Abstract

Cassava mosaic disease is very problem of Thailand. Currently, there are no cultivars that be able to resist to cassava mosaic disease and it is still in breeding process. This experiment derived inbred from Kasetsart 50 and Rayong1. The purpose of this experiment was to evaluate the resistance of cassava mosaic disease in inbred lines of Kasetsart 50 and Rayong 1 varieties. Using randomized completely block design (RCBD) 3 Replications. Evaluated in 1 to 6 months after planting by scoring (score 5 level: 1, 2, 3, 4 and 5 ) and calculate the disease index. Then the harvesting was at 10 months after planting. Fresh root yield and starch content of each line were weighed and compared. The results showed that DS59-21-3 and DS59-21-2 which was an inbred of Kasetsart 50 and S55-17-39 which was an inbred of Rayong 1. They were suitable for utilizing as tolerance inbreds because they could provide high production and high tolerant to cassava mosaic disease.