Research progress and prospect of triploid breeding of forest trees

Abstract

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.