Cytology, fertility, and morphology of Elymus kengii (Keng) Tzvelev and E. grandiglumis (Keng) A. Löve (Triticeae: Poaceae)

Abstract

This study reports on the cytogenetics, fertility, mode of reproduction, and morphological variation of two perennial Triticeae grasses, Elymus kengii (Keng) Tzvelev and Elymus grandiglumis (Keng) A. Löve, from west central China. Both species are allohexaploids (2n = 42), self-fertile, and morphologically distinct on the basis of their plant color, glume length, and lemma and rachis vestiture. F1 hybrids between these two species are partially fertile and morphologically intermediate to their parents. Analysis of chromosome pairing in hybrids between E. grandiglumis or E. kengii and the following "analyzer" species, Psathyrostachys juncea (Fisch.) Nevski (NN), Psathyrostachys huashanica Keng (NN), Elymus lanceolatus (Scribn. &Smith) Gould (SSHH), Elymus dentatus (Hook. f.) Tzvelev ssp. ugamicus (Drob.) Tzvelev (SSYY), Elymus ciliaris (Trin.) Nevski (SSYY), Pseudoroegneria spicata (Pursh) A Löve (SS), and Pseudoroegneria tauri (Boiss. &Bal.) A. Löve (SSPP), suggested that both taxa contain the S, Y, and P genomes. This represents a new genome combination not previously reported and shows that the P genome from the crested wheatgrasses (Agropyron) has been involved in polyploid evolution within the. Triticeae.Key words: genome, meiosis, chromosome pairing, interspecific hybrids, Elymus, Triticeae.