Studies on the Starch Contained in the Tissues of Rice Plants : XV. Properties of starches from culm and endosperm of glutinous and non-glutinous rice plant of different polyploidy

Abstract

Some properties of the starches contained at culm and endosperm were compared between glutinous (cv. Saitamamochi, cv. S) and non-glutinous (cv. Norin No. 8, cv. N)rice plants of different polyploidy (haploid x to tetrapliod 4 x). The results obtained are summarized as follows: 1. Alkali decomposition values of culm starches varied among polyploids, and they were greater than those of endosperm starches. The glutinous endosperm starches showed a stronger resistance to alkali. 2. Absorption curves of iodine-starch complexes of both culm and endosperm starches varied more or less between cv. N and cv. S and among polyploids. The peaks of absorption curve of culm starches were observed with blue color at 600 to 610 nm wave lengths, except cv. N-4 x which had a peak at a little shorter wavelength. The curves of endosperm starches of cv. N and cv. S had peaks at the shorter wavelengths than those of culm, being near 560 nm with purple color in the former and at 520 to 530 nm with purplish red color in the latter. 3. The absorption curves of iodine-starch complexes obtained from endosperms ripened at different air temperatures were almost similar, but the starch ripened at 35°/30°C (day/night) showed a stronger peak at a shorter wavelength than that at 25°/20°C. 4. X-ray diffraction patterns of endosperm and culm starches gave A type and B type patterns, respectively, and no clear difference was observed among polyploids and between cv. N and cv. S.