BGN 6: In vitro pollination of barley with rye and bread wheat BARLEY GENETICS NEWSLETTER, VOL. 6, II. RESEARCH NOTES
Grunewaldt, pp. 29-30

II.13 In vitro pollination of barley with rye and bread wheat.

J. Grunewaldt, Max-Planck-Institut für Züchtungsforschung,Abteilung Straub, 5 Köln 30, BRD

Interspecific or even intergeneric hybridization may solve some of the actual breeding problems in barley, like: straw stiffness, kernel quality, resistance, cross fertilization ability, etc. Only exceptional combinations between barley and grasses of other species or genera yield hybrids, the amount being normally very low.

Bates et al. (1974) injected animal-effective immunosuppressants into plants and obtained after this treatment hybrid embryos and some plants from crosses between barley and durum wheat, bread wheat, rye, Triticale and oats.

In order to get a better control of the interactions between the immunosuppressants and the fertilization and by this possibly a better hybrid yield, we added E-amino caproic acid (EACA) after filter sterilization to different agar media. The most effective composition was that out of Linsmaier and Skoog (1965) macro- and micro elements plus 0.2mg/1 IAA, 0.4mg/1 BAP, 10 mg/l thiamine, 30g/1 saccharose, 8g/1 agar, 0.5 or 1.0mg/1 EACA, pH 5.8.

About ten days before natural pollination, ovules from barley cv. Ortolan were excised from sterilized spikelets, put on the media mentioned above and incubated at 26°C and an 8 hr light period. Two to three days later the pollination with barley pollen (control I), rye cv. Somro and bread wheat cv. Kolibri was performed Seven to ten days after pollination 80% - 90% of a total of 400 ovules showed stimulation of ovule-length growth and inhibition of further stigma development. In contrast to this, unpollinated ovules, grown as control II, exhibit an overall thickening and no stop in stigma growth. About 30 days after pollination the material was analyzed cytologically. All combinations had well developed "endosperm" in about 80% of ovules cultivated; but only 20% of them yielded embryos in the cross barley x barley (control I), about 2% in the cross barley x rye and less than 1% in the barley x wheat combination. The embryoculture of this material is still underway.

The low amount of embryos obtained in the barley x barley cross indicates that an alteration of the technique and the culture media used may increase the number of fertilized egg cells and embryo development also in crosses between barley x rye and barley x wheat.

References:

Bates, L.S., A. Campos V., R. Rodriguez R., and R.G. Anderson, 1974: Progress toward novel cereal grains. Cereal Science Today 19, 283-285.

Linsmaier, E.M. and F. Skoog, 1965: Organic growth requirements of tobacco tissue cultures. Physiol. Plant. 18, 100-127.

BGN 6 toc
BGN Main Index