Orchids

Detection, Characterization, and
Management of Pineapple
Mealybug Wilt-Associated Viruses
John Hu
University of Hawaii
Pineapple
in Hawaii
Hawaii’s number one
agricultural
commodity
Hawaii Agricultural Statistics Service (2002)
Symptoms of MWP
• Reddening of the leaves
• Downward curling of the
leaf margins
• Loss of turgidity, leaves
reflex downwards
• Leaf tip dieback
• Plants either recover or
endure further leaf tip
dieback resulting in death
Healthy
MWP
Association of Mealybugs

● Pre-plant dip (mealybugs)
● Overhead application (mealybugs)
Potential Problems
• Amdro®
– Inactivated by moisture
– Not effective against some ant
species such as Technomyrmex
albipes
• Diazinon
– Use in pre-planting dips has been
eliminated
Research Areas
• Detection
• Epidemiology
• Etiology
• Management
Detection Assays
1. dsRNA analyses
2. EM & ISEM
3. ELISA
4. Tissue blot Immunoassay*
5. RT-PCR*
Multiple Closteroviruses
in Pineapple?
200nm
• ISEM revealed that not all
virus particles were being
decorated by monoclonal
antibodies
• At least two serotypes exist

gel electrophoresis
• May represent the
replicative forms of two
viruses with different
genome sizes
Lane 1 - dsRNAs extracted from 100 g of TBIA-positive pineapple tissue
2 - dsRNAs extracted from 5 g of citrus bark infected with Citrus tristeza virus
Multiple Closteroviruses
in Pineapple?
hsp70h
Clone
nt
Homology
• Initial cloning and
sequencing revealed two
distinct hsp70h genotypes
in viral dsRNA
• PMWaV-1
• PMWaV-2
pC15
100%
pC16
100%
pC18
47%
pC12
PMWaV-2 Monoclonal Antibody Selection
PMWaV
2
1 and 2