抄録
In this paper, a morphological complex characteristic of rice varieties was estimated by principal component analysis using all the data of three nitrogen feltilizer levels at each plant spacing level (spacings in the row were 5 cm, 15 cm and 25 cm, respectively). The present results obtained were as follows: (1) A morphological complex characteristic of each variety at each plant spacing level can be shown by two principal components which are indices of the morphological characteristic. These indices were as follows: 5 cm plot X1=0.506x1+0.381x2-0.170x3-0.170x4+0.512x5+0.574x6 X2=-0.278x1+0.452x2+0.588x3+0.608x4+0.059x5+0.053x6 15 cm plot X1=0.450x1+0.227x2-0.332x3-0.357x4+0.462x5+0.532x6 X2=-0.307x1+0.605x2+0.462x3+0.482x4+0.200x5+0.142x6 25 mm Plnt X1=0.425x1+0.194x2-0.321x3-0.341x4+0.462x5+0.550x6 X2=-0.294x1+0.644x2+0.474x3+0.503x4+0.247x5+0.151x6 (2) The meaning of the first index in each plant spacing was mainly concerned with the total weight per plant of the variety at given condition. (3) The meaning of the second index was different in each plant spacing; namely, in the 5 cm plot it was mainly concerned with the plant type whether variety was a long-culmed, heavypanicle type or short-culmed, tillering type. But, in the 15 cm and 25 cm plots, these were concerned with the quantity of individual plant yield of variety together with the plant type mentioned above.
