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据1984年的统计,日本已经建成柳杉种子园537公顷,其种子产量也与年俱增,但仍不能充分满足生产上对种子的需求,而且多年来的实践表明,这种普通型种子园也存在着几个极需解决的问题:1.在建园后要有近十年的时间才能大量稳定地生产种子;2.这种种子园要占居大面积的优良土地;3.很难根据子代测定结果对种子园内现有的无性系进行更换,而只能长期固定利用;4.难以施行人工促进开花结
According to the statistics of 1984, Japan has built 537 hectares of Cryptomeria Seneca and its seed production has also increased with each passing year, but it still can not fully meet the demand for seeds in production. Practice over the years shows that this common type of seed orchard There are also several problems to be solved: 1. There is almost a decade after the establishment of the park to produce seeds in large quantities in a stable manner; 2. This seed orchard needs to occupy a large area of good land; 3. It is difficult According to the results of the offspring of the seed in the existing clonal exchange, but only long-term fixed use; 4. Difficult to implement the artificial knot