Abstract
The objective of this study was carried out to investigate the proper plant growth regulator for increasing the number of flower, fruit set, and to enlarge the size of the berries in Ardisia pusilla. Flower bud formation was used rooted cutting, and fruit set, enlargement, and coloration of fruit were used with two years-old. $GA_3$ concentrations were treated with 0, 100, 200, or $400mg{\cdot}L^{-1}$. Flower bud formation was effective in $400mg{\cdot}L^{-1}$ $GA_3$ and it was 1.8 times greater than control. Plant growth regulators were applied by foliar spray at full bloom stage to increase the fruit set. As a result, $GA_3$ was the most effective for increasing fruit set. Also, auxins of 4-CPA (Tomatotone, Donbu hitech Co., Korea) and dichloprop triethanol amine (Antifall, Bayer Crop Science Co., Ltd., Korea) were effective. When $GA_3$ concentrations of 0.5 and $1.0mg{\cdot}L^{-1}$ were used, fruit set (%) reached to 70% and 77%, respectively. Effectiveness of $GA_3$ was 1.8 times greater than control. Also, auxins, dichloprop triethanol amine increased to about 7-12% during fruit setting, but cytokinin and anti-gibberellin were ineffective. To investigate the fruit enlargement and coloration, $GA_3$ was treated with 0.3, 0.6, and $1.2mg{\cdot}L^{-1}$. Fruit enlargement was achieved to about 15% by $GA_3$ $0.6mg{\cdot}L^{-1}$ when $GA_3$ was treated 3 times at the interval of 1 month per treatment when fruit size was about 2-3mm (after full-blooming two months). But anthocyanin contents for coloration of fruit skin were not significant according to $GA_3$ concentration. The results showed that $GA_3$ enhanced bud formation, fruit set and enlargement of fruit size in Ardisia pusilla.
$GA_3$에 의한 화아수 증진효과는 산호수 1년생, 생장조절제의 종류 및 농도에 따른 착과, 비대 및 착색 증진효과는 산호수 2년생을 사용하여 본 실험을 수행하였다. 그 결과, 화아수는 $400mg{\cdot}L^{-1}$ 처리구에서 가장 많았으며, 이는 대조구보다 약 1.8배 많이 형성되었다. 착과율 증진을 위해 산호수 만개시기에 생장조절제를 처리한 결과, $GA_3$와 auxin처리구의 착과율이 증진되었으며, 이 중 $GA_3$가 더 효과적이었다. $GA_3$에 의한 착과율은 0.5와 $1.0mg{\cdot}L^{-1}$ 처리시 각각 약 70%와 77%로 대조구보다 약 1.8배 증가되었다. 또한 Auxin 중 Dichloprop triethanol amine도 약 7-12%가 향상되었지만, cytokinin과 anti-GA는 효과가 없었다. $GA_3$에 의한 산호수 열매 비대효과를 알아보기 위해 만개 2달 후 열매 지름이 약 2-3mm되었을 때 0.3, 0.6, $1.2mg{\cdot}L^{-1}$를 1달 간격으로 3회 처리한 결과, $0.6mg{\cdot}L^{-1}$에서 약 15% 향상되었다. 그러나, 과피의 안토시아닌 측정에 의한 착색정도는 $GA_3$ 처리농도에 따라 유의한 차이가 없었다. 즉, 산호수에 있어서 $GA_3$는 화아수, 착과, 열매 비대를 증진시키는데 효과적인 것으로 나타났다.
