三陟에서 새로 發見된 自生 蒙古桑 (Morus mongolica C.K.SCHNEIDER)의 主要特性

Agronomic characteristics of Morus mongolica C.K.SCHNEIDER newly discovered in samchok area, the middle eastern coastal region of Korea

Natural growing of Morus mongolica was newly discovered in Samchok area, the middle eastern coastal region of Korea. The southern limit of Morus mongolica distributed area in Korean peninsular was removed down to 37℃ 23’ north latitude by this finding. The main agronomic characteristics of Morus mongolica collected from Samchok area were as follows : The trained form after shoot-cut is open or inclined open type. Style and stigma length is about 1.2-1.4 and 2.0㎜, respectively. The number of chromosomes in a somatic cell is 28(2n=28). The sprouting stage of leaf is later than that of Morus bombysis by about five days and the cold-hardiness is very strong. High level of heterophylly is identified by the presence of several different forms of leaves in a plant : that is, medium to small-sized elliptical leaves, two-to-many-loabed leaves and pinnatisect leaves with deep lobations. Leaves are thick but water content is low. Dense, thin and long trichomes are distributed on the abaxial side of leaf. Aristates about 1.6~2.9㎜ in length are present at the edge of leaf. The plant showed no symptoms of dwarf disease and mulberry shoot gall midge damage. However, it suffered severely from the mulberry shoot die-back and bacterial blight.