Figure 3.

Abnormal female gametophyte development (megagametophytogenesis) at three stages of flower development in ‘Panda’ and PA15 genotypes of common buckwheat under control (20 °C) and thermal stress (30 °C) conditions. Abnormal vacuolization of egg cells of ‘Panda’ (upper insert in (a)) and of PA15 open flowers at 30 °C (b), at the chalazal pole three antipodal cells visible (lower insert in a); degeneration of 2–4-nucleate embryo sac of ‘Panda’ bud at 20 °C (arrow, c), of egg cell in PA15 open flowers at 20 °C (arrow, d), and of egg apparatus (arrow, e), ovule (arrow, f), and stamens (arrowhead, f) of ‘Panda’ open flowers at 30 °C. Paraffin sections stained with Ehrlich’s hematoxylin combined with Alcian blue. The number of analyzed flowers per treatment at each stage of development was 15–32 in two replicates.