ABSTRACT
Triticeae is a big tribe with a large number of species, including important cereal crops common wheat, durum wheat, barley, rye, and triticale. Interspecific hybridization and allopolyploidy have played important roles in Triticeae speciation and evolution. Common wheat has a highly heterogeneous and plastic genome structure that is the product of two allopolyploidization events involving the A, B, and D genomes. The ancestral lineages of the three genomes are also thought to contain ancestral hybridization events between diploid species. Hence, common wheat is an important model system for investigation of biological mechanisms and genetic systems related to interspecific hybridization. As well, artificial allopolyploids and interspecific hybrids have been widely used incommon wheat improvement. The donor species of common wheat have been successfully used to enhance genetic diversity of common wheat through homologous recombination. However, most species in the Triticeae are wild species that do not share
Allopolyploidy and Interspecific Hybridization for Wheat Improvement Dengcai Liu1,*, Ming Hao2, Aili Li3, Lianquan Zhang4, Youliang Zheng5 and Long Mao6
1 Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China; Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China, E-mail: dcliu7@yahoo.com
2 Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China, E-mail: haomingluo@foxmail.com
3 National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China, E-mail: liaili@caas.cn
4 Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China, E-mail: zhanglianquan1977@126.com
5 Triticeae Research Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, China, E-mail: ylzheng@sicau.edu.cn
6 National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China, E-mail: maolong@caas.cn
* Corresponding author
homologous genomes with wheat. A beneficial trait from a wild species can be used in wheat breeding via a collinear translocation between homoeologous chromosomes. However, it is cumbersome to develop a collinear translocation that contains target genes but not undesirable linked genes. To date, only a few wheat-alien homoeologous translocations have been successfully used in commercial cultivars. The utilization of highthroughput technologies in identification of alien introgressions will accelerate identification and tracking of tiny introgressions. In future, more and more small introgressions without linkage drag are expected to be used as operational modules in wheat breeding.
