The resistance of some cassava lines/varieties to Sri Lanka cassava mosaic virus in Quang Binh province

Six lines or varieties of cassava, including three potential lines or varieties (HL-KM94, HL-S14, KM505-54) and three lines resistance to the Sri Lanka cassava mosaic virus (SLCMV) (HN1, HN5, and HN97), were evaluated in 2022 in Quang Binh province. The aim of this study was to select cassava lines/varieties with high yield, high starch content and resistance to SLCMV disease, suitable for local conditions. The experiment was designed in a randomized complete block design (RCBD), with 3 replications. The research results showed that the cassava lines/varieties used in the study had an average germination time of 16.7 - 22.0 days; the average height of the plant was 277.4 - 363.4 cm, and an average growth time of 277.4 - 363.4 cm and the average growth duration was from 272 - 300 days. The average tuber weight ranged from 190 - 850 g/tuber. The skin color of the tuber was from white to light - yellow and the tuber flesh was white (except HN97 which had yellow tuber flesh). Regarding SLCMV, the study showed that 3 cassava lines including HN1, HN5, and HN97 did not show any signs of SLCMV disease at the seedling stage and after 6 months planting, the SLCMV disease appeared at a low average rate of 3.1 - 5.2%. Based on these results, two cassava lines/varieties HN1 and HL-KM94 were selected for their good growth, resistance to SLCMV, and high fresh tuber yield of 48.0 - 54.9 tons/ha. Their harvest index ranged from 64.4 - 67% and they had starch content over 28%.