II. 8. Frequency of tetraploid and triploid androgenetic plants of winter barley (Hordeum vulgare L.).
W. Friedt and B. Foroughi-Wehr, Biologische Bundesanstalt fur Land- und Forstwirtschaft, Institut fur Resistenzgenetik, D-8059 Grunbach, Federal Republic of Germany.
The anther culture technique previously described for spring barley (Foroughi-Wehr et al. 1982) has been successfully adapted to winter barley now (Foroughi-Wehr et al. 1983). F1 hybrids including the Barley Yellow Mosaic Virus (BaYMV) resistant cultivar 'Franka' (6-rowed) as a common parent were used as anther donor plants. For comparison, anthers of the parents were also cultured in vitro and up until now a total of about 200 green androgenetic plants have been regenerated.
Until the end of 1982, the chromosome numbers have been determined of 139 plantlets grown in soil in the greenhouse. The overall results are summarized in Fig. 1: 20 plants (14.9%) are haploid (2n=x=7), Fig. 2), 98 (70.5%) are diploid (2n=2x=14), 3 (2.2%) are triploid (2n=3x=21, Fig. 3), and 18 (12.9%) are tetraploid (2n=4x=28). These frequencies are very similar to those reported earlier for androgenetic spring barley (Friedt and Foroughi-Wehr 1980). Since about the same proportions are also observed in androgenetic progeny of rye (Secale cereale), it is speculated that the mechanism(s) of spontaneous chromosome doubling leading to diploid and polyploid plants out of an originally haploid cell, may be identical or similar in different cereal species.
Figure 2. Haploid root tip cell of winter barley (2n=x=7).
Figure 3. Triploid root tip cell of winter barley (2n=3x=21).
The data of Figure 1 demonstrate that the vast majority of androgenetic winter barley plants, i.e. 85%, are haploid or spontaneously doubled haploid, i.e. homozygous diploid. These lines can immediately be used in laboratory tests for BaYMV-resqstance as well as in field trials for evaluation of yield components. Therefore, homozygous diploid breeders' strains can be provided by the doubled-haploid method two or three years earlier than by conventional breeding methods.
The triploid and tetraploid lines which are grown in the greenhouse now are summarized in Table 1, where the respective ancestry is also given. Seed of these plants will be free for distribution.
Table 1. Androgenetic triploid and tetraploid winter barley lines produced in 1982.
References:
Foroughi-Wehr, B., W. Friedt and G. Wenzel. 1982. On the genetic improvement of androgenetic haploid formation in Hordeum vulgare L. Theor. Appl. Genet. 62:233-239.
Foroughi-Wehr, B., W. Freidt and G. Wenzel. 1983. High frequency of androgenetic plant production in winter barley (Hordeum vulgare L.). P1. Sci. Lett. (submitted).
Friedt, W. and B. Foroughi-Wehr. 1980. Microspore derived chromosome number and structural variants of barley (Hordeum vulgare L.). BGN 10:16-20.
