Biotech experts working to develop virus-resistant abaca

MANILA, Philippines - The Department of Agriculture-Biotechnology Program Office is seeking to rehabilitate the abaca industry in the Bicol region by developing better strains of the plant that are resistant to the deadly mosaic, bract mosaic and the bunchy-top viruses that crippled the country’s biggest abaca producer in 1999. Director Alicia Ilaga of the DA-BPO said while Bicol accounts for 66 percent or 52,666 hectares of the total abaca area mapped by the department, it also reported a 27 percent incidence of viral diseases, particularly bunchy top. To answer the demand by its clients, abaca producers in Bicol have to buy the fiber from Eastern Visayas. At the same time, Ilaga reported that DA biotechnologists were concerned about the pest (Tagarino et al 2004), making the abaca industry in the region dependent on Eastern Visayas to meet export demand. For the past three centuries, she said, abaca production have negative growths of 0.15 percent, 0.84 percent and 0.12 percent, respectively, meaning the industry must be reinvigorated to respond to increased demand in the global market. Ilaga said the University of the Philippines Los Baños College of Agriculture, UPLB Crop Science Cluster-Institute of Plant Breeding, FIDA and the DA-BPO are now collaborating to counter the deleterious impact of the deadly pests that attack abaca. Thus far, the team has been working to develop varieties that are resistant to the bunchy-top, mosaic, and bract mosaic viruses through radiation-induced mutation. Dr. Teodora O. Dizon of the CSC-IPB in UPLB and her team worked on two commercial varieties of abaca. These are the Tinawagang Pula and Tangongon from Sorsogon. Dizon’s team tried to determine the lethal dose for the abaca varieties and irradiate shoot cultures to find out the correct dosage to make these varieties resistant to the viruses. Suckers were collected from the two varieties and were analyzed for the presence of viruses, with infected plants eventually being. Tissue cultures of the Tinawang Pula variety from Albay were also obtained. Both cultivars were successfully micropropagated through in vitro culture and system regeneration and the rest were subjected to the process of trial and error in determining the right lethal dose to attain the plants’ immunity. Dr. Antonio Lalusin Jr. of the CSC-IPB in UPLB, also a member of the first abaca project, worked on the development of molecular markers in abaca to eliminate only one abaca virus, the bunchy top. The bunchy top virus is the most deleterious among the three viruses. It does not only destroy the fiber quality of abaca plants. Once the virus hits, plant growth ceases, therefore, the retrieval of fibers from the infected plants would be impossible. Lalusin’s team utilized the bunchy-top resistant genes of Pakol, a variety of banana, by cross breeding them with abaca plants and later on breeding them back to the pure-bred abaca plants. Tests for resistance to bunchy-top were later conducted by infecting the plants with the virus. The project aims to come up with bunchy-top resistant abaca plants that yield more fiber of good quality. - GMANews.TV