Dreaded Virus!

[Rogan]

I recently had to throw two pots of Lachenalia viridiflora away. After four years of culture from seed, the leaves emerged contorted with white streaks and spots with a pronounced bronze / purple flush - classic symptoms of a virus infection I would say.

My question is: in your experience, can virus infections be transmitted through the seed? I am neurotic about virus and, to lessen the chances of infection, grow most of my bulbs from seed. I have many other plants in my collection, including diverse Lachenalia species, which show absolutely no sign of infection.

I am shattered and mystified as how can two pots of healthy seed-grown plants suddenly show symptoms of a virus when none of the others around it do?         

[Giles]

Yes they can.
Pollen too.

[Lesley Cox]

Did you take pics of the infected bulbs Rogan? Maybe we need to start a database thread of virus pictures and the plants they attack. I'm wondering if we are getting paranoid about the virus possibility but perhaps not, and if it really IS such a problem, we should be identifying as many as possible and working out how to cope.

[Lesley Cox]

Yes they can.
Pollen too.

Oh hell!

[iann]

Some viruses can be transmitted through seed, but some aren't.  Insects are another vector when a virus can't make its own way through a plant population.

[Maggi Young]

Re-opening this thread to post a link to this open access paper published by The American Phytopathological Society. (Editor-in-Chief: Mark L. Gleason)

May 2012, Volume 96, Number 5

Viruses that Enhance the Aesthetics of Some Ornamental Plants: Beauty or Beast?
Rodrigo A. Valverde, Louisiana State University Agricultural Center, Baton Rouge, LA 70803;
Sead Sabanadzovic, Mississippi State University, Mississippi State, MS 39762;
and John Hammond, Floral and Nursery Plants Research Unit, USDA-ARS, U.S. National Arboretum, Beltsville, MD 20705

Open Access.

Abstract:
Microbes including fungi, bacteria, and viruses commonly cause diseases in humans, animals, and plants. Nevertheless, there are many beneficial microbes. Recently, researchers proved that a phytoplasma is the biological agent causing free-branching in poinsettias which is an economically beneficial trait for their producers. Beneficial viruses for plants have been discovered as well. Symptoms due to virus infections include foliar mosaic, mottle, ring spots, necrosis, malformation, curling/rolling, yellow vein, flower and/or foliage variegation, fruit malformations, and overall plant stunting. However, interactions between plant viruses and their hosts do not always result in disease. There are other viruses that can cause desirable effects in their hosts, and infected plants have been selected or in some cases used by ornamental horticulturists to enhance their aesthetics. Plants with unusual foliage and/or flowers are highly sought by horticulturists and many ornamental plant enthusiasts. Selections of many ornamental plants exhibiting green leaves with other colors such as white, yellow, or red, alone or combined (generally known as variegations) have been propagated and commercialized as distinct cultivars. Similarly, this practice has been conducted with flowers exhibiting desirable aesthetic value, usually in the form of flower breaking (flowers in which petals are variegated due to the irregular distribution of pigment). Plant viruses can cause symptoms that mimic genetic variegations and vein discolorations. In this paper, we discuss some viruses that enhance natural beauty of certain ornamentals and increase their commercial value, and we discuss potential drawbacks and repercussions associated with their use.
http://apsjournals.apsnet.org/doi/pdfplus/10.1094/PDIS-11-11-0928-FE

[Maggi Young]

2009 article by Deborah Mathews of UC Rivierside

'Optimizing detection and management of virus diseases of plants'
http://ucanr.org/sites/ucnfa/files/62197.pdf