II.9 Induction of haploids from anthers in vitro.
J. Grunewaldt and S. Malepszy, (1) Max-Planck-Institut für Züchtungsforschung, Abteilung Straub, 5 Köln 3D, BRD.
(1) Permanent address: Polish Academy of Science, Inst. of Plant Genetics, Poznan, Poland.
The significance of haploids in genetics and plant breeding has been widely discussed recently. Connected with this discussion a great deal of effort has been made to produce tissues or even whole plants with the haploid chromosome number. Of the many genera examined, it seems that success is restricted to the dicotyledonous species but little or no success has been reported for monocots.
In 1973 we commenced a program to produce barley (Hordeum vulgare L.) haploids by anther culture. Anthers with pollen in the tetrad stage were plated on a modified Linsmaier and Skoog medium (see Malepszy and Grunewaldt, 1974) and incubated in the dark at 26°C. Out of nine genotypes involved only seven yielded calluses after about four weeks. The best result was obtained in cv. Vogelsanger Gold with 32% calluses of anthers plated. About half the callus forming anthers showed more than one callus per anther.
The highest percentage of haploid, diploid and polyploid cells in any
of the subclones from individual calluses were 14%, 65% and 73%, respectively.
The organ regeneration took place after about seven weeks, that is,
in three weeks old calluses. It was preceded by the formation of green
or whitish looking clusters, from which the first leaf emerged. Different
callus strains yielded various numbers of plants, ranging from O to more
than 200 (see Table 1). The capacity to differentiate reaches an optimum
and decreases subsequently with further subcloning.
Table 1. In vitro plantlet induction from anther calluses of cv. Amsel subcloned for ten cycles.
Of about 1,000 plantlets obtained only four have been green, all others are chlorophyll-less. Root-tip cells from three of the green plants showed the haploid chromosome number x = 7. Among the albino plants, however, haplold, diploid and polyploid somatic chromosome counts were made.
Reference:
Malepszy, S. and J. Grunewaldt. 1974. Ein Beitrag zur Erzeugung von Haploiden bei Hordeum vulgare L. Z. Pflanzenzüchtg 72: 206-211.
