An Australian study revealed that Indian subcontinent is a major hub of the long-distance Banana bunchy top disease (BBTD) movements.
Dr. Arvind Varsani from the University of Canterbury led this study about the evolution and distribution of a major banana disease virus, with funding from the Masrden Fund of New Zealand. They wanted to know whether humans inadvertently spread the virus through moving banana plants around the planet for horticulture.
Researchers discovered that the virus jumped from the Indian subcontinent to Africa twice: "firstly to sub-Saharan Africa between 1825 and 1934, and secondly to Egypt between 1929 and 1936." Too, it moved into the Pacific region twice, to Tonga between 1735 and 1882 and to Australia between 1943 and 1974.
These results clearly show that the virus was gradually moved from one place to another through infrequent dispersal events over the past 1,000 years, proving human movements across the globe have nothing to do with the wide spread.
Banana aphids transmit the virus to new host plants as they feed. This is the primary reason as to why the disease could quickly spread across banana plantation.
"Once a plant is infected there is no cure," Australian Food News reported. "It must be dug out and burnt to prevent further disease spread, resulting in significant long term loss to the farmer."
All progenies of an infected plant will also be infected with the virus since banana plants are propagated by cultivating shoots from the base of a parent plant.
Plants infected with Banana bunchy top disease suffer major total crop losses most of the time. The disease was not identified until 1990s, more than a millennium since its first case in Fiji in South East Asia.
The 4th most important food crop in the world were thought to have originated in Southeast Asia between 7000 - 10,000 years ago. By 3000 years ago, banana plants have already reached as far as West Africa. These fruits have been moved around the globe frequently by humans over the past 10,000 years with countless introductions and re-introductions into motherlands in present times.
