林木三倍体育种研究进展及展望

Research progress and prospect of triploid breeding of forest trees

植物三倍体具有生长迅速、叶片或花、果实硕大、新陈代谢旺盛、适应性强以及不孕等特点,尤其适用于无性繁殖林木的遗传改良.利用配子染色体加倍或四倍体与二倍体杂交等有性多倍化技术手段,增加目标树种一套基因组的全部同源基因,可以仅通过一轮次的育种过程实现多目标性状综合改良,培育出生长快、纤维长、木素低、纤维含量高以及抗逆性增强的用材林新品种,或者是生长迅速、叶片和果实等器官巨大、含胶量及药物成分含量显著提高的胶用、漆用、药用、叶用、果用新品种.在人工诱导配子染色体加倍选育三倍体时,实现有效处理时期的即时判别是提高三倍体育种效率的关键,而选配高配合力亲本则是提高三倍体育种效果的保障.随着林木三倍体育种理论和技术方法的突破及其不断向其他树种拓展,三倍体育种必将在提高林产品产量、改善品质以及增强抗逆性等方面发挥更大的作用.

Triploid plants characterized by fast growth,large leaves or flowers and fruits,high level of metabolism,good adaptability and sterility,triploid breeding is especially suitable for genetic improvement of tree species with good ability of vegetative propagation.Because triploids production by gametic chromosomal doubling or crossing tetraploid with diploid can make target tree species increase a set of homologous genes,new varieties characterized by fast growth,longer fiber,lower lignin,higher holocellulose and stress resistance for timber could be developed.Triploid new varieties with multiple use,such as gum,lacquer,medicine,leaves and fruits,which characterized by fast growth,large leaves and fruits,higher gum and pharmaceutical ingredient could also be achieved.Therefore,triploid breeding could improve multiple traits only by one round of breeding procedure.When triploid produced by induction of gametic chromosome doubling,determination of effective treating stages is the key factor to increase efficiency of triploid production.However,parental selection with higher combining ability was considered to be a guarantee for increasing effects on triploid production.As the breakthrough of theories and techniques in triploid breeding of tree species and its application to other species going on,it is believed that triploid breeding will play an important role in increasing yield of forest production,improving wood quality and stress resistance.