Fruit Characteristics of Gaeryangmeoru Grapes According to Gibberellic Acid and Thidiazuron Treatments

The present study was conducted to establish an effect and a proper concentration for treatment with gibberellic acid ($GA_3$) and thidiazuron (TDZ), resulting with increase berry size and yield in Gaeryangmeoru grapes. Berry size was increased by treatment with $GA_3$, and the fruit clusters obtained for the groups treated with $GA_3$ concentrations of 100 and $200mg{\cdot}L^{-1}$ were bigger. The berry number was also enhanced in $GA_3$ treated groups, but the soluble solid content and acidity was not significantly different. Damage caused by $GA_3$ treatment, such as peel pollination and berry shatter, was observed in the group with $200mg{\cdot}L^{-1}$. The berry size was larger in group treated with a high concentration of $GA_3$ and TDZ respectively than in those treated with low concentrations in the treatment mixed $GA_3$ and TDZ; however, fruit with low soluble solid content and high acidity was harvested after $GA_3$ and TDZ treatment due to delay of berry ripening. The pericarp tissue layers were not changed, but the distance from the epidermis layer to vascular bundle tissue was increased as a result of $GA_3$ and TDZ treatment. Therefore, $GA_3$ and TDZ did not affect an cell division but not cell size, resulting in an enlarged berry size. It is necessary to treat plant growth regulators 2~3 times and immediately after berry set to enhance berry set rate, because the period of berry set is short. This study suggests that the proper concentration for enhancing berry size and set were up to $100mg{\cdot}L^1$ $GA_3$ or $50mg{\cdot}L^{-1}GA_3+1.25mg{\cdot}L^{-1}$ TDZ, and it is necessary to pay attention to harvest mature fruits because of the delay of ripening caused by the usage of TDZ.

Gibberellic acid와 thidiazuron 처리에 의한 개량머루의 과실 특성

개량머루의 과립 크기와 생산량을 증가시키기 위한 $GA_3$와 TDZ 처리의 효과와 적정 처리 농도를 구명하기 위하여 본 실험을 수행하였다. $GA_3$ 처리는 모든 처리구에서 모두 과립 비대 효과를 보였으며 100과 $200mg{\cdot}L^{-1}$ 처리구의 과립이 가장 컸다. 또한 $GA_3$ 처리구는 착립수가 증가하여 과방중이 크게 생산되었으나 당도 및 산도에 전혀 차이가 없었다. $200mg{\cdot}L^{-1}$ 처리구에서 과피 오염 및 탈립과 같은 약해가 발생되었다. $GA_3$와 TDZ 혼용 처리에서는 $GA_3$ 혹은 TDZ의 농도가 높은 처리구의 과립이 크기는 크지만 과실의 성숙이 지연되어 당도가 낮고 산도가 높은 과실이 수확되었다. $GA_3$와 TDZ를 처리했을 때 과피 조직은 세포층수에는 변화 없이 유관속 조직까지의 길이가 증가하였다. 따라서 개량머루의 $GA_3$ 와 TDZ처리는 세포 분열에는 영향 없이 세포 크기가 증가됨으로 인해 과립 크기가 증가하였다. 개량머루는 착립이 결정되는 시기가 짧기 때문에 착립 직후 2~3회에 나누어 처리해야 착립률을 향상시킬 수 있었다. 개량머루의 과립 비대와 착립률을 향상시키기 위해서는 $GA_3$ $100mg{\cdot}L^{-1}$ 이하의 단독 처리 혹은 $GA_3$ 50+TDZ $1.25mg{\cdot}L^{-1}$의 혼용 처리가 적합할 것으로 판단되었고 TDZ 처리에 의해 과실의 성숙이 지연되므로 성숙과를 수확하도록 주의해야 할 것으로 생각된다.