II. 29. C-banding pattern of Asiatic taxa of Hordeum.
Ib Linde-Laursen, Risø National Laboratory, DK-4000 Roskilde; Roland von Bothmer and Niels Jacobsen, Institute of Systematic Botany, Gothersgade 14, DK-1123 Copenhagen K, Denmark.
Within the project on wild species of Hordeum (Bothmer and Jacobsen 1978), until now the C-banding patterns of the following, perennial taxa of Hordeum from Asia were studied, viz. the selfcompatible species H. bogdani Wil. (2n = 14) and H. roshevitzii Bowden (2n = 14, 28), and the self-incompatible taxa in the polymorphic H. brevisubulatum-group, viz. H. brevisubulatum (Trin.) Link ssp. violaceum (Boiss. & Hohen.) Tzvelev (2n = 14, 28) and ssp. turkestanicum (Nevski) Tzvelev (2n = 28, 42). In agreement with the conditions in other self-incompatible species, C-banding pattern polymorphism was assumed to be frequent in the chromosomes of the two latter taxa. This might create difficulties in establishing their correct basic C-banding patterns. Therefore, besides spontaneous material, F1 hybrids ssp. violaceum (2x) x H. vulgare and ssp. turkestanicum (6x ) x H. vulgare were used for the investigation. The C-banding procedure was published earlier (Linde-Laursen 1975). The C-banding patterns of the hybrids corresponded to those of their parental plants.
The C-banding patterns of H. bogdani and H. roshevitzii consisted of mostly centromeric or juxtacentromeric bands with few conspicuous bands located more distally. Their C-banding patterns resembled those of Hordeum species earlier published (Linde-Laursen 1975, 1978; Vosa 1976). Besides having centromeric and juxtacentromeric bands, the C-banding patterns of H. brevisubulatum ssp. violaceum (2x) and ssp. turkestanicum (6x) had rather large to large telomeric C-bands on most chromosome arms. Thus, within the genus Hordeum, the C-banding patterns represent two banding types. It remains to be seen whether types with C-banding patterns intermediate between these two will be found. Although a restricted material of each taxon was studied, C-banding pattern polymorphism was observed in all taxa.
We have got living material of another two central Asiatic taxa belonging to the H. brevisubulatum group, viz. ssp. nevskianum (Bowden) Tzvelev and an undescribed taxon from Iran (Bothmer 1979). Their C-banding patterns will also be clarified. However, to complete our study of the perennial taxa of Hordeum in Asia we lack living material of H. brevisubulatum ssp. brevisubulatum, which occurs in eastern Siberia, Mongolia, and northeastern China. If anybody has got living material of this taxon, we should be most grateful to receive plants or seeds.
References:
Bothmers R. von. 1979. Revision of the Asiatic taxa of Hordeum sect. Stenostachys. Bot. Notiser 132 (3) (in press).
Bothmer, R. von and N. Jacobsen. 1978. A project on wild species of Hordeum. BGN 8:2-3.
Linde-Laursen, I. 1975. Giemsa C-banding of the chromosomes of 'Emir' barley. Hereditas 81:285-289.
Linde-Laursen, I. 1978. Giemsa C-banding of barley chromosomes. I. Banding pattern polymorphism. Hereditas 88:55-64.
Vosa, C.G. 1976. Chromosome banding patterns in cultivated and wild barleys (Hordeum spp.). Heredity 37:395-403.