油菜 莢裂開性 程度의 品種間 差異

Varietal differences of pod dehiscence in rape seed

The pod dehiscence of rape is an important factor related to the harvest loss. To evaluate the varietal difference in the tendency of pod dehiscence, the breaking bending strengths of rape pod from 132 varieties were determined using a strain gauge type load cell. The breaking bending strengths were estimated treating each rape pod as a two-support beam and applying a dwonwared load at the center until the suture of pod breaks. Breaking bending strenths of the pods of easily dehiscent varieties were lower than those of medium and resistant varieties. Breaking bending strengths of pods measured by positioning the two lines of suture aligned vertically were lower than the measurements with the suture lines aligned horizontally. The positive correlation between the measurements with different positioning of pods was recognized at 0.01 probability level. Breaking bending strengths of the pod attached at upper part of main stem and primary branches were lower than those attached at medium and lower parts, and the mean value of those of the whole plant was about the same as the value of medium part. Therefore, it seems that the degree of pod dehiscence could be expressed by breaking bending strengths of the pods attached at medium part of the main stem and primary branch and with each pod positioned such that the lines of suture are aligned vertically. However, breaking bending strengths of the pod air-dried after harvest were lower than the values measured at harvest, and the positive correlation was recognized at 0.01 probability lvel. The breaking bending strengths were found to be positively correlated with width and thickness of pod, and the varieties resistant to pod dehiscence showed high values in the breaking bending strengths and thier width and thickness of the pod were larger. Rape cultivars, AB 120, Germany, Melchouski, Norin 35 and Naehan-yuchae showed higher resistant breaking bending strength of pod in the experiment. Therefore, it was concluded that AB 120, Germay, Melchouski, Norin 35 and Naehanyuchae were the most suitable cultivars as breeding material for higher yield and resistant pod dehiscence at the southern part of Korea.