Genotypic Differences in Thermotolerance are Dependent Upon Pre-Stress Capacity for Antioxidant Protection of the Photosynthetic Apparatus in Cotton

Cotton is exceptionally sensitive to high temperature during reproductive development, with a negative correlation existing between high temperatures during flowering and yield (Oosterhuis, 2002). Furthermore, reproductive thermosensitivity in cotton is closely associated with the photosynthetic thermosensitivity of the subtending leaf (Snider et al., 2009). For example, high temperature is known to cause significant declines in fertilization efficiency (Snider et al., 2009) and carbohydrate content of the cotton pistil (Snider et al., 2009) along with declines in net carbon fixation of major source leaves (Bibi et al., 2008; Snider et al., 2009).