Fig. 3
From: Heat Stress During Gametogenesis Irreversibly Damages Female Reproductive Organ in Rice
Different types of abnormalities that occurred during embryo sac development in IR64 exposed to six days of heat stresses (38 °C—HT38; 40 °C—HT40) during gametogenesis. (A) Degenerated megaspore mother cell (yellow arrow indicates the missing nuclei); (B) All four megaspores degenerated, indicated by yellow arrows; (C) Abnormal two-nucleate embryo sac, with both nuclei degenerated (yellow arrows); (D) Abnormal two-nucleate embryo sac with one nucleus degenerated (yellow arrow), white arrow shows the remaining one active nucleus. (E) Abnormal two-nucleate embryo sac without a large vacuole and both nuclei located at the micropylar region (Two nuclei indicated by white arrows were supposed to be located one each at micropylar and chalaza end, similar to Figure 2E). (F) Abnormal eight-nucleate embryo sac with missing nuclei (yellow arrows); (G) Abnormal eight-nucleate embryo sac with degenerated egg apparatus (yellow arrows indicate the degenerated egg cell and synergids); white arrow indicates two active nuclei; and (H) Shrunken embryo sac