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Oxygen isotope enrichment (Δ 18 O) reflects yield potential and drought resistance in maize
Author(s) -
CABRERABOSQUET LLORENÇ,
SÁNCHEZ CIRO,
ARAUS JOSÉ LUIS
Publication year - 2009
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2009.02013.x
Subject(s) - agronomy , stomatal conductance , photosynthesis , yield (engineering) , water stress , water use efficiency , dry matter , isotopes of carbon , transpiration , stable isotope ratio , chemistry , biology , botany , total organic carbon , ecology , materials science , physics , quantum mechanics , metallurgy
Measurement of stable isotopes in plant dry matter is a useful phenotypic tool for speeding up breeding advance in C 3 crops exposed to different water regimes. However, the situation in C 4 crops is far from resolved, since their photosynthetic metabolism precludes (at least in maize) the use of carbon isotope discrimination. This paper investigates the use of oxygen isotope enrichment (Δ 18 O) as a new secondary trait for yield potential and drought resistance in maize ( Zea mays L). A set of tropical maize hybrids developed by the International Maize and Wheat Improvement Center was grown under three contrasting water regimes in field conditions. Water regimes clearly affected plant growth and yield. In accordance with the current theory, a decrease in water input was translated into large decreases in stomatal conductance and increases in leaf temperature together with concomitant 18 O enrichment of plant matter (leaves and kernels). In addition, kernel Δ 18 O correlated negatively with grain yield under well‐watered and intermediate water stress conditions, while it correlated positively under severe water stress conditions. Therefore, genotypes showing lower kernel Δ 18 O under well‐watered and intermediate water stress had higher yields in these environments, while the opposite trend was found under severe water stress conditions. This illustrates the usefulness of Δ 18 O for selecting the genotypes best suited to differing water conditions.