Growth Characteristics and Germanium Absorption of Brasica juncea C. with Different Types of Germanium Compounds in Hydroponic Cultivation

게르마늄 종류별 양액재배시 갓의 생육특성 및 게르마늄 흡수 특성을 조사하기 위해 갓 재배시 무기게르마늄 ($GeO_2$)과 유기게르마늄 (Ge-132)을 농도별로 각각 처리하여 게르마늄 독성발생 범위, 생장반응, 갓 부위별 게르마늄 함량 그리고 갓의 게르마늄 흡수량 및 흡수율을 조사하였다. 무기 및 유기게르마늄 모두 $10mg\;L^{-1}$까지는 생육저해 현상이 거의 없었으나, Ge $25mg\;L^{-1}$ 이상부터는 심한 생육저해 현상을 보여 Ge 75 및 $100mg\;L^{-1}$에서는 새싹 생성이 거의 되지 않을 정도로 저해현상이 나타났다. 대조구와 비교 하였을 때, 무기게르마늄은 Ge $5mg\;L^{-1}$ 처리까지, 유기게르마늄은 Ge $10mg\;L^{-1}$ 처리까지 지상부 및 지하부 생장반응이 대조구에 비하여 약간 증가되는 경향이었다. 게르마늄의 흡수량을 살펴보면 무기게르마늄의 경우 총 흡수된 게르마늄 중 지상부인 잎에 약 70%, 지하부인 뿌리에 약 30%가 분포되어 있었다. 유기게르마늄의 경우에는 무기게르마늄과는 반대로 잎에 약 23%, 뿌리에 약 77%로 뿌리에 훨씬 많이 분포되어 있었다. 초기 용액 내 투여된 게르마늄에 대한 식물체내 흡수율을 부위별로 살펴보면, 무기게르마늄의 경우 지상부에서 2.4~4.3% 범위로 평균 약 3.0%이고, 지하부에서 0.2~0.7%범위로 평균 약 0.4%이었다. 유기게르마늄의 경우에는 지상부에서 1.2~2.1% 범위로 평균 약 1.7%, 지하부에서는 0.5~0.9% 범위로 평균 약 0.8%이었다. To investigate the effect of inorganic ($GeO_2$) and organic (Ge-132) germanium treatment on Brasica juncea C. plant, growth characteristics and Ge contents were examined with various inorganic or organic germanium treatments (0, 5, 10, 25, 50, 75 and $100mg\;L^{-1}$), respectively. Brasica juncea C. growth did not much inhibited until Ge $10mg\;L^{-1}$ concentration under both Ge-132 and $GeO_2$ treatments as compared to control. On the other hand, at Ge concentration higher than $25mg\;L^{-1}$ concentration, Brasica juncea C. growth was inhibited under both Ge-132 and $GeO_2$ treatments. Under treatment of $GeO_2$, length of root and shoot slightly increased until $5mg\;L^{-1}$ concentration and dry weight slightly increased until $10mg\;L^{-1}$ concentration. Under treatment of Ge-132, length of root and shoot slightly increased until $10mg\;L^{-1}$ concentration and dry weight slightly increased until $25mg\;L^{-1}$ concentration. Total Ge contents in Brasica juncea C. early seedlings with $GeO_2$ treatment were a bit higher than those with Ge-132 treatment. Germanium was primarily accumulated in the roots (77%) with organic Ge (Ge-132) treatments, whereas Ge was primarily accumulated in the leaf (70%, respectively) with $GeO_2$ treatments. The Ge uptake rates in inorganic Ge treatments were slightly high than those in organic Ge treatments. Under inorganic Ge treatment with $2.5mg\;L^{-1}$, about 3% of Ge was accumulated into plant and distribution in leaf and root was 84.8% and 15.2%, respectively. Under organic Ge treatment with $2.5mg\;L^{-1}$, about 2.6% of Ge was accumulated into plant and distribution in leaf and root was 66.4% and 33.6%, respectively.