Dissertation > Agricultural Sciences > Plant Protection > Phytosanitary > A variety of plant quarantine > Plant diseases,pest and weed quarantine

Application Study of Quarantine Method for Six Species of Lolium with Molecular Technology

Author ChenDongMei
Tutor JiangDaoSong;KangLin
School Hunan Agricultural University
Course Planting
Keywords Darnel is ITS sequences rDNA Detect
CLC S41-30
Type Master's thesis
Year 2007
Downloads 19
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Darnel are Gramineae darnel the genus ( ryegrass case ) , distributed in more than 140 countries and regions worldwide . Of the original non-toxic wheat, wheat detected , to carry incoming , imported food or introduction has been distributed to the country's 26 provinces , municipalities and autonomous regions imported from Bulgaria for the first time since 1954 . The darnel (including long awns darnel darnel Wada ) is important quarantine weeds in China and the world , and China since 1957 , has been classified as quarantine objects . Flax darnel hard darnel and Italian ryegrass is our highest interception rate from imported raw grain in three weed species , their seed appearance is very similar , non- professionals is difficult to identify to species . At home and abroad darnel quarantine and identification method mainly morphological , and morphological methods of identification requires a strong expertise and identification level , therefore to establish effective , accurate , practical and rapid means of detection and identification of molecular biology important. This article uses the molecular biology experimental method , darnel are six kinds of sample DNA is extracted using direct sequencing of PCR products were cloned and sequenced two methods , darnel are six kinds rDNA ITS region (including ITS -1 , 5.8 S rDNA and ITS-2) were sequenced . The results show that , darnel species : the total length of the ITS sequences of approximately 647 bp in ITS-1 length of 235 bp , 5.8S approximately 267 bp of ITS - 2 is about 145 bp in . The GC content of the ITS-1 region between 54.64% to 55.67% , the the 5.8S area GC content of 62.55% to 62.93% , 55.86% to 57.93% GC content of the ITS- 2 region . ITS -1 , 5.8 S rDNA and ITS-2 , respectively 16,7 and 7 variable sites . Variable sites , information sites 22 , eight specific recognition site , the difference was significant and stable , according to these sites completely darnel are six similar species to be identified . Phylogenetic tree with morphological classification using the neighbor-joining method to establish basic match , the darnel species classification and identification of important molecular biological detection and identification based on . The results showed that the rDNA ITS sequences characteristic can better reflect the darnel is intraspecific and interspecific differences in molecular markers for the identification of the genus darnel , for Port weeds quarantine economic , rapid and accurate identification of quarantine method.

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