落叶松杂种优势的动态分析和利用途径

经过20多年观测得知，以日本落叶松为亲本分别与长白落叶松、兴安落叶松、欧洲落叶松、华北落叶松杂交都有杂种生长优势，且苗期、早期（10年生幼树）优势表现明显；杂种生长优势是变动的，随着林龄增长杂种优势逐渐缓慢递减；部分杂种组合在16～21年生时，其生长低于母本日本落叶松，但仍然高于父本长白、兴安、欧洲、华北落叶松。杂种优势的高低、延续时间的长短与亲本选用、组合搭配、杂种生长节律及立地环境都有关系，且一般母本作用大；准确选用亲本，杂交效果会更好；利用杂种生长优势的最好形式是建立杂交种子园，杂交种子园杂种出现率的高低取决于两个亲本雌雄花期的同步程度；选择无亲缘关系的杂种第一代优树通过嫁接建立杂种落叶松种子园是生产大量优良杂种的好形式。

The Dynamic and Advantage Utilization of Larch Heterosis

The growth advantage of interspecific hybridization combination and single combination hybrid was test through over 20 years. The hybridization combination of Japanese larch as parent has heterosis and the heterosis was obvious in seedling stage and early birth of sapling （ 10 ）. Growth advantage decreased slowly along with the forest age. The combination of hybrid larch of 16 -21 years is lower than the female parent Japan, but still higher than male in changbai, utilize modern, European, and north China larch. The Heterosis and the length of duration was up to parent selection, combination collocation, hybrid growth rhythm and site environment, the female parent was so important that the parent was select accurately and the hybrid effect would be better, the best form Using hybrid growth advantage is to build hybrid seed orchard, the rate of hybrids depends on the flowering synchronization of the parents. The hybrid seed orchard was built by grafting the first filial generation champion tree which would produce a large number of excellent hybrid.