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Recently,three different BBTV-DNA components had been cloned
and sequenced. The three cloned BBTV-DNA components
labeled with biotin were used as DNA probes (Probe C-1, Probe
C-2, and Probe C-3) for disease diagnosis. Four pair of
oligonucleotides (c-1a/a-1b,c-2a/c-2b,c-3a/c-3b,and s6a/s6b)
sythesized according to their sequences,were used as primer
pairs in polymerase chain reactions(PCR).Using these BBTV-
specific DNA probes in dot hybri dizations,positive results
were observed with 30 ∼ 8pg of purified BBTV-DNA
extracted from severe strain, and 60 ∼ 15pg from mild
strain, except component 1. Cross dot hybridization among
BBTV-DNA components showed that distinct cross hybridiza- tion
between C-2 and C-3 components,slight dot signal between C-1
and C-1 or C-3,while C-s6 did not show dot signal in
corssing with the other 3 components. The detectable end-
points of DNA extracted as template in PCR test were
found to be 1pg using c-1a/c-1b,1/10pg with c-2a/c-2b, and
1/1000pg with in c-3a/c-3b primer pairs. A simple and rapid
method was developed for prepa- ring total DNA from BBTV-
infected plants, and was applied to detection and analysis
of BBTV-DNA components in different strains, tissues and
vector aphids.
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