The aim of this field experiment was to investigate the possible effects of mepiquat chloride (TE) and trinexapac-ethyl (MC) on oil composition, seed yield and endogenous gibberellins content of flax cultivar. Foliar application of plant growth retardants mepiquat chloride (0.897, 1.794 and 2.691 kg a.i. ha-1) and trinexapac-ethyl (0.756, 1.512 and 2.668 kg a.i. ha-1) had significantly increased seeds ripening rate and seed yield. In contrast, plant height was decreased by foliar application of MC and TE. The application of MC significantly increased seed oil yield (730 kg ha-1 by 27.0%) compared to the control. Seed and oil yield, and unsaturated fatty acids (oleic acid, linoleic acid and linolenic acid) were increased by foliar application of MC.

The study was carried out to evaluate the affect of proton beam radiation on production of bulbil and tuber including change of endogenous gibberellins, of Dioscorea opposita Thunb. The yield of bulbils and tubers from non- and irradiated D. opposita Thunb at doses of 5, 10, 15 and 20 Gy were determined. Endogenous gibberellins were also quantified by GC/MS analysis. D. opposita tubers irradiated at 15 Gy produced higher bulbil production than non-irradiated plants. Enlarged bulbil (above size diameter 4 mm) was significantly increased at 15 Gy. Bioactive endogenous GA4 was dominant in bulbils and tubers irradiated with proton beam rather than GA1 . Major gibberellins biosynthetic pathways in bulbils and tubers of D. opposita plants were non C-13 hydroxylation route. From the results of this study, 15 Gy proton beam radiation was suggested as an optimal dose that can produce high amounts of bulbil for mass production of D. opposita plant.

본 연구는 '신고'배의 재배과정에서 만개 후 35일에 GA 도포제를 처리하여 발생하는 과대지의 변화와 과실특성 및 품질변화의 양상을 구명하고자 수행하였다. 이상발육 과대지의 발생률은 GA 도포제 무처리군 27.5%, 25 mg 처리군 52.5%로 유의한 차이를 나타냈고, 과대지수와 꽃 수는 이상발육 과대지에서 감소하였다. GA 도포제 처리 후 배생육기간 동안 GA 도포제 25 mg 처리군의 과실비대량이 무처리군에 비해 유의적으로 증가하였다. 또한

Proximate chemical components (protein, oil, carbohydrate, ash, fiber, and starch) were determined from tubers grown in upland and wetland conditions. The contents of crude protein, oil, carbohydrate, and starch were higher in upland condition than in wetland condition. Eight gibberellins were commonly identified and quantified in leaves and tuber of chufa grown in wetland and upland field during growing season. Gibberellin content was always higher specifically in the leaves and tubers grown in wetland condition than in those grown in upland condition. The current knowledge of gibberellin biosynthesis suggests that the two endogenous bio-active gibberellins both GA1 and GA4 are differently metabolized according to cultural conditions. Major gibberellin biosynthesis route is ascertained dominantly the non C-13 hydroxylation pathway leading GA4 in chufa plants.

This study was conducted in an effort to evaluate the effect of two gibberellin biosynthetic inhitiors, mepiquat chloride (MC 200, 400, 600 ppm) and trinexapac-ethyl ethyl (TNE 100, 200, 300 ppm) on flax (Linum usitatissimum L.) seed oil composition, growth characteristics and seed yield when applied at vegetative stage. A foliar spray of 600 ppm MC was found to be most effective, resulting in decreased plant height, and an increased seed yield (1,963 kg ha-1) with highest oil content (37.2 %). Ripened seed rate ranged 90.2 –91.9% in MC treated flax and 93.7- 94.1% in TE treated flax, respectively. MC treatment increased seed yield 10.9 – 21.6% and TNE treatment also increased 7.9 –11.8% compared to the control. The significant increase of flax seed yield in MC treatment was observed 600 ppm between these concentrations. Two gibberellin biosynthetic inhibitors, MC and TNE were 1.6 – 5.5% more ripened compared to the control. An increased unsaturated fatty acid was observed when higher concentration was applied to flax plant. Endogenous GA4 content was always higher than GA1 content in both MC and TE treatment.

Endophytic Aspergillus Fumigatus sp. LH02, isolated from the roots of soybean and indentified through phylogenetic analysis of 18S rDNA sequence, was found stimulatory to the growth of Waito-C rice seedlings among 13 other endophytic strains screened. In growth hormone analysis, pure culture of fungal isolate produced three gibberellins viz GA4, GA9 and GA12. To know the role and effect on soybean in endophytic association (EA) and non-endophytic association (NEA) under salt stress (70 and 140mM), experiment was carried out at growth chamber using complete randomized block design. The results elaborated that the EA has significantly increased the shoot length, shoot and root fresh and dry weights, chlorophyll content, photosynthesis rate and leaf area of the plants with and without salt stress compared to control. Field emission scanning electron microscope analysis of root's surface showed that EA plants were extensively colnized by Aspergillus fumigatus LH02 under high salanity. In phytohormonal anlysis, ABA contents in EA and NEA were almost similar. Howere, when plants were exposed th salt stress, ABA levels were found significantly low in EA compared to NEA plant. In isoflavone content analysis, aglycones, malonyl, acetyl and glucosides isoflavones (total 11 compounds) were analyzed for each treatment through extensive HPLC andalysis. The quantities of isoflavone were found higher in EA plant's leaves with and without salt stress compared to NEA plant leaves. In conclusion, such endophytic association can be beneficial to explore ways to improve crop production under stressful conditions.

For storage periods of tubers in Chinese yam, the levels of ~textrmGA44 and ~textrmGA20 was constant, meanwhile both ~textrmGA53 and ~textrmGA19 level were always higher than that of ~textrmGA44 and ~textrmGA20 ㆍ ~textrmGA9 content as precursor of ~textrmGA4 was not changed during storage. ~textrmGA24 content was low to below 0.2 ng for 90 days after storage, ~textrmGA36 content as precursor of ~textrmGA4 like ~textrmGA9 was about 6-8 fold higher than that of ~textrmGA9 during storage. GA contents of the two gibberellin biosynthetic pathways were gradually increased when storage periods were progressed. Bioactive GA1 content as the GA members of an early C-13 hydroxylation was always constant, and its content was very low as below 0.1ng per dry weight, meanwhile, bioactive ~textrmGA4 content as the GA members of non C-13 hydroxylation was drastically increased, also, its content was highest at 90 days after storage, and then decreased at 120 days after storage. Consequently, we suggest that ~textrmGA4 may be involved in controlling tuber sprouting in Chinese yam.

The metabolism of [14~textrmC ] ~textrmGA12 in the Chinese yam (Dioscorea opposita Thunb. var. Tsukune) was examined to determine the identification of endogenous gibberellins. [14~textrmC ] ~textrmGA12 was metabolized to ~textrmGA53 , ~textrmGA44 , ~textrmGA19 , ~textrmGA20 , ~textrmGA1 , ~textrmGA8 , ~textrmGA15 , ~textrmGA24 , ~textrmGA9 , ~textrmGA36 and ~textrmGA4 . Radioactivity of GAs in non C-13 hydroxylation route was five-fold higher than that of early C-13 hydroxylation in analyzed GA-metabolites. Radioactivity of ~textrmGA4 was always four times higher than that of ~textrmGA1 at every feeding time. ~textrmGA1 radioactivity has always a lower level to below 200 DPM. The major pathway of endogenous GA metabolism in seedlings of the Chinese yam might be the non C-13 hydroxylation pathway.

단일식물인 수수의 파이토크롬 B 돌연변이종(phyB-1)과 순계 야생종을 이용하여 phyB-1 변이종의 표현형에 미치는 지베렐린의 역할을 구명하고, 단일조건이 단일식물의 지베렐린 생합성 또는 대사를 어떻게 조절하는지를 조사한 결과를 요약하면 다음과 같다. 1. 지베렐린의 생합성 양은 하루 동안 일정한 수준을 유지하는 것이 아니라 주기를 가지고 변화하는 경향을 나타내어 식물호르몬 지베렐린은 리듬을 가지고 생합성되는 것으로 나타났다. 2. 단일식물인 수수의 야생종은 단일조건에서 보다 많은 양의 GA20 과 GA1 을 함유하고 있어 단일조건은 이들 지베렐린의 생합성을 촉진하는 것으로 나타났다. 3. 지베렐린의 함량은 같은 일장조건하에서도 시료채취 시기에 따라 큰 차이를 보여 파이토크롬B 변이종과 야생종간의 일관성있는 고유한 차이는 나타나지 않아 이들이 보이는 표현형의 차이는 지베렐린의 절대량의 차이보다는 지베렐린에 대한 반응의 차이에 의한 것으로 나타났다.

식물홀몬을 포함한 각종 식물생장조절물질의 생검법(bioassays or biological assays)을 소개 및 비교검토함과 동시에 일관성 있는 결과를 얻기 위한 몇가지 유의점을 지적코자 옥신류 생검에서는 녹두발근과 귀리제1절간장신장, gibberellin에서는 왜성벼의 제2엽신장과 왜성완두의 상조축신장, 그리고 cytokinin류에서는 무자엽생장, 담배줄기수캘러스생장, 그리고 오이자엽내엽록소형성 등의 방법을 요약하였다. 아울러 일련의 실험을 통해 얻어졌던 각종생장조절물질(특히 최근에 개발되는 각종 왜화제)에 대한 반응을 홀몬별로 요약 및 비교하였다.