title: Genetic variation in the efficiency of nitrogen utilization and photosynthetic activity of flag leaves among the old and modern germplasm of winter wheat.
abstract: 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.
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszynska 34, 60-479 Poznań, Poland. agor@igr.poznan.pl
authors.forename: Andrzej G
authors.initials: AG
authors.lastname: Górny
authors.forename: Sebastian
authors.initials: S
authors.lastname: Garczyński
authors.forename: Zofia
authors.initials: Z
authors.lastname: Banaszak
authors.forename: Bogusława
authors.initials: B
authors.lastname: Ługowska
mesh_terms: D000222:Adaptation, Physiological; D000704:Analysis of Variance; D001947:Breeding / Q000379:methods; D014644:Genetic Variation; D005838:Genotype; D009584:Nitrogen / Q000378:metabolism*; D010788:Photosynthesis / Q000235:genetics / Q000502:physiology*; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology*; D019655:Quantitative Trait, Heritable; D013045:Species Specificity; D014908:Triticum / Q000235:genetics*
chemical_list: D009584:Nitrogen