1998 Volume 67 Issue 2 Pages 159-164
This study was undertaken to determine the plant characteristics which might be associated with lodging resistance for the selection of good eating-quality rice cultivars well adapted to direct sowing cultures in northern Kyushu.Six plant characteristics on lodging resistance were compared among highly palatable Japanese rice cultivars, Japanese cultivars with high lodging resistance and USA cultivars.Highly palatable Japanese rice cultivars showed smaller breaking strength of the culm, and thinner culm and crown root than other cultivars.The culm length showed a significant (p<0.05)positive correlation with the fresh weight of the straw per culm and a significant(P<0.01)negative correlation with culm thickness.The breaking strength of the culm showed a significant(P<0.001)positive correlation with the fresh weight of the straw per culm and culm thickness.A principal component analysis based on six characteristics was applied to good eating-quality rice cultivars.The first principal component was interpreted as "shape"factor, which was concerned with the culm thickness, breaking strength of the culm and crown root thickness.The second component was interpreted as "size"factor, which was concerned with plant height.The first principal component score showed a significant(p<0.01)negative correlation with lodging degree under direct sowing cultures.But, there was no correlation between the second component score and lodging degree.Therefore, there was no relationship found between the culm length and lodging degree.These results indicate that it is possible to use culm thickness, breaking strength of the culm and crown root thickness as an indicator of estimating characteristics of lodging resistance under direct sowing cultures.The characteristics can also be utilized for the selecting good eating-quality rice cultivars with high lodging resistance well adapted to direct sowing cultures in northern Kyushu.
