Variation for winter hardiness generated by androgenesis from
Festuca pratensis × Lolium multiflorum amphidiploid cultivars with different winter susceptibility
Androgenic populations produced from three Festuca pratensis × Lolium multiflorum amphidiploid (2n = 4x = 28) cultivars show wide within population variation for winter hardiness. Populations comprising a total of 423 androgenic plants derived from 23 donor plants from 3 Polish F. pratensis × L. multiflorum cultivars Felopa, Sulino, and Rakopan were studied over 3 years (1999–2002) in a field experiment at Lopuszna, Poland (20∘08′E, 49∘28′N, altitude 568 m). The results indicate that despite differences in winter hardiness between the three amphidiploid cultivars, the mean winter hardiness of androgenic progeny from each cultivar was the same. Thus an androgenesis component in a plant breeding programme may provide an opportunity to recover winter hardy genotypes from high yielding cultivars that are themselves adapted poorly to stress conditions. Androgenesis also evoked variation in snow mould resistance. In this case, androgenic plants with the greatest snow mould resistance were recovered from the least winter hardy donor cultivars and plants. The results indicated the low importance of snow mould resistance as a component of winter hardiness under the field conditions used for these experiments.
The potential role of androgenesis in cytoplasmic-nuclear phylogenetic discordance.
In many organisms, gene trees based on nuclear mark ers and those based on cytoplasmic markers (chloroplasts or mitochondria) sometimes indicate quite different re lationships among the species being studied (e.g., Rieseberg and Soltis 1991; Rieseberg et al. 1996; Cathey et al. 1998; Bergthorsson et al. 2003; Avise 2004; Croucher et al. 2004; Sullivan et al. 2004; Chan and Levin 2005; Fehrer et al. 2007; Linnen and Farrell 2007). This in congruence is normally attributed to incomplete lineage sorting (when two al?eles coalesce prior to speciation and do not track the species phylogeny), introgression (interspecific hybridization followed by unidirectional backcrossing), horizontal gene transfer, or errors in phy logenetic reconstruction. Although the usual explanations for cytoplasmic nuclear incongruence are well documented, these expla nations are often assumed rather than demonstrated in
Studies on the composition, quality and processing of triticale. Part II. Mineral composition of grain and flour.
Mineral composition of grain and flour in 14 promising triticale strains from India are reported. The mean values for whole grain, i.e. Ca (0.47 mg/g), P (2.70 mg/g), K 4.60 mg/g, Na (352 micrograms/g), Zn (41.6 micrograms/g), Cu (7.0 micrograms/g), Fe (73.4 micrograms/g) and Mn (33.6 micrograms/g) were obtained as compared to those of flour, i.e. Ca (0.27 mg/g), P (0.97 mg/g), K (1.64 mg/g), Na (231 micrograms/g), Zn (26 micrograms/g), Cu (4.0 micrograms/g) and Mn (10.5 micrograms/g), respectively. These values were found to be considerably higher than those of wheat. Highly significant positive correlations of ash with sodium and zinc in whole grain were observed. In the case of triticale flour, highly significant positive correlations of ash with manganese, phosphorus and potassium were obtained.