MORPHOLOGICAL IDENTIFICATION OF ELYMUSSIBIRICUS,E.NUTANS,AND E.BURCHAN-BUDDAE,AND THEIR GENOMIC RELATIONSHIPS
ELYMUS SIBIRICUS,E.NUTANS和E.BURCHAN-BUDDAE的形态学鉴定及其染色体组亲缘关系的研究

In order to investigate morphological variations of Elymus sibiricus L. , E. nut ans Griseb. , and E. burchan-buddae (Nevski) Tzvelev =Roegneria nutans (Keng) Keng], and to explore their systematic relationships, six morphological characters were measu red and compared between the Elymus species. Interspecific hybridizations between E. nut ans and E. sibiricus, and E. burchan-buddae were carried out with the aid of embryo resctre. Chromosome pairing behaviour was also analysed at metaphase- I of meiosis in pollen mo th-er cells of F, hybrids. Morphologic characters, such as length of spikes and length of glumes varied considerably between different individuals of each species, whereas length and width of paleas were quite stable and different between species. The interspecific hybrids were completely sterile and their meioses were irregular. Meiotic configuration of E. nutansXE. l,ur-chan-buddae was 7. 70 I 13. 40 I 0. 06 I 0. 08 W , whereas that of E. sibiricusX E. nutans was 11. 98 I 9. 61 I 0. 64 I 0. 39 W 0. 01 V . It is concluded from the morphological and cytological study that (1) it is possible to identify the three Elymus spe;cie;3 using the palea character, in addition to other traditionally applied characters; (2) Elymus nutans and E. burchan-buddae have a comparatively high genomic relationship, while E.. nutans and E. sibiricus have a relatively low genomic affinity to one another; and (3) a ce rtain chromosome pairing regulator was presented in the hybrid between E. burchan-buddai; and E. nutans.