Originally Posted by venturabananas
It is my understanding that stressful conditions can cause bananas with BSV to exhibit the symptoms of the virus, whereas under optimal conditions, they may exhibit few or no symptoms. Tony's plants exhibited fewer symptoms than mine. Goes to show who treats their bananas better!
For clarification, I am pretty sure that there are non-integrated forms of BSV. In these cases, the viral DNA has not been inserted into the banana DNA. The non-integrated form can be spread my mealybugs (just like aphids can spread the BBT virus). But integrated forms of BSV can't be spread. I think that's the deal.
There are different species, but they all pretty much act the same. The virus itself is not in the banana DNA, just the nucleotide sequence which is the instructions on how to make the virus, the banana creates the virus from it's own protein synthesis mechanisms. Once the virus is created in the plant, it does not matter the form, it can spread to other plants by the mealybugs.
The species in Mysore is Banana steak Mysore virus. Other identified species include Banana streak Goldfinger virus, and Banana steak Obino l'Ewai virus. They just refer to on which cultivars they were first identified. BSV is associated with M. balbisiana genomes, but there are also other similar viruses in all M. acuminata. It is just a matter of whether or not those sequences are expressed to create the virus. Once the virus is created, it is active. There are many cases of these virus sequences integrated into plants, but only very few cases, as in banana, where it is infectious and causes disease. There are still many unknowns about the virus because it is a rather rare situation.