Various bacterial species are known to be agents causing soft rot of potatoes. The results of this study showed that potato soft rot is widely spread in different potato planting areas in Jordan. A survey was conducte...Various bacterial species are known to be agents causing soft rot of potatoes. The results of this study showed that potato soft rot is widely spread in different potato planting areas in Jordan. A survey was conducted through the years 2013-2015 to detect potato soft rot disease in Jordan, two hundred and four rotted potato samples were collected from different potato growing areas through different potato growing seasons. One hundred and thirty one bacterial isolates were isolated, purified on selective media and identified as Pectobacterium carotovorum subspecies carotovorum (Pcc) by different biochemical and physiological tests. Furthermore, 131 Pcc Jordanian (Jo) isolates were identified by PCR analysis of total DNA extracted from isolates that were biochemically identified as Pcc using universal primer Fd1/Rd1. Cloning and sequencing of representative PCR products, amplifying the 16S rDNA region were done. Phylogenetic analysis of the Pcc Jo-isolates revealed other than 90% similarity with different reference Pcc strains available at the GenBank. Different rot causal agents also were detected by PCR amplification and further sequences. The sequencing data revealed similarities to Pseudomonas fluorescence, Enterobacteriaceae genera such as Enterobacter spp., Serratia spp. and Klebsiella spp., in addition to Pectobacterium carotovorum subsp. carotovorum. This study indicated that using molecular techniques such as amplification of 16S rDNA region is a sensitive and specific method for detecting Pcc as potato soft rot causal agent. So far this is the first study where Pcc has been identified by using PCR and sequencing approaches in Jordan.展开更多
The morphological characteristics, pathogenicity and biological characteristics of the pathogen isolated from Maryland tobacco in Wufeng County of Hubei Province were studied in the laboratory. After cultivation on LB...The morphological characteristics, pathogenicity and biological characteristics of the pathogen isolated from Maryland tobacco in Wufeng County of Hubei Province were studied in the laboratory. After cultivation on LB medium at 28℃ for48 h, the colonies were light yellow, circular or amorphous, translucent, with smooth and slightly concaved surface and neat edge. Observation under electron microscope showed that the isolates was red-shaped, decapsulated and gram-nega- tive in the size of （0.5 - 1.0） μm × （2.2 -3.0） μm, with 2 -8 flagella. After cultivation on CVP medium at 28 ℃ for 48 h, the colonies were sunken like a cup. The pathogen was able to grow in 5% NaCl medium at 37 ℃, and produced acid through glucose fermentation; it was facuhative anaerobic, and could use citrates, but could not produce indole. It was preliminarily confirmed that the pathogen causing Wufeng Maryland tobacco hollow stalk was Pectobacterium carotovorum subsp. carotovorum.展开更多
文摘Various bacterial species are known to be agents causing soft rot of potatoes. The results of this study showed that potato soft rot is widely spread in different potato planting areas in Jordan. A survey was conducted through the years 2013-2015 to detect potato soft rot disease in Jordan, two hundred and four rotted potato samples were collected from different potato growing areas through different potato growing seasons. One hundred and thirty one bacterial isolates were isolated, purified on selective media and identified as Pectobacterium carotovorum subspecies carotovorum (Pcc) by different biochemical and physiological tests. Furthermore, 131 Pcc Jordanian (Jo) isolates were identified by PCR analysis of total DNA extracted from isolates that were biochemically identified as Pcc using universal primer Fd1/Rd1. Cloning and sequencing of representative PCR products, amplifying the 16S rDNA region were done. Phylogenetic analysis of the Pcc Jo-isolates revealed other than 90% similarity with different reference Pcc strains available at the GenBank. Different rot causal agents also were detected by PCR amplification and further sequences. The sequencing data revealed similarities to Pseudomonas fluorescence, Enterobacteriaceae genera such as Enterobacter spp., Serratia spp. and Klebsiella spp., in addition to Pectobacterium carotovorum subsp. carotovorum. This study indicated that using molecular techniques such as amplification of 16S rDNA region is a sensitive and specific method for detecting Pcc as potato soft rot causal agent. So far this is the first study where Pcc has been identified by using PCR and sequencing approaches in Jordan.
基金Supported by Tobacco Research Project of Hubei Tobacco Company(2011-13)Scientific and Technological Project of Yichang City(A2011-201)
文摘The morphological characteristics, pathogenicity and biological characteristics of the pathogen isolated from Maryland tobacco in Wufeng County of Hubei Province were studied in the laboratory. After cultivation on LB medium at 28℃ for48 h, the colonies were light yellow, circular or amorphous, translucent, with smooth and slightly concaved surface and neat edge. Observation under electron microscope showed that the isolates was red-shaped, decapsulated and gram-nega- tive in the size of （0.5 - 1.0） μm × （2.2 -3.0） μm, with 2 -8 flagella. After cultivation on CVP medium at 28 ℃ for 48 h, the colonies were sunken like a cup. The pathogen was able to grow in 5% NaCl medium at 37 ℃, and produced acid through glucose fermentation; it was facuhative anaerobic, and could use citrates, but could not produce indole. It was preliminarily confirmed that the pathogen causing Wufeng Maryland tobacco hollow stalk was Pectobacterium carotovorum subsp. carotovorum.
