桉树杂交育种的研究

Cross Breeding in Eucalyptus

以尾叶桉为母本，细叶桉、赤桉、窿缘桉、柳桉、巨桉、雷林一号桉、巨桉×尾叶桉和粗皮桉为父本，进行了２０１个组合的人工控制授粉，已掌握各亲本树种的开花物候。改进花粉处理和贮藏以及人工授粉技术，经干燥处理的花粉，在低温（－１８～２２℃）下贮藏４２个月，发芽率保持在６０％以上。建有７２个杂种桉参试的试验林７块。３年生杂种桉的材积生长大部分具有明显的杂种优势，配合力强的尾叶桉×细叶桉和尾叶桉×赤桉，单株材积的实际增益分别为１２０．７３％和８９．４０％。

Two hundred and four hybrids have been produced with controlled pollination method since 1989, of which the mother tree is Eucalyptus urophylla and the fathers are E. tereticornis, E. camaldulensis, E. exserta, E. saligna, E. grandis, E. leizhou No. 1, E. grandis ×E. urophylla and E. pellita. The phenological regimes of flowering of the parents have been summarized. The pollens stored under -18～-22℃ for 42 months after drying treatment could be kept with a germination ratio above 60%. Even trials involving 72 hybrids have been established. The results indicate that most of the hybrids have marked heterosis in volume accumulation when 3 years old. The best hybrids are tested to be E. urophylla× E. tereticornis and E. urophylla ×E. camaldulensis , with individual volume higher than that of the parents by 120.73% and 89.40% respectively.