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(一)杨树选育的标准。抗寒力在我区杨树造种中应占重要的地位。已往杨树品种选育,只强调速生这个指标,对品种的抗寒力突出不够,这个问题到目前为止不能说已经解决了,它是北疆地区杨树选种几经周折的主要原因。往往一个地区受低温造成严重损失,另一地区却因暂时未出现低温,放弃对这个抗寒指标的重视,强调本地区气候条件特殊性,没能认识到低温在北疆地区不同年份循环出现的特点。更没有将冻害和寒
(A) poplar breeding standards. Cold hardiness in my area of poplar seed production should occupy an important position. Poplar breeding has been to the past, only emphasizes the indicator of fast-growing, outstanding varieties of cold stress is not enough, so far we can not say that this issue has been resolved, it is the northern part of the main reasons for the selection of poplar after several twists and turns. Often a region caused by severe damage caused by low temperatures, another region because of the temporary absence of low temperature, give up the importance of this cold indicator, emphasizing the particularity of climatic conditions in the region, failed to recognize the cold in different years in northern Xinjiang cycle Features. More will not freeze and cold