Open AccessCytological studies of a dihaploid and hybrid from intergeneric cross Elymus shandongensis × Triticum aestivum
Author(s) -
LU B. R.,
BOTHMER R.
Publication year - 1990
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1990.tb00401.x
Subject(s) - chiasma , biology , meiosis , elymus , chromosome , genetics , pairing , homologous chromosome , gene , genome , botany , poaceae , superconductivity , physics , quantum mechanics
One dihaploid (n=2x=14) and one true hybrid (2n=5x=35) were produced from the intergeneric cross Elymus shandongensis X Triticum aestivum. The dihaploid was a result of selective elimination of T. aestivum chromosomes early in embryo development. Meiotic chromosome behaviour was studied in the parents, dihaploid, and hybrid. E. shandongensis (2n=4x=28) and the hexaploid wheat formed only bivalents at metaphase I. Some homoeologous chromosome pairing with an average of 0.68 bivalents, ranging from zero to four, and a very low frequency of trivalents was observed in the dihaploid. This reveals a low affinity between S and Y genomes of E. shandongensis. A haplo‐insufficient (hemizygous ineffective) genetic control of homoeologous chromosome pairing may also exist in the species. Homologous chromosome association in the hybrid (0.25 chiasmata/cell) was distinctly lower than in the dihaploid (0.73 chiasmata/cell). This indicates that chromosome pairing suppressors, e.g., the Ph gene system, in T. aestivum could affect homoeologous chromosome pairing between the genomes of wild species.