The role of crown roots from coleoptilar node in the rooting and development of transplanted rice nursling seedlings.

摘要

The root system of rice seedlings is composed of a seminal root and crown roots from the coleoptile node. In pot experiments, the roots of rice cv. Sasanishiki were cut at various locations, and the treated seedlings were grown for seven days aftertransplanting to clarify the role of the crown roots in rooting and development. Even when the roots were cut at 1.5 cm from the base of the root, growth of the seedlings was similar to that of the control. However, growth was significantly reduced whencut at a length of 0.5 cm from the base. The growth of transplanted seedlings, including the emergence rate of the third leaf, was barely influenced by excision of the root tips of a seminal root and four crown roots, but growth was severely reduced by cutting at the bases of a seminal root and the longest crown root. Growth of transplanted seedlings decreased in accordance with the total root length remaining after the treatments. These results indicate that the rooting and development of transplantedseedlings are reduced according to the total length of the root remaining after treatment. It is suggested that the crown roots from the coleoptile node play a large role in the absorption of water and nutrients just after transplanting, and promote therooting and development of transplanted seedlings through emergence of the first nodal roots.