榆树是我县的乡土树种,以白榆为主,也有少量琅榆分布。白榆是我县四旁绿化的主要树种之一。为了培育出比当地白榆适应性强和生长快的榆树新品种,我们自一九七五年开始,在山东农学院的指导下,开展了榆树杂交育种,先后重复搞了二十五个杂交组合,获得杂交苗1296株,通过定植观察杂交后代差异较大,初步评选出白×春,白×灰两个生长表现良好的杂交后代,准备逐步推广应用。现介绍于下。 Elm is my native county species, mainly white elm, but also a small amount of Langyu distribution. White elm is one of the main tree species around the county green. In order to breed new varieties of elm that are more adaptable and grow faster than the local elm, we have conducted elm cross breeding under the guidance of Shandong Agricultural College since 1975, and have repeatedly conducted 25 hybrids 1296 hybrid seedlings were obtained. The hybrid progenies were observed by colonization, and the hybrid progenies of white × spring and white × gray were preliminarily selected for their potential application. Now introduced in the next.