Abstract
For the purpose of raising the level of selection efficiency in sugarcane breeding, it is necessary to establish selection criteria which can be eliminated reasonably a mass of the first stage seedlings. Standard characters for selection are to be chosen from practical ones which have higher heritability and correlation between each stages.
It is the purpose of this study to investigate a relationship of some practical characters between the first seedling stage and the successive clonal stages of sugarcane raised at Tanegashima Isle, South Western region of Japan, the results bling summerized as follows.
1) Correlation coefficients for stalk length, stalk biameter and pithiness ratio were all highly positive and significant, r values ranging from 0.5 to 0.7. Elimination in the early stages of evaluation would have been highly effective based on these three characters.
2) Numbers of millable stalk and weight per stool were highly correlated under the condition diminishing competition among seedlings in planting distance 85×85 cm. It is expected that productivity of seedling stage is reliable in such condition, whereas correlations for number of millable stalk were reduced by about r=0.3 as planting density increased in seedling population.
3) Correlation coefficients for Brix between the same clones in 1967, 68 were all positive ranging from 0.2 to 0.6. Frequency distribution of Brix used 299 clones is shown in Fig.1. It is evident that selection for Brix based on single stool would have been as effective in obtaining clones with high Brix and eliminating those with low Brix.
4) It may be possible to examine the period for suitable and early selection.
