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Bread and Durum Wheat under Heat Stress: A Comparative Study on the Photosynthetic Performance
Author(s) -
Dias A. S.,
Semedo J.,
Ramalho J. C.,
Lidon F. C.
Publication year - 2011
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.2010.00442.x
Subject(s) - photosynthesis , chlorophyll fluorescence , stomatal conductance , transpiration , quenching (fluorescence) , chlorophyll , biology , agronomy , non photochemical quenching , electron transport chain , chemistry , botany , fluorescence , physics , quantum mechanics
The photosynthetic responses to heat stress, during grain filling, in four genotypes of Triticum aestivum L. (Sever and Golia) and Triticum turgidum subsp. durum (Acalou and TE 9306), chosen according to its genetic background diversity, were investigated. All wheat genotypes (excepting Golia) showed synergistic trends implicating the internal CO 2 concentration, net photosynthesis and stomatal conductance. Additionally, the modifications of net photosynthesis were associated with changes in stomatal control. Chlorophyll a fluorescence parameters (minimal fluorescence, maximal and variable fluorescence, intrinsic efficiency of PSII in darkness, non‐photochemical quenching, photochemical quenching and energy‐dependent chlorophyll fluorescence quenching) further pointed heat protective mechanisms, implicating F v /F m stabilization (i.e. maintaining the efficiency of PS II) and electron transport rate preservation. It is concluded that, comparatively to bread wheat, the photosynthetic performance of durum wheat is more tolerant to heat stress, as stomatal conductance and transpiration are less affected.