| New protein bands in an amphiploid of Aegilops caudata
and Ae. umbellulata J. Giles WAINES1) and B. Lennart JOHNSON Department of Agronomy, University of California, Riverside, California 92502, U.S.A. The principle of additivity of protein patterns in hybrids of known parcentage was demonstrated for Stipa x Oryzopsis (HALL & JOHNSON 1963), for hybrids between Solanum species (DESBOROUGH & PELOQUlN 1966) and for Aegilops bicornis x Ae. squarrosa (BERWER, SING & SEARS 1969). For both seed and tuber storage proteins and for Aegilops enzyme proteins the pattern of the hybrid was a simple addition of the two parental patterns. Moreover, the hybrid pattern could be simulated by an in vitro mixture of the parental proteins (JOHNSON, BARNHART & HALL 1967). DESBOROUGH and PELOQUIN (1966) reported some Solanum hybrids which had extra protein bands not present in the parents and we wish to report the same phenomenon in Aegilops. A seed of Aegilops caudata G 593 (2n=14) x Ae. umbellulata G 494 (2n=14) was obtained and germinated. Tillers of the hybrid plant were separated, established as independent plants and colchicine solution applied after the method of BELL (1950). Some of the treated plants produced seed. The spike morphology of the fertile hybrid (2n=28) is intermediate between the two parents Ae. caudata and Ae. umbellulata (Figure 1 on the Cover) and closely resembles the morphology of Ae. triuncialis (2n=28) as previously reported for a hybrid of similar parentage (KIHARA 1954). This supports KIHARA'S hypothesis that Ae. triuncialis arose as a natural allopolyploid from a hybrid of Ae. caudata and Ae. umbellulata. Enough seed was gathered from the fertile hybrids to make a protein extraction with 70% ethanol. A protein sample was electrophoresed on acrylamide gel following the method of JOHNSON (1967). The electrophoretic spectra of both parents, of the amphiploidi and of a mixture of parental protein in a ratio of 1 : 1 are illustrated in Fig. 2. There appear to be two slow mooing bands at 1.0 cm. and 1.4 cm. from the origin of the amphiploid spectrum (Fig. 2a) which are not present in the parents (Fig. 2c-d) or the mixture (Fig. 2b). Apart from these amphiploid bands, all bands present in the parents are present in the amphiploid and in the mixture. The density of bands in the amphiploid compared with bands in the mixture is not the same, particularly the band at 5.5 cm. from the origin. Nevertheless, the electrophoretic pattern of this amphiploid is very similar to those of Ae. triuncialis biotypes (WAINES 1969) again supporting KIHARA'S original hypothesis. |
| 1) Present address : Botany School, Oxford OXI 3RA, England. |
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