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几年来,由山东、河南、天津、河北、宁夏、新疆等十三省市区组成的全国榆树协作组根据“以选为主,选、育、引相结合”的方针,积极开展了白榆良种选育工作。取得了初步成效。 为了进一步研究白榆在自然生境内的变异类型,探讨主要形态变异与经济性状的相关程度,统一各地白榆形态型的划分标准,为白榆良种选育工作提供科学依据,在中国林科院林研所指导下,全国白榆协作组组成了由山东、河南、天津、河北、宁夏五省、市、区参加的白榆自然类型调查组,在北纬34°——41°,东经114°——119°范围内进行了调查研究。历时三个月,比较细致地分析了平原、山区、盐碱地等不同生境中白榆形态变异,统一划分出自然类型,并通过经济性状对比,评选出优良类型。现将有关材料摘录介绍于后。
In recent years, the national elm group composed of 13 provinces and municipalities in Shandong, Henan, Tianjin, Hebei, Ningxia, Xinjiang and other provinces and autonomous regions actively carried out the development of elm in accordance with the principle of “combining election, election, education and guidance” Breeding breeding. Achieved initial results. In order to further study the variation types of Ulmus pumila in natural habitats, explore the correlation between major morphological variations and economic traits, unify the classification standard of Ulmus pumila morphogensis, and provide scientific basis for the breeding of Ulmus pumila seeds, Under the guidance of the Institute of Forestry, the national white elm collaborative group formed a natural type survey team of Elm Ulmus from five provinces, cities and districts in Shandong, Henan, Tianjin, Hebei and Ningxia. The investigation was conducted at 34 ° - 41 ° North latitude and 114 ° E - 119 ° range conducted a survey. After three months, the morphological variations of Ulmus pumila in different habitats such as plains, mountains, saline-alkali land and so on were analyzed in more detail. The natural types were divided uniformly and the good types were selected through the comparison of economic traits. Now extract the relevant materials introduced later.