Selection effectiveness of lodging tolerance by using pushing resistance for improving rice cultivar adapted to direct sowing culture in flooded paddy fields

This study was undertaken to find the selection effectiveness of lodging to lerance by using pushing resistance for improving rice cultivar adapted to direct sowing culture in flooded paddy fields. The lines used in the experi ment were F, and F, breeding lines of Aoinokaze//Lemont/Hinohikari; 47 line s and Yumehikari//Lemont/Hinohikari; 29 lines that were medium maturity lin es. There was a significant negative correlation between the pushing resist ance of F-4 lines in transplanting culture and lodging degree of F-5 lines in direct sowing culture. Even though the selection rate of pushing resista nce in F-4 was changing from 10% to 40% there was a distinct difference in lodging degree under direct sowing culture in F-5. A few F-6 lines selected by using pushing resistance in transplanting culture were superior in lodg ing tolerance and yielding ability under direct sowing culture. There were comparatively few deviations of yielding ability and grain quality by using pushing resistance for the selection of lodging tolerance in an early gene ration. These results lead to the conclusion that it is possible to breed h igh lodging tolerance cultivar adapted to direct sowing culture by using pu shing resistance under transplanting culture in an early generation.