HYBRIDIZATION BETWEEN TRITICUM-AESTIVUM L AND AGROPYRON-MICHNOI ROSHEV .1. PRODUCTION AND CYTOGENETIC STUDY OF F1 HYBRIDS

Intergeneric hybrids between Triticum aestivum cv 'Chinese Spring' (2n = 6x = 42, AABBDD) and Agropyron michnoi Roshev. (2n = 4x = 28, PPPP) were obtained by embryo culture. Their spike characteristics were similar to those of common wheat but, unlike their parents, they were long-awned. The average meiotic chromosome pairing at MI of F1 hybrids was: 6.39 I + 3.75 rodII + 8.64 ringII + 0.81 III + 0.30 IV + 0.04 V, the bivalent and multivalent formation of which was much higher than expected from the genomic formulae. It is especially worthwile to note that the F1 hybrids were self-fertile, self set being 0.15%, and seeds were easily obtained from the backcross of F1 plants with hexaploid and tetraploid wheats; here the seed set was more than 20.0%. The polyploid taxa and the position of A. michnoi in Agropyron are discussed.