CYTOGENETICS OF SOME NATURAL INTERGENERIC HYBRIDS BETWEEN ELYMUS AND AGROPYRON SPECIES

Abstract

The occurrence of natural interspecific hybrids between Elymus and Agropyron species was detected and verified by cytomorphological studies. The hybrids were highly vigorous and resembled Elymus species in vegetative growth habit, although their spikes were sterile, and intermediate between the putative parents in morphology. Chromosome pairing in the hybrids was highly irregular with 14 to 28 univalents per cell. The formation of up to seven bivalents, with mean frequencies of 2.86 to 3.14 per cell in different hybrids, was attributed to homoeologous relationships existing between the genomes of E. innovatus (JJXX) and those of Agropyron species (SSHH).