title: Water- and nitrogen-dependent alterations in the inheritance mode of transpiration efficiency in winter wheat at the leaf and whole-plant level.
abstract: The effects of contrasting water and nitrogen (N) supply on the observed inheritance mode of transpiration efficiency (TE) at the flag-leaf and whole-season levels were examined in winter wheat. Major components of the photosynthetic capacity of leaves and the season-integrated efficiency of water use in vegetative and grain mass formation were evaluated in parental lines of various origins and their diallel F(2)-hybrids grown in a factorial experiment under different moisture and N status of the soil. A broad genetic variation was mainly found for the season-long TE measures. The variation range in the leaf photosynthetic indices was usually narrow, but tended to slightly enhance under water and N shortage. Genotype-treatment interaction effects were significant for most characters. No consistency between the leaf- and season-long TE measures was observed. Preponderance of additivity-dependent variance was mainly identified for the season-integrated TE and leaf CO(2) assimilation rate. Soil treatments exhibited considerable influence on the phenotypic expression of gene action for the residual leaf measures. The contribution of non-additive gene effects and degree of dominance tended to increase in water- and N-limited plants, especially for the leaf transpiration rate and stomatal conductance. The results indicate that promise exists to improve the season-integrated TE. However, selection for TE components should be prolonged for later hybrid generations to eliminate the masking of non-additive causes. Such evaluation among families grown under sub-optimal water and nitrogen supply seems to be the most promising strategy in winter wheat.
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznań, Poland. dwas@igr.poznan.pl
authors.forename: Dominika
authors.initials: D
authors.lastname: Ratajczak
authors.forename: Andrzej G
authors.initials: AG
authors.lastname: Górny
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D002678:Chimera / Q000502:physiology; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D014644:Genetic Variation; D040582:Inheritance Patterns; D009584:Nitrogen / Q000378:metabolism*; D010641:Phenotype; D010788:Photosynthesis; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology*; D054046:Plant Stomata / Q000502:physiology; D018526:Plant Transpiration; D012621:Seasons; D012639:Seeds / Q000502:physiology; D012987:Soil / Q000032:analysis; D014908:Triticum / Q000235:genetics / Q000502:physiology*; D014867:Water / Q000378:metabolism*
chemical_list: D012987:Soil; D014867:Water; D002245:Carbon Dioxide; D009584:Nitrogen