scholarly journals Bacteria occurring in onion (Allium cepa L.) foliage in Puerto Rico.

1969 ◽  
Vol 96 (3-4) ◽  
pp. 199-219 ◽  
Author(s):  
Juan Calle-Bellido ◽  
Lydia I. Rivera-Vargas ◽  
Myrna Alameda ◽  
Irma Cabrera
Keyword(s):  
Puerto Rico ◽  
Pseudomonas Syringae ◽  
Allium Cepa ◽  
Leaf Tissue ◽  
Field Conditions ◽  
Bacterial Strains ◽  
Burkholderia Glumae ◽  
Pathogenic Potential ◽  
Allium Cepa L ◽  
Leaf Tissues

Bacteria associated with foliar symptoms of onion (Allium cepa L.) were examined in the southern region of Puerto Rico from January through April 2004. Different symptoms were observed in onion foliage of cultivars 'Mercedes' and 'Excalibur' at Juana Díaz and Santa Isabel, Puerto Rico. Ellipsoidal sunken lesions with soft rot and disruption of tissue were the most common symptoms observed in onion foliage in field conditions. From a total of 39 bacterial strains isolated from diverse symptoms in onion foliage, 38% were isolated from soft rotting lesions. Ninety-two percent of the bacteria isolated from onion foliage was Gram negative. Pantoea spp. with 25%, was the most frequently isolated genus, followed by Pasteurella spp. and Serratia rubidae with 10% each. Fifty- six percent of the strains held plant pathogenic potential; these strains belong to the genera Acidovorax sp., Burkholderia sp., Clavibacter sp., Curtobacterium sp., Enterobacter sp., Pantoea spp., Pseudomonas spp., and Xanthomonas spp. Pathogenicity tests showed that seven out of eight tested bacterial strains evaluated under field conditions caused symptoms in onion foliage for both cultivars. Acidovorax avenae subsp. citrulli, Burkholderia glumae, Pantoea agglomerans, P. dispersa, Pseudomonas sp., Xanthomonas sp., and Xanthomonas-like sp. were pathogenic to leaf tissues. Clavibacter michiganensis was not pathogenic to leaf tissues. Other bacteria identified as associated with onion leaf tissue were Curtobacterium flaccumfaciens, Cytophaga sp., Enterobacter cloacae, Flavimonas oryzihabitans, Mannheimia haemolytica, Pantoea stewartii, Pasteurella anatis, P. bettyae, P. langaaensis, Photobacterium damselae, Pseudomonas syringae pv. aptata, Rhizobium radiobacter, Serratia rubidae, Sphingobacterium spiritivorum, Sphingomonas sanguinis, and an unknown strain. This paper is the first survey of bacteria associated with onion foliage in Puerto Rico. The role of non- phytopathogenic bacteria associated with the life cycle of onion under field conditions remains unknown.

Bacteria occurring in onion (Allium cepa L.) foliage in Puerto Rico.

1969 ◽  
pp. 199-219
Author(s):  
Juan Calle-Bellido ◽  
Lydia I. Rivera-Vargas ◽  
Myrna Alameda ◽  
Irma Cabrera
Keyword(s):  
Puerto Rico ◽  
Pseudomonas Syringae ◽  
Allium Cepa ◽  
Leaf Tissue ◽  
Field Conditions ◽  
Bacterial Strains ◽  
Burkholderia Glumae ◽  
Pathogenic Potential ◽  
Allium Cepa L ◽  
Leaf Tissues

Bacteria associated with foliar symptoms of onion (Allium cepa L.) were examined in the southern region of Puerto Rico from January through April 2004. Different symptoms were observed in onion foliage of cultivars 'Mercedes' and 'Excalibur' at Juana Díaz and Santa Isabel, Puerto Rico. Ellipsoidal sunken lesions with soft rot and disruption of tissue were the most common symptoms observed in onion foliage in field conditions. From a total of 39 bacterial strains isolated from diverse symptoms in onion foliage, 38% were isolated from soft rotting lesions. Ninety-two percent of the bacteria isolated from onion foliage was Gram negative. Pantoea spp. with 25%, was the most frequently isolated genus, followed by Pasteurella spp. and Serratia rubidae with 10% each. Fifty- six percent of the strains held plant pathogenic potential; these strains belong to the genera Acidovorax sp., Burkholderia sp., Clavibacter sp., Curtobacterium sp., Enterobacter sp., Pantoea spp., Pseudomonas spp., and Xanthomonas spp. Pathogenicity tests showed that seven out of eight tested bacterial strains evaluated under field conditions caused symptoms in onion foliage for both cultivars. Acidovorax avenae subsp. citrulli, Burkholderia glumae, Pantoea agglomerans, P. dispersa, Pseudomonas sp., Xanthomonas sp., and Xanthomonas-Wke sp. were pathogenic to leaf tissues. Clavibacter michiganensis was not pathogenic to leaf tissues. Other bacteria identified as associated with onion leaf tissue were Curtobacterium flaccumfaciens, Cytophaga sp., Enterobacter cloacae, Flavimonas oryzihabitans, Mannheimia haemolytica, Pantoea stewartii, Pasteurella anatis, P. bettyae, P. langaaensis, Photobacterium damselae, Pseudomonas syringae pv. aptata, Rhizobium radiobacter, Serratia rubidae, Sphingobacterium spiritivorum, Sphingomonas sanguinis, and an unknown strain. This paper is the first survey of bacteria associated with onion foliage in Puerto Rico. The role of non- phytopathogenic bacteria associated with the life cycle of onion under field conditions remains unknown.

The 73-kb pIAA plasmid increases competitive fitness of Pseudomonas syringae subspecies savastanoi in oleander

1993 ◽  
Vol 39 (7) ◽  
pp. 659-664 ◽  
Author(s):  
Sara E. Silverstone ◽  
David G. Gilchrist ◽  
Richard M. Bostock ◽  
Tsune Kosuge
Keyword(s):  
Population Density ◽  
Pseudomonas Syringae ◽  
Indoleacetic Acid ◽  
Leaf Tissue ◽  
Insertion Mutant ◽  
Wild Type ◽  
In Planta ◽  
Bacterial Strains ◽  
Growth And Survival ◽  
Iaa Production

Pseudomonas syringae subsp. savastanoi causes tumors on olive and oleander by producing the plant growth regulators indoleacetic acid (IAA) and cytokinins following infection of the plant. The contribution of IAA production to the ability of P. syringae subsp. savastanoi to grow and survive in oleander leaf tissue was studied. Bacterial strains differing only with respect to IAA production were characterized. Growth and survival of wild-type and two mutant strains of P. syringae subsp. savastanoi in oleander leaf tissue were monitored by weekly colony counts and IAA plate assays. Growth rate of the three strains in culture and in planta did not differ significantly. However, the wild-type strain reached a higher population density and maintained its maximum density at least 9 weeks longer than either mutant population. An insertion mutant containing the IAA plasmid (pIAA), but incapable of IAA production, did not maintain a higher population density than a strain cured of the IAA plasmid. The pIAA-cured strain maintained a higher population density when coinoculated with an IAA-producing strain than when inoculated alone. These results suggest that IAA production may contribute to the fitness of P. syringae subsp. savastanoi in oleander tissue and that the iaa operon alone may be responsible for the competitive advantage of cells harboring pIAA.Key words: indoleacetic acid, bacterial ecology.

Bulb Development in Onion (Allium cepa L.) I. Effects of Plant Density and Sowing Date in Field Conditions

1986 ◽  
Vol 58 (2) ◽  
pp. 187-195 ◽  
Author(s):  
M. F. MONDAL ◽  
J. L. BREWSTER ◽  
G. E. L. MORRIS ◽  
HEATHER A. BUTLER
Keyword(s):  
Allium Cepa ◽  
Plant Density ◽  
Sowing Date ◽  
Field Conditions ◽  
Allium Cepa L

scholarly journals 031 Effects on the Supercooling Capacity of Capsicum annum L. by Epiphytic Bacteria Population

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 393C-393
Author(s):  
A. Rascon-Chu ◽  
A.A. Gardea ◽  
V. Guerrero-P ◽  
J. Martinez-T ◽  
C. Rivera ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Uv Light ◽  
Leaf Tissue ◽  
Epiphytic Bacteria ◽  
Vegetable Crops ◽  
Bacterial Strains ◽  
Temperature Exposure ◽  
Low Temperature Exposure ◽  
Ice Nucleation Activity

The effect of epiphytic bacteria population with different ice nucleation activity (INA) on the extent of supercooling of in vitro and leaf tissue disks of greenhouse-grown Capsicum annuum L. plants was determined. Bacterial strains were isolated on PDA and King's B medium from foliar samples of weeds from commercial apple orchards in Cuauhtemoc, Chihuahua, Mexico. Bacteria were screened by colony morphology, fluorescence under UV light, while growin on King's B medium plates and screened for ice-nucleating capability at -5 °C in suspensions of 108 cfu/mL. Ice nucleating (Ice+) and non-ice-nucleating (Ice-) active strains with fluorescent capacity were isolated from symptomless leaf samples. Four bacterial strains were used with different ina as epiphytic population models. Two Pseudomonas syringae strains, Pss29A and PD, from Oregon State Univ., with high Ice+ capability; P. fluorescens A-506, in its Blight Ban™ commercial lyophilized presentation; and UC001, a native fluorescent strain from CIAD-Cuauhtemoc; both Ice-strains. Freezing tests were carried out under controlled conditions. The high Ice+ strains Pss29A and PD increased the temperature of supercooling 2 and 1 °C compared to control samples. The non-inoculated tissue showed damage over 50% at -3 °C and below. Inoculated tissue with Ice+ strains (P. syringae 29A and PD), showed damage superior to 50% at -1 and -2 °C, respectively. Conversely, at none of the temperatures assayed, Ice-strains surpassed 50% damage. These results are of interest for further development of passive strategies towards minimizing damage due to low-temperature exposure of tropical vegetable crops.

scholarly journals On the effects of secretions of saprophytic bacteria on the course of mitosis in adventitious roots of Allium cepa L.

2015 ◽  
Vol 42 (1) ◽  
pp. 171-179
Author(s):  
Z. Kobierzyńska
Keyword(s):  
Allium Cepa ◽  
Chromosome Aberrations ◽  
Adventitious Roots ◽  
Bacterial Strains ◽  
Liquid Cultures ◽  
Allium Cepa L

The influence of 21 strains of saprophytic bacteria isolated from onion cultures on the course of mitosis and on the level of chromosome aberrations in adventitious roots of <i>Allium cepa</i> L. was studied. Liquid cultures of all bacterial strains caused no changes in divisions of the cells. However, ten of the strains were responsible for disturbances in this process. The nature of these disturbances depended to a large extent on the kind of medium in which the bacteria were grown.

scholarly journals Susceptibility of Twenty-Three Kiwifruit Cultivars to Pseudomonas syringae pv. actinidiae

2021 ◽  
Vol 9 (1) ◽  
pp. 33
Author(s):  
Thomas Thomidis ◽  
Dimitrios E. Goumas ◽  
Anastasios Zotos ◽  
Vassilios Triantafyllidis ◽  
Efthimios Kokotos
Keyword(s):  
Pseudomonas Syringae ◽  
Statistical Difference ◽  
Plant Disease ◽  
Control Plant ◽  
Field Conditions ◽  
Bacterial Strains ◽  
Resistant Cultivars

One of the best methods to control plant disease is the use of resistant cultivars. The purpose of this study is to evaluate 23 kiwifruit genotypes and cultivars for susceptibility to four strains of Psa (biovar 3) in alaboratory setting. The results showed that all the bacterial strains were pathogenic. There was no statistical difference among the bacterial strains tested. None of the kiwifruit cultivars tested were immune to Psa. There was a statistical difference in the level of susceptibility among cultivars. The cultivars Sorelli and D495/312 were the most susceptible, while the cultivar A501/44 was the most resistant. However, the above results must be verified in field conditions.

scholarly journals LIRIOMYZA TRIFOLII (BURGES) (DIPTERA: AGROMYZIDAE) UN NUEVO RECORD Y UN NUEVO REPORTE EN CEBOLLA, ALLIUM CEPA L., PARA PUERTO RICO

1969 ◽  
Vol 85 (1-2) ◽  
pp. 83-84
Author(s):  
Irma Cabrera-Asencio
Keyword(s):  
Puerto Rico ◽  
Allium Cepa ◽  
Liriomyza Trifolii ◽  
Allium Cepa L

LIRIOMYZA TRIFOLII (BURGES) (DIPTERA: AGROMYZIDAE) UN NUEVO RECORD Y UN NUEVO REPORTE EN CEBOLLA, ALLIUM CEPA L., PARA PUERTO RICO

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