Abstract
Mesocotyl growth habits of floating rice, single- and double-transplanting rice varieties in South Vietnam were examined in darkness. Results obtained were as follows :
1. An average mesocotyl length was longer than 31 mm in all the floating rices and it was shorter than 11 mm long in all the double-transplanting rices. In the single-transplanting rices, on the other hand, it varied from 1 to 105 mm long.
2. Not only in the floating rices but also in the single- and double-transplanting rices, the length-width ratio of grain was above 2.1.
3. Stimulation of mesocotyl elongation by high temperature pre-treatment was not observed in both single- and double-transplanting rices whose mesocotyl length was shorter than 4 mm, though it was clearly observed in japonica type rices in Japan.
