Analysis of the relationship between leaf-emergence date and length of organs on the main culm in rice plant under a given environmental condition

In order to examine the regularity of shoot development in rice plants, we determined the relationship between leaf-emergence date and the length of various organs on the main culm of cv. Koshihikari and Nipponbare under given culturing conditions. (1) The emergence date of the 14th leaf correlated in a highly negative manner with the 15th and 16th laminae lengths and the 14th and 15th sheath lengths, however it correlated in a highly positive manner with the IV and V internode lengths. (2) The plants having 17 leaves on the main culm showed an earlier emergence of the 14th leaf, longer laminae at the upper position and shorter internodes at the lower position than those having 16 leaves. (3) When the total leaf number was the same, the plants having the longest laminae at the upper position on the main culm indicated earlier emergence dates of the 14th leaf, longer laminae at the upper position and shorter internodes at the lower position. Even when the emergence date of the 14th leaf was the same, longer laminae at the upper position and shorter internodes at the lower position were observed on planes having the longest laminae at the upper position.