Abstract

Cassava is a crop of significant economic importance. Thailand is the second largest global producer of cassava, with an annual export value above 100,000 million baht. Currently, Cassava mosaic disease is prevalent in 20 provinces across Thailand, indicating an epidemic. Consequently, farmers experienced significant losses in their agricultural yield. The objective of this study was to determine the distribution of resistance to Cassava Mosaic Disease in the progeny population of Hanatee and C33 varieties. The check varieties were C33, HNT, HB100, and B419. In the single row trial, the spacing between the rows is 1.2 meters and the spacing between the plants within a row is 1 meter. The disease severity was evaluated in score 1-5. Data was collected at two specific stages of cassava growth: when the plant was 4 months old and 8 months old. The experimental results revealed that there was the ratio of cassava mosaic disease resistance level 2:1:1 which were those having severity score 1, 2 and 3, respectively. This ratio supports the hypothesis of one cassava mosaic disease resistant locus from C33 variety and one cassava mosaic disease tolerant locus from Hanatee variety which are both heterozygous.