Abstract
Storage of rice nursling seedlings berore transplanting is thought to be a cost-saving technique in rice culture. The objective of this study is to clarify the morphological changes of inner structures of stored rice seedlings under low temperatures(5.0, 10.0 and 12, 5°C) by means of observing every serial cross-section through the stem with a light microscope. Compared with the nursling seedlings just after raising at 5.O °C storage temperature, the stored seedlings showed a thinner leaf sheath and a decrcase in the number and size of the 2nd nodal tiller, but an incrcase in the number of crown root primordia. In the storage temperatures of 10.0 and 12.5°C, no changes occurred on the stemlength and size, on the size and number of nodal tillers, and on the inner strucures of leaf sheath and stem compared with the nursling seedlings just after raising, however, the number of crown root primordia incrcascd. After transplanting, the crown root primordia that had incrcased during storage emerged.These results indicate that in comparison with the nursling seedlings just after raising, the storage under low temperature before transplanting increases the number of crown root primordia of seelings without morphological changes of stem, leaf sheath, or tillers. Storage under 10.0 or 12.5°C before transplanting is available for rooting and growth after transplanting for rice nursling seelings.
