scholarly journals Transmission of the Stubborn Pathogen in Citrus by Leaf-Piece Grafts

1972 ◽  
Vol 5 (5) ◽  
Author(s):  
E. C. Calavan ◽  
Edward O. Olson ◽  
D. W. Christianson
Keyword(s):  
Leaf Piece

Evaluation of Treatments for Elimination of Foodborne Pathogens on the Surface of Leaves and Roots of Lettuce (Lactuca sativa L.)

2009 ◽  
Vol 72 (2) ◽  
pp. 228-234 ◽  
Author(s):  
GUODONG ZHANG ◽  
LI MA ◽  
LARRY R. BEUCHAT ◽  
MARILYN C. ERICKSON ◽  
VANESSA H. PHELAN ◽  
...  
Keyword(s):  
Lactuca Sativa ◽  
Foodborne Pathogens ◽  
Fluorescent Protein ◽  
Enrichment Culture ◽  
Factors Affecting ◽  
Surface Disinfection ◽  
E Coli ◽  
Leaf Piece ◽  
Lactuca Sativa L ◽  
Leaves And Roots

Several outbreaks of Salmonella and Escherichia coli O157:H7 infections have been associated with consumption of leafy greens. Questions remain concerning the ability of these pathogens to become internalized within lettuce and spinach tissues. An effective validated surface disinfection method for lettuce is needed before factors affecting internalization of pathogens can be studied. The objective of this study was to develop a surface disinfection method for lettuce leaves and roots. Iceberg lettuce (Lactuca sativa L.) leaves cut into pieces (3 by 3 cm) and lettuce roots were inoculated by immersing in suspensions of five-strain mixtures of green fluorescent protein–labeled E. coli O157:H7, Salmonella, or Listeria monocytogenes at populations of 7 to 8 log CFU/ml for 10 min at 20 ± 1°C. Inoculated samples were placed in a laminar flow biosafety cabinet for 30 min before treating with disinfectants. Thirteen surface disinfection methods were compared for their efficacy in killing E. coli O157:H7 on lettuce leaf and root surfaces. E. coli O157:H7 initially at 5.8 or 6.8 log CFU/leaf piece or root was not detected by enumeration (<0.6 log CFU per leaf piece) on samples treated for 20 min with 10,000 μg/ml sodium hypochlorite (NaHClO) or in solutions containing ethanol and mercuric chloride (HgCl2). With all other methods, E. coli O157:H7 populations ranged from 2.8 to 4.4 CFU per leaf piece or root after treatment. Trends in leaf and root print and enrichment culture results were consistent with enumeration results. Dipping in 80% ethanol for 10 s followed by immersion in 0.1% HgCl2 for 10 min was determined to be the most effective surface disinfection method for inactivating E. coli O157:H7 on lettuce leaves and roots and was also validated for inactivating Salmonella and L. monocytogenes.

scholarly journals Effects of BA and Leaf Piece Orientation on Adventitious Bud Formation in Leaf Cutting of Begonia Tuberhybrida Group

2007 ◽  
Vol 76 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Yukiko Shimada ◽  
Genjiro Mori ◽  
Masayuki Oda ◽  
Genjiro Ishida
Keyword(s):  
Adventitious Bud ◽  
Bud Formation ◽  
Leaf Piece ◽  
Adventitious Bud Formation ◽  
Leaf Cutting

scholarly journals Identificación molecular morfológica de las especies de Fusarium spp., asociadas al cultivo de pimienta negra (Piper nigrum) en Sarapiquí y Guatuso en Costa Rica

2020 ◽  
Author(s):  
Gabriela Chinchilla Salazar ◽  
Mónica Blanco Meneses ◽  
Óscar Castro Zúñiga
Keyword(s):  
Costa Rica ◽  
Fusarium Oxysporum ◽  
Fusarium Solani ◽  
Fusarium Proliferatum ◽  
Piper Nigrum ◽  
Fusarium Spp ◽  
Leaf Piece ◽  
El Sistema

Introducción. La pimienta es una especie de la familia de la Piperaceae, originaria de la Costa de Malabar, situada en Kerala al sur de la India. En Costa Rica, las principales plantaciones de pimienta se localizan desde Upala hasta Talamanca, e incluye toda la franja costera y la parte baja de Sarapiquí. Según estudios de factibilidad, el país cuenta con el potencial para producir pimienta con altos parámetros de calidad. Sin embargo, las enfermedades vasculares son una de las principales limitantes del cultivo.Objetivo. El objetivo de esta investigación fue el aislamiento e identificación molecular y morfológica de las especies de Fusarium asociadas al cultivo de la pimienta (Piper nigrum L.) en2 de las principales zonas productoras del país. Materiales y métodos. Se recolectaron treinta muestras de plantas enfermas de distintas fincas en las zonas de Sarapiquí y Guatuso, se describieron detalladamente los síntomas observados en el sistema radical y/o la base del tallo para  cada una de las plantas recolectadas. Los veintiún aislamientos de Fusarium spp. obtenidos se identificaron molecularmente con la secuenciaparcial del gen Factor de Elongación 1α (EF-1α)y para la identificación morfológica se utilizaron los medios de cultivo PDA y Carnation Leaf-piece Agar (CLA). Resultados y conclusiones. Se confirmó la presencia de Fusarium oxysporum en las muestras provenientes de Sarapiquí, así como la presencia de Fusarium solani en ambas zonas muestreadas. Se reporta por primera vez, la presencia de las especies Fusarium concentricum y Fusarium proliferatum asociadas a la marchitez vascular.

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