벼 湛水表面直播에 있어서 뿌리形質과 倒伏抵抗性의 關係

Relationship between root characters and lodging resistance of rice in direct seeding on flooded paddy surface

To determine the character useable for indicator of root-lodging resistance and to understand the relationship between the root-lodging resistance and root characteristics at sixty days after seeding and/or at twenty days after heading, and beween those and canopy characteristics of rice plant, forty four rice varieties or promising lines were grown under direct seeding on flooded paddy surface. Root dry weight(RDW), top dry weight(TDW), root diameter(RD), RD×RDW and RD×root length(RL) were significantly different among five rice groups classified by degree of lodging(0~9). The degree of root-lodging showed significant negative correlation with both RD or RD×RDW and RL or RD×RL. RD, RDW, RD×RDW and RD×RL showed considerably high heritability, while RL showed relatively low one. The characters greatly contributed to root-lodging resistance positively or negatively were RD×RL, RD×RDW, RD, RL and RDW at sixty days after seeding. Both TDW and RDW at sixty days after seeding were highly associated with those at twenty days after heading. The resistant rice varieties to root-lodging in field revealed thicker root(RD : 0.81㎜＜) than the susceptible one(RD : ＜0.65㎜) at sixty days after seeding. The varieties below 0.35 in RD×RDW showed 5~7 degree of root lodging in field, while those of 0.36~0.44, 0~3, and those above 0.45 in RD×RDW did not exhibited root lodging.