Bread and Durum Wheat under Heat Stress: A Comparative Study on the Photosynthetic Performance

Abstract

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 CO2 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 Fv/Fm 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.

Leaf Photosynthesis During Grain Filling Under Mediterranean Environments: Are Barley or Traditional Wheat More Efficient Than Modern Wheats?

“…This is in line with the report from Dias et al. (), comparing photosynthetic rates in bread and durum wheat cultivars under heat stress conditions, where the leaf photosynthesis was similar between both species under heat stress and superior in bread wheat under optimal conditions.…”

“…In fact, and despite the range of environments explored, traditional wheat or barley did not show a superior overall P N than modern wheat (quite the opposite in general for the WB experiments). This is in line with the report from Dias et al (2010), comparing photosynthetic rates in bread and durum wheat cultivars under heat stress conditions, where the leaf photosynthesis was similar between both species under heat stress and superior in bread wheat under optimal conditions. The lack of consistent relation between differences in grain yield and flag leaf photosynthesis reinforces the concept that measurements carried out at individual plant level do not always correlate with the performance of the crop.…”

Early heat waves over Italy and their impacts on durum wheat yields

“…In general, durum wheat is more tolerant to heat stress when compared with soft wheat, as stomatal conductance and transpiration are less affected by high temperature (Dias et al, 2011). Nevertheless, durum wheat frequently experiences heat stress in the regions where it is mainly grown (southern Europe, western Asia, and northern Africa).…”

The effect of heat waves, elevated [CO2] and low soil water availability on northern red oak (Quercus rubra L.) seedlings

“…Roden & Ball, 1996;Qaderi et al, 2006;Ow et al, 2008) or comparing a constant elevation in temperature to ambient conditions (e.g. Berry & Bjö rkman, 1980;Gunderson et al, 2009;Dias et al, 2011;Djanaguiraman et al, 2011;Wertin et al, 2011). Way & Oren (2010) concluded in a review of such studies that elevated temperatures enhanced growth in most tree species.…”