Shoot and the fruit growth characteristics of ‘Campbell Early’ grape cultivar were investigated after vine thinning using the main branch leader. Before vine thinning, branch diameter was 11.8 ㎜, but it decreased to 9.3 ㎜ after vine thinning. The number of shoots per vine increased to 55.9-64.5 after vine thinning. The number of fruit clusters per shoot was higher (1.5-1.75) in the vine thinning plot than in the control (0.8). Consequently, the number of clusters per vine was 98.1–106.5 in the vine thinning plot, while that in the control was 24.4-28.0. However, soluble sugar content (SSC) and tartaric acidity showed no significant differences between the control and the vine thinning plot. The proportion of >351 g fruit cluster weight after vine thinning (81.0%) was significantly higher than that of the control (32.5%). These results imply that fruit quality based on the variation in cluster weight and fruit yield was enhanced by vine thinning using the main branch leader.

Ionizing radiation directly and indirectly affects gene expression within the plant genome. To access the physiological response of rice to different types of ionizing radiation, rice seeds were exposed to gamma-ray and ion beam radiation. Exposure to ionizing radiation dramatically decreased the shoot length compared with non-irradiated plants. Fluorescence-activated-cell-sorting (FACs) was used to measure DNA contents. There were significant correlations of dose-dependent between irradiated plant and non-irradiated plant. The radicals induced by the ionizing radiation in the plant could be observed by electron spin resonance (ESR). It was confirmed that the number of free radicals in cell was greatly increased all irradiated plants than non-irradiated plant. A significant positive correlation was shown between ionizing radiation dose and signal intensity. In order to determine the Genetic diversity, AFLP analysis was conducted with the irradiated plant and non-irradiated plant. Based on band patterns, the cluster analysis was conducted to evaluate the genetic variation by using the UPGMA (Unweighted Pair Grouping Method of Averages). Genetic diversity of irradiated plants by low dose ion beam was the closest non-irradiated plant and irradiated by high dose gamma-ray was the furthest from non-irradiated. We describe the detailed methods of ionizing irradiation and discuss its applications in genetic research as well as plant breeding.

포도 송이다듬기는 많은 노동력이 필요하므로 노동력을 감 소시킬 수 있는 새로운 송이다듬기 기술을 개발하기 위하여 연 구를 수행하였다. 포도의 송이다듬기 기술은 지경솎기가 알솎 기에 비하여 작업효율성이 6.7배 높은 것으로 나타났다. 과실 품질은 지경솎기 및 알솎기가 무처리구보다 과방과 과립수가 적지만 가용성 고형물은 높고, 산도는 낮게 나타났으며 압상률 도 적은 것으로 나타났다. 송이다듬기에 의한 포도의 송이 품질 균일도를 조사하기 위해 송이의 기부, 중간 및 선단 부분의 가용 성 고형물 함량과 산도를 측정한 결과 350~450 g의 과방중을 가진 포도송이가 송이 내 위치에 따른 품질의 차이가 나타나지 않아 적합한 것으로 판단되었다.

포도 대목 품종 육성 시, 주요 교배친으로 사용되는 대목 품종 29점 및 국내 자생 머루를 포함한 포도 속(Vitis) 야생 유전자원 13점 등 총 42점의 유전적 다양성을 분석하기 위하여 RAPD와 SSR 분석을 수행하였다. Random decamer 30 종을 분석하여 329개의 다형성 밴드(60.3%)를 얻었으며 primer 당 평균 다형성 밴드 수는 11.0개였다. SSR 마커 20종을 이용하여 분석한 결과 263개의 대립인자가 확인되었고, 마커