禾木科植物染色体消除型远缘杂交的研究进展

植物远缘杂交是作物育种中广泛应用的技术。除了核型稳定的种间杂交可以获得杂种以外，还可以利用核型不稳定的种间杂交后父本染色体消除的现象，通过胚培养和染色体加倍处理获得加倍单倍体(DH)植株。然而从小麦×玉米杂交获得的DH后代与其理论上应完全同质的遗传表现却不相符，总有2～5％的DH植株发生了形态学变异。最近的研究证明。通过小麦×玉米的受精作用，一些玉米特异DNA可以被转移到小麦DH后代的基因组中。

Advances in Karyotypically-Unstable Wide Crosses(Chromosome Elimination System) in Gramineae

Wide hybridization is a most widely used technique in crop breeding programs. In addition to karyotypically stable crosses which give rise to hybrid plants, karyotypically unstable crosses, i. e., the chromosome elimination systems, can be used to produce doubled haploid (DH) plants through embryo rescue and doubling treatment. However, 2 ～5 % of the wheat DH progenies from wheat × maize crosses have morphological variations, which are incompatible with their theoretical homogeneity. Recently, it was proved at DNA level that some maize-specific DNAs were transferred into wheat DH progenies through fertilization between wheat and maize.