
Keyword(s):  
Mating Type ◽  
Male Fertility ◽  
Magnaporthe Grisea ◽  
Female Sterility ◽  
Diverse Populations ◽  
Type Distribution ◽  
Northern Regions ◽  
Rice Pathogens ◽  
Central Thailand

Sexual fertility and mating type distribution of Magnaporthe grisea field isolates collected in Thailand were analyzed from sites previously found to harbor diverse populations of the pathogen. Three hundred forty-one single conidium isolates of M. grisea collected from five sites in north, northeast, and central Thailand were evaluated for in vitro sexual fertility and mating type by pairing with strains of known mating type. Most isolates (67%) were infertile when crossed with the hermaphrodite tester strains; but fertile isolates of each mating type that yielded viable ascospores were detected in all sites from the northeastern and northern regions. MAT1-2 predominated over MAT1-1 in bioassay mating type. Male fertility (female sterility) predominated in fertile MAT1-1 (50 to 75%) and MAT1-2 (50 to 85%) isolates from all locations in Thailand; however, hermaphroditic and/or female fertile isolates were also detected in all but one site. Fertility, as determined by perithecia density, was low (<10 perithecia cm-2) for most isolates, although a few produced in excess of 20 perithecia cm-2.

scholarly journals Effects of bacterial endophytes from potato roots and tubers on potato cyst nematode (Globodera rostochiensis)

2018 ◽  
Vol 19 (1) ◽  
pp. 47-51 ◽  
Author(s):  
NOOR ISTIFADAH ◽  
NURHAYATI PRATAMA ◽  
SYAHRIZAL TAQWIM ◽  
TOTO SUNARTO
Keyword(s):  
Globodera Rostochiensis ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
Potato Seed ◽  
In Vitro Test ◽  
Bacterial Endophytes ◽  
Positive Effects ◽  
Bacterial Endophyte ◽  
Potato Growth

Istifadah N, Pratama N, Taqwim S, Sunarto T. 2018. Effects of bacterial endophytes from potato roots and tubers on potato cyst nematode (Globodera rostochiensis). Biodiversitas 19: 47-51. Bacterial endophytes are bacteria that inhabit plant tissues without causing any diseases. The endophytes existence may have negative, neutral, or positive effects on the host plants. This paper discusses the effects of bacterial endophytes isolated from potato roots and tubers on potato growth and their abilities to suppress potato cyst nematode, Globodera rostochiensis. The bacterial endophytes were isolated from roots and tubers of potatoes obtained from six plantation areas in West Java. The endophyte isolates were examined for their effects on potato growth. The non-pathogenic isolates were tested for their abilities to suppress G. rostochiensis in vitro and in potato plants. The results showed that from 88 bacterial endophyte isolates obtained, 13 isolates caused rot in potato seed pieces, 22 isolates inhibited the potato growth, while, 2 isolates increased the growth, and as many as 51 isolates did not influence the growth. The in vitro test using the isolate culture filtrate revealed that there were seven isolates that caused mortality of G. rostochiensis juvenile-2 by 67.5-97.7%. These isolates, however, were not effective in damaging the nematode eggs. In the greenhouse experiment, the bacterial endophyte isolates suppressed the number of cysts by 51.7-65.4% and that of the juvenile-2 of G. rostochiensis by 48.6-76.4%.

scholarly journals Efficiency of a new Waitea circinata extract against rice pathogens

2021 ◽  
Vol 51 ◽  
Author(s):  
Jacqueline Campos Borba de Carvalho ◽  
Amanda Abdallah Chaibub ◽  
Kellen Cristhina Inácio Sousa ◽  
Denise Candini de Brito ◽  
Marta Cristina Corsi de Filippi ◽  
...  
Keyword(s):  
Rice Blast ◽  
Mycorrhizal Fungus ◽  
Conidial Germination ◽  
Appressorium Formation ◽  
Vitro Assay ◽  
Rice Pathogens ◽  
Waitea Circinata ◽  
Mycelial Mass

ABSTRACT Waitea circinata (Warcup & Talbot) is an orchid antagonist mycorrhizal fungus with biocontrol potential against rice pathogens. This study aimed to optimize the extraction method, obtain a new extract and evaluate its efficiency against rice pathogens in vitro and in vivo, as well as to compare it with other extraction methods and W. circinata. The extracts were obtained and screened for in vitro growth inhibition against the pathogens Cochliobolus miyabeanus, Monographella albescens and Sarocladium oryzae, using the following extracts: mycelial, crude, lyophilized and mycelial mass. An additional in vitro assay was performed with the principal rice pathogen (Magnaporthe oryzae), in order to evaluate the conidial germination and appressorium formation. Based on this evaluation, the lyophilized and mycelial mass extracts were tested in vivo against rice blast (M. oryzae) and compared to the W. circinata mycelial suspension, in different application forms (simultaneous and previous). The mycelial mass extract inhibited all the pathogens, and the crude and lyophilized extracts inhibited C. miyabeanus and M. albescens, respectively. The mycelial mass extract inhibited the M. oryzae conidial germination and appressorium formation by 80 %, and the simultaneous and previous applications suppressed the rice blast by 94 %. These results indicate that the new extract can be used to control rice pathogens.

scholarly journals Biohardening of Tissue Cultured Banana Plantlets of cv. Ney Poovan for the Management of Fusarium wilt of Banana with Bacillus amyloliquefaciens (VB7) Triggers Defence Gene Products and Growth Promotion

2020 ◽  
pp. 352-366
Author(s):  
C. Y. Shalini Udaya ◽  
S. Nakkeeran ◽  
K. Soorianathasundaram
Keyword(s):  
Fusarium Wilt ◽  
Untreated Control ◽  
Bacillus Amyloliquefaciens ◽  
Growth Promotion ◽  
Bacterial Endophytes ◽  
Leaf Production ◽  
Control Activity ◽  
Ney Poovan ◽  
Fusarium Wilt Of Banana

Fusarium wilt of banana is the most devastating disease caused by Fusarium oxysporum f.sp. cubense (Foc). In order to combat the early onset of Fusarium wilt disease, an experiment was carried out on biohardening of tissue cultured plantlets. Six bacterial endophytes were observed to inhibit the growth of Foc in vitro. Among the six bacterial endophytes, Bacillus amyloliquefaciens (VB7) inhibited mycelial growth of Foc to an extent of 70.58% over control. Further, these bacterial endophytes were used for biohardening of the tissue cultured banana plantlets cv. Ney Poovan (AB) during primary and secondary hardening stages. Among the bacterial endophytes, B. amyloliquefaciens was found to significantly enhance plant height, leaf production, root numbers and root length compared to untreated control. Activity of defense enzymes were  also enhanced and such increase in activity was observed to be to an  extent of 93.67% in peroxidase, 92.39% polyphenol oxidase, 97.60% phenylalanine ammonia lyase  and 26.23% in β-1, 3-glucanase defence enzymes in plants biohardened with B. amyloliquefaciens (VB7) over untreated control after inoculation of Foc. Tissue cultured plants of Ney Poovan biohardened with B. amyloliquefaciens   (VB7),   B.   paraconglomeratum   (YEB   PT2) and S. maltophilia (YEB RH2) were completely free from wilt incidence symptoms upto planting stage when challenged with Foc inoculum under pot culture conditions. As among these three endophytes, B. amyloliquefaciens (VB7) also influenced favourable growth promotion, it can serve as a potential biocontrol agent for management of Fusarium wilt of banana.

scholarly journals In vitro antifungal activity of endophytic bacteria isolated from date palm (Phoenix doctylifera L.) against fungal pathogens causing leaf spot of date palm

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
H. H. Al-Nadabi ◽  
N. S. Al-Buraiki ◽  
A. A. Al-Nabhani ◽  
S. N. Maharachchikumbura ◽  
R. Velazhahan ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Endophytic Bacteria ◽  
Mycelial Growth ◽  
Fungal Pathogens ◽  
Date Palm ◽  
Dual Culture ◽  
Bacterial Endophytes ◽  
Bacterial Strains ◽  
Culture Filtrates

Abstract Background Date palm ((Phoenix doctylifera L.) suffers from several fungal diseases. The endophytic microorganisms present in higher plants generally offer protection to their host plants against invading phytopathogenic fungi and bacteria. In the present study, endophytic bacteria associated with date palm leaves were isolated and their in vitro antagonistic potential against fungal pathogens causing leaf spots in date palm was demonstrated. Results Endophytic bacteria were isolated from date palm leaves of 3 different cultivars viz., Nighal, Khalas and Khinaizi and evaluated for their inhibitory activity against leaf spot pathogens of date palm viz., Fusarium solani, Alternaria sp., Nigrospora sp., Thieloviopsis sp., Curvularia subpapendrofii and Tilletiopsis minor using an in vitro dual culture assay. Of the 24 endophytic bacterial strains tested, the endophytes designated B1, B7, B8 and B9 obtained from cv. Nighal showed inhibitory activities (more than 55% mycelial growth inhibition) against F. solani and Alternaria sp. None of the bacterial endophytes inhibited the growth of other fungal pathogens tested. These antagonistic bacterial strains were identified as Pantoea septica on the basis of 16S rRNA gene sequence analysis. The hyphae of F. solani and Alternaria sp. exhibited morphological abnormalities such as shrinkage and disintegration when grown in the presence of antagonistic bacterial endophytes. The cell-free culture filtrates of the bacterial endophytes caused inhibition of mycelial growth and induced leakage of electrolytes from the mycelia of F. solani and Alternaria sp. This is the first study that describes inhibition of the date palm pathogens F. solani and Alternaria sp. by P. septica. Conclusion Endophytic Pantoea septica strains isolated from date palm leaves inhibited the mycelial growth of F. solani and Alternaria sp. and induced morphological changes in their mycelia. The culture filtrates of these bacterial strains also inhibited the mycelial growth and caused leakage of electrolytes from the mycelia of F. solani and Alternaria sp. These promising bacterial strains can be exploited as biocontrol agents to control F. solani and Alternaria sp.-induced leaf spot diseases of date palm.

scholarly journals Plant Growth-Promoting Bacteria as an Emerging Tool to Manage Bacterial Rice Pathogens

2021 ◽  
Vol 9 (4) ◽  
pp. 682
Author(s):  
Mohamad Syazwan Ngalimat ◽  
Erneeza Mohd Hata ◽  
Dzarifah Zulperi ◽  
Siti Izera Ismail ◽  
Mohd Razi Ismail ◽  
...  
Keyword(s):  
Plant Growth ◽  
Large Scale ◽  
Plant Growth Promoting Bacteria ◽  
Promising Alternative ◽  
Rice Plants ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Rice Pathogens ◽  
Grain Losses

As a major food crop, rice (Oryza sativa) is produced and consumed by nearly 90% of the population in Asia with less than 9% produced outside Asia. Hence, reports on large scale grain losses were alarming and resulted in a heightened awareness on the importance of rice plants’ health and increased interest against phytopathogens in rice. To serve this interest, this review will provide a summary on bacterial rice pathogens, which can potentially be controlled by plant growth-promoting bacteria (PGPB). Additionally, this review highlights PGPB-mediated functional traits, including biocontrol of bacterial rice pathogens and enhancement of rice plant’s growth. Currently, a plethora of recent studies address the use of PGPB to combat bacterial rice pathogens in an attempt to replace existing methods of chemical fertilizers and pesticides that often lead to environmental pollutions. As a tool to combat bacterial rice pathogens, PGPB presented itself as a promising alternative in improving rice plants’ health and simultaneously controlling bacterial rice pathogens in vitro and in the field/greenhouse studies. PGPB, such as Bacillus, Pseudomonas, Enterobacter, Streptomyces, are now very well-known. Applications of PGPB as bioformulations are found to be effective in improving rice productivity and provide an eco-friendly alternative to agroecosystems.

scholarly journals In Vitro Efficacy of Bacterial Endophytes against Pythium sp. Causing Soft Rot of Ginger in Meghalaya

2018 ◽  
Vol 7 (08) ◽  
pp. 367-374
Author(s):  
Meshanki Bamon ◽  
Dipali Majumder ◽  
Dwipendra Thakuria ◽  
Thangaswami Rajesh
Keyword(s):  
Soft Rot ◽  
Bacterial Endophytes
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