Biology Reference
In-Depth Information
Chrysanthemum Mosaic,
Chrysanthemum B Carlavirus
Cineraria Mosaic
Mottling, dwarfing, and distortion of leaves,
transmitted by seed, mechanically, and by
Aphis
marutae
.
Noordam's B, Keller's Q, and other virus strains
are widespread in chrysanthemum with mild to
severe leaf mottling and sometimes a brown
streaking of flowers. Transmission is by grafting
and by aphids. Control by indexing tips from
heat-treated plants on reliable test varieties to
make sure they are virus-free.
Citrus Enation - Woody Gall
Luteovirus
Found in different species of Citrus, Ulmus,
Morus, Rosa, Prunus, Viburnum and Ecualyptus.
Chrysanthemum Ring Spot
Citrus Exocortis Viroid
Reported from Alabama in plants also
afflicted with Stunt. Large yellowish chlorotic
ring
patterns,
severe
leaf
dwarfing
and
Probably same as Rangpur lime disease; in Florida
and Texas on red grapefruit and sweet orange
trees, on Rangpur lime and trifoliate orange root-
stocks. Trees are stunted with bark shelling.
distortion.
Chrysanthemum Rosette
Citrus Leaf Rugose Ilarvirus and Citrus
Variegation Ilarvirus
A strain from symptomless Ivory Seagull pro-
duces veinbanding, crinkle, distortion, rosetting
on Blazing Gold.
Disease known as citrus psorosis virus complex.
Viruses spread in California and caused psorosis
of young leaves and malformation of the old
ones.
Chrysanthemum Stunt Viroid
Widespread in greenhouses and gardens. Symp-
toms vary with variety, but plants are dwarfed,
with small flowers and leaves and bloom earlier
than normal or later in some varieties. Blazing
Gold, Blanche, Mistletoe,Daunle ,and
Bonnie Jean often used as indicator varieties.
Leaves of Blanche are crinkled, and Mistletoe
has a “measles” pattern. Transmitted by dodder,
sap-inoculation, grafting with incubation period
6 weeks or longer; no insect vector is known.
Many plant species have been infected experi-
mentally. Commercial growers go to great
lengths to select and reselect a virus-free
stock, and great care is taken to prevent
recontamination. Garden varieties are now
indexed and available.
Citrus Leprosis Rhabdovirus
Transmitted
by mite-vector
Brevipalpus
phoenicis
.
Citrus Psorosis Complex: Citrus Leaf
Rugose Ilarvirus, Citrus Ringspot
Virus, Citrus Variegation Ilarvirus
Found wherever citrus is grown. Leaf symptoms
are small elongated white or yellow areas near
veins. Bark symptoms are scales or small pus-
tules with irregular growth and gum deposits.
With B strain of the virus, leaves have dots,
