Agriculture Reference
In-Depth Information
BRACT MOSAIC - BIOSECURITY THREAT
Cause
Banana bract mosaic virus
(Potyvirus).
Symptoms
The mosaic pattern on infected f flower bracts is obvious
and distinctive. Mosaic patterns, stripes and spindle-
shaped markings also occur on the pseudostem when
the outer layers are removed. These patterns can vary
in colour from chlorotic to reddish-brown, depending
on the banana cultivar. Leaf symptoms are not displayed
consistently, but are sometimes present as chlorotic
streaks and spindle shapes running parallel to the veins.
Source of infection and spread
Banana and the related abaca (
Musa textilis
) are the only
known natural hosts. The virus is spread by aphids,
including the banana aphid (
Pentalonia nigronervosa
), and
in infected planting material, including tissue culture.
Fig 5.63 Symptoms on a banana flower bract that is infected with
Banana bract mosaic virus.
Fig 5.64
Banana bract mosaic virus
showing a reddish-brown
mosaic pattern on the pseudostem after the outer leaf sheaf has
been removed.
Fig 5.62 Leaf symptoms of
Banana bract mosaic virus
.
