英语语法分析

Mulberry bacterial disease is one of the main diseases. It occurred widely and influenced the sericultural production great- ly.

桑疫病是桑树的主要病害之一，各地发生普遍，对蚕桑生产的影响很大。

Mulberry bacterial disease is the major and serious disease that does harm to the twigs and leaves of mulberry, and is widespread in sericultural areas.

桑细菌性疫病是危害桑树幼枝、叶的一种主要病害，在我国蚕区普遍发生且危害较严重。

The new mulberry varieties bred by The Sericultural Research Institute of Shandong, which originated from the endemic mulberry varieties of Shandong, inherit the good points of the parent.

山东省蚕业研究所育成的新品种（系），应用山东地方品种作为亲本，承袭了山东地方品种的优点。