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油松在我国分布很广,是北方广大地区的主要造林树种之一。因此,对油松进行选择育种是很重要的。由于油松分布广,故变异较多,为了从中选出速生优良类型,我们从1972年起对油松不同子叶数的苗木及不同类型进行了栽培试验。现将试验情况与结果报告如下。材料1972年我们在进行油松产地试验育苗时,发现每一产地中都有子叶数不相同的苗木存在。为了阐明子叶数不同是否对树木的生长会发生影响,我们便从不同产地中按子叶数不同挑选出一定株数的苗木,即按6—12子叶的等级对苗木进行了挑选,并于1973年将同一子叶
Pinus tabulaeformis is widely distributed in our country and is one of the main afforestation species in the vast northern areas. Therefore, the selective breeding of Pinus tabulaeformis is very important. Because of the wide distribution of Pinus tabulaeformis, it has many variations. In order to select the best types of fast-growing ones, we planted the seedlings and different types of Pinus tabulaeformis seedlings from 1972 onwards. Now the test results and the results reported below. Material In 1972, when we conducted seedling trial in Chinese pine, we found that there were seedlings with different numbers of cotyledons in each producing area. In order to clarify whether the different number of cotyledons will affect the growth of trees, we pick out a certain number of seedlings according to different cotyledon numbers in different habitats, that is, select the seedlings according to the grade of 6-12 cotyledons and select the seedlings in 1973 The same cotyledons