RESULTS OF BREEDING TRIPLOID VH13 HYBRID VARIETY

VH13 hybrid mulberry variety was created by the Vietnam Sericulture Research Center, and it was approved as temporary variety for pilot production in some ecological regions by the Scientific council of Ministry of Agriculture and Rural Development in September 2000. Accordingly, it was approved as official national variety in April 2006, Because of using F1 heterosis and sexual propagation, VH13 hybrid mulberry has a lot of advantages such as: strong growth, high total branch length/tree (60.50m/ tree), short node (3.0-3.3cm), average duration for mature leaves, leaf productivity of 40 tons/ha/ year upwards (in stable mulberry field), increasing by 36% compared with Ha Bac variety, >60% compared with Bau Trang, Bau Den Bao Loc and China introduced ones. VH13 mulberry tree has less bloom, thick leaf, dark green, short node (3.0-3.2cm), good quality leaves. The protein content in its leaf is 22-24% while in Ha Bac and VH9 variety is 21.24% and 24.40%, respectively. The cocoon yield of silkworm which was fed by VH13 mulberry leaves is 10% higher than that of Ha Bac mulberry leaves and 19% higher than Chinese mulberry leaves. Shell ratio increases by more than 13%, with thicker cocoon shell, higher cocoon quality. 4th and 5th instars growth duration shortens one day. Mulberry consumption per one kg cocoon reduces by 16% compared to Ha Bac. Noted that VH13 mulberry variety generates many leaves in autumn, which is suitable for rearing high quality white cocoon silkworm. Advantages of VH13 mulberry variety in cultivation characteristics manifest easy leaf plucking, less branch scratch than Ha Bac and VH9, 30% higher harvesting yield than old varieties, VH13 has wide adaptability to different ecological regions, different soil types (river side land, coastal land, hill land and mountainous area), high multiplication coefficient: 300kg mulberry seed per 1 ha parental mulberry gardent/1 year, 28% lower material expenses for newly planting, all year round planting season, high planting survival above 90% and higher than planting by cutting. Especially, VH13 mulberry tree can grow quite better in drought region. VH13 disease ratio, disease index (which caused by some fungal species) are lower than Ha Bac and Chinese mulberry varieties. VH13 hybrid mulberry variety was approved as national variety by Ministry of Agriculture and Rural Development in April 2006 to be licensed to disseminate in production at the Northern and Central provinces.