Fig. 1. Measurement of anther characteristics. A, Exterior of rice anther. Anther length (L) was taken as the length of the long locule. Anther width was calculated as the mean width taken in two directions [(W₁+W₂)/2]: one parallel to the stomium (W₁) and the other (W₂) at right angles. B, Schematic transverse section of anther. C, Magnification of B around the cell layers separating the locule from the lacuna formed between the septum and the stomium. The number of cell layers separating the lacuna from the locule between the septum and the stomium was counted at the point where the number of cell layers was smallest (the probable breaking point when the septum opens; between arrowheads). La, Lacuna formed between the septum and the stomium; En, endothecium; Ep, epidermis; T, tapetum; Lo, locule; St, stomium.