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4 Journal of Applied Genetics

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Genetic structure and phylogenetic relationships of the Polish Heavy Hors

100%

Iwanczyk E. , Juras R. , Cholewinski G. , Cothran E. G.

tom 47

nr 4

353-359

In this study a wide range of genetic markers (12 microsatellites, 7 blood-group loci, 10 blood-protein loci) and mitochondrial DNA (mtDNA) were used to assess genetic diversity in Polish Heavy horses. Three random samples were sequenced for 421 bp of the mitochondrial D-loop region, but no clear phylogenetic patterns were seen in mtDNA variation. Both heterozygosity and diversity levels are fairly high in Polish Heavy horses. In phylogenetic analysis the draught horses form a distinct cluster that pairs with the true pony breeds. Within this 'cold-blooded' group, the Polish Heavy Horse clusters most closely with the Posavina breed from Croatia and the Breton breed from France. From the standpoint of genetic conservation, the Polish Heavy Horse does not appear to be in jeopardy.

Genetic variation in the efficiency of nitrogen utilization and photosynthetic activity of flag leaves among the old and modern germplasm of winter wheat

100%

Gorny A. G. , Garczynski S. , Banaszak Z. , Lugowska B.

tom 47

nr 3

231-237

Genotypic variation in major components of the efficiency of nitrogen utilization and photosynthetic activity of flag leaves among old (released 1881?1963) and modern (released 1969?2003) cultivars of winter wheat was studied in field conditions under varied N fertilization levels (110, 90 and 80 kg N ha?1). Significant genotypic differences were observed for all characters. Their heritabilities ranged from 0.37 to 0.93 and were the lowest for the leaf efficiency of gas exchange, photosynthetic rate, straw N content and the economic index of N utilization efficiency (NUE). Some modern cultivars exhibited an enhanced tolerance to N shortage and several attributes of efficient N utilization (e.g. later senescing and more photosynthetically active flag leaves, increased ability to redistribute N into grains). The genotypes may serve as donors of appropriate characteristics for breeding. The observed cultivar-by-fertilization interactions suggest, however, that evaluations under diverse fertilization regimes may be necessary when searching for improved wheat efficiency and adaptation to less favourable environments.

Genetic variation and population structure of three Trifolium species

100%

Bulinska-Radomska Z.

Journal of Applied Genetics

1996

tom 37

nr 2

153-160

Three dipoloid Trifolium (Fabaceae) species, T.campestre, T.fragiferum and T.montanum, were electrophoretically assyed to elucidate the range anf organization of genetic variation in relation to the mating system, reproduction mode and longevity of the species.T.campestre, is an annual self-pollinated species, T.fragiferum and T.montanum are cross-pollinated perennials.The former species reproduces both sexually and vegetatively, whereas the latter solely on sexual reproduction.Several populations of each species collected throughoutnPoland were surveyed for 15 enzymes.The measures of variation included:proportion of polymorphic loci per population, average number of alleles per locus, average gene diversity (He) and genetic distance (D).To describe the organization of diversity in each species, total genetic variation per locus (Ht) was calculated.Both cross-polinated species had more polymorphic loci, higher numbers of alleles per locus and higher level of diversity than self-pollinated T.campestre.Most of genetic variation of the latter species was allocated among polulation unlike in T.fragiferum and T.montanum.

Genotype-dependent variation in the transpiration efficiency of plants and photosynthetic activity of flag leaves in spring barley under varied nutrition

100%

Krzeminska A. , Gorny A. G.

nr 4

481-489

In the study, spring barley genotypes of various origin and breeding history were found to show a broad genetic variation in the vegetative and generative measures of the whole-plant transpiration efficiency (TE), photosynthesis (A) and transpiration (E) rates of flag leaves, leaf efficiency of gas exchange (A/E) and stress tolerance (T) when grown till maturity in soil-pots under high and reduced NPK supplies. Broad-sense heritabilities for the characteristics ranged from 0.61 to 0.87. Significant genotype-nutrition interactions were noticed, constituting 19-23 % of the total variance in TE measures. The results suggest that at least some ?exotic? accessions from Ethiopia, Syria, Morocco and/or Tibet may serve as attractive genetic sources of novel variations in TE, T and A for the breeding of barleys of improved adaptation to less favourable fertilisation.