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Relationship between Carbon Isotope Discrimination, Mineral Content and Gas Exchange Parameters in Vegetative Organs of Wheat Grown under Three Different Water Regimes
Author(s) -
Zhu L.,
Li S. H.,
Liang Z. S.,
Xu X.,
Li Y.
Publication year - 2010
Publication title -
journal of agronomy and crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.095
H-Index - 74
eISSN - 1439-037X
pISSN - 0931-2250
DOI - 10.1111/j.1439-037x.2009.00404.x
Subject(s) - anthesis , transpiration , stomatal conductance , agronomy , water use efficiency , water content , horticulture , poaceae , water stress , biology , chemistry , photosynthesis , botany , cultivar , irrigation , geotechnical engineering , engineering
Carbon isotope discrimination (Δ) has been proposed as an indirect selection criterion for transpiration efficiency and grain yield in wheat. However, because of high cost for Δ analysis, attempts have been made to identify alternative screening criteria. Ash content (m a ) has been proposed as an alternative criterion for Δ in wheat and barley. A pot experiment was conducted to analyse the relationship between Δ, mineral content and gas exchange parameters in seedlings and leaves of bread wheat ( Triticum aestivum L.). Plants of 10 genotypes were cultivated under three different water regimes corresponding to moderate (T 3 ), intermediate (T 2 ) and severe drought (T 1 ) stress obtained by maintaining soil humidity at 75 %, 55 % and 45 % of the humidity at field capacity respectively. Δ and m a in seedlings and leaves showed significant differences among the three water treatments. Significant positive correlations were found between Δ and m a in seedlings and leaves at elongation and anthesis stages in severe drought stress (T 1 ). Δ was negatively associated with potassium (K) content in intermediate drought stress (T 2 ) and positively with magnesium (Mg) content in T 2 and T 3 (moderate drought stress) in flag leaf at anthesis. There were negative correlations between Δ and single‐leaf intrinsic water‐use efficiency ( W T ) in T 2 and T 3 at anthesis stage. Stronger positive associations were noted between Δ and stomatal conductance ( g s ) in T 1 and T 2 than in T 3 at anthesis. These results suggested that Δ is a good trait as an indirect selection criterion for genotypic improvement in transpiration efficiency, while m a is a possible alternative criterion of Δ in wheat vegetative organs, especially in stressed environments. Significant association was found between Δ and K, Mg and Ca contents that would merit being better investigated.