본 연구는 생육시기별 한지형 잔디인 왕포아풀에 생장조정 제 trinexapac-ethyl(TE)과 prohexadione-calcium(PC) 을 처리 시 잔디의 품질 변화와 생장 억제 효과를 조사하였다. 처리구는 대조구와 생장조정제 처리구인 TE 처리구와 PC처리 구로 설정하였다. 1차 시험(여름철, 8월)과 2차 시험(가을철, 10월) 조사에서 대조구와 비교하였을 때, 왕포아풀의 가시적 품질 및 엽록소 함량은 통계적으로 유의적인 차이는 없었고, 약해는 발생하지 않았다. TE와 PC처리 후 28일 경과 시 잔디 초장은 1차 시험에서 대조구보다 각각 34.9%와 32.2% 정도, 2차 시험에서는 35.5%와 33.8% 정도 감소하였다. 대조구와 비교 시 TE와 PC처리구의 잔디 예지물은 1차 시험에서 각각 47.2%와 45.0%씩, 2차 시험에서 35.6%와 31.0%씩 감소되 었다. 생육시기별 비교에서 TE는 약제처리 후 28일 경과 시, PC는 7일 경과 시 각각 1차 시험에서 생장 억제 효과를 나타 냈다. 상기 결과들의 종합한 결과는 TE와 PC 처리 시 왕포아 풀에서 약해가 발생하지 않았고, 잔디의 경엽신장과 예지물을 감소시키는 것을 확인하였다. 또한, 생장조정제는 잔디 관리 에서 여름철과 가을철 모두 이용할 수 있으나 여름철에 생육 억제 효과가 높게 나타났다.

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.

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.

Gibberellic acid did not affect ethylene production, whereas gibberellin biosynthesis inhibitors triggered ethylene production in dormant tubers. Gibberellic acid did not induce sprouting of dormant tubers, however, treatment of gibberellin biosynthesis retardants enhanced sprouting rates. Sprouting rate in ancymidol-treated tubers was highest among gibberellin biosynthesis retardants. Sprouting rate of tubers treated with ancymidol increased to 91.4~% . Batatasin-III content in GA3 treated tuber was increased in the highest concentration (30~mug~;I-1) . Tubers treated with mepiquat chloride, Batatasin-I was increased steadily, but contents of Batatasin-III and V showed dramatic decrease at the 1,000~mug~;I-1) concentration. This infers that gibberellin biosynthesis retardants play key roles in promoting breaking dormancy on dormant tubers of Chinese yam.

The objective of this study was to ,determine trinexapac-ethyl [4-(cyclopropyl- α -hydroxy-me-thylene)-3,5-dioxocyclohexanecarboxylic acid ethyl ester] effects on lodging-related traits of rice varieties treated at different application rates and times. Trinexapac-ethyl WP was applied at the rate of 10, 20 and 30g ai/l0a to Heukjinjubyeo and Daeanbyeo, respectively. Effects of trinexapacethyl varied greatly with application time as well as application rate with little differences between rice varieties. As the application rate increased, lodging index, center of gravity and exsertion of panicle above flag leaf decreased, whereas breaking strength and phytotoxicity increased. Exsertion of panicle was greatly influenced by the application time with a little difference by application rate. The most effective application time of trinexapac-ethyl based on lodging index and total internode length (Ist-4th node) was 2DBH(days before heading) in Heukjinjubyeo and 17DBH in Daeanbyeo, resulting in reducing total internode length by 12.9 and 9.7cm, respectively. A significant reduction was found at the 1st, 2nd, and 3rd internodes in Heukjinjubyeo, while at the 2nd and 3rd internodes in Daeanbyeo. No significant difference was found among treatments in the panicle length of both rice varieties but the panicle fresh weights of Daeanbyeo were significantly greater in all trinexapac-ethyl treatments compared with that of the control when measured 20 days after heading. Consequently, trinexapacethyl treatment significantly improved lodging-related traits of rice plants without affecting rice yield and yield components

Trinexapac-ethyl[ 4-(cyclopropyl- α -hydroxy-methylene)-3,5-dioxocyclohexane carboxylic acid ethylester] is a growth-retardant for plants by inhibiting a key step in biosynthesis of GA. A treatment of trinexapacethyl generally induces a reduction in vegetative growth and also inhibits heading. In addition, the trinexapacethyl was known to enhance the freeze-tolerance in annual bluegrass, however, the mechanism is not known yet. One possible reason for the enhanced freeze-tolerance may be the antifreeze protein known to be accumulated in intercellular space of the leaf during cold acclimation. In order to see the possible in-duction of the synthesis of antifreeze proteins by trinexacpacethyl, the apoplastic proteins extracted from Kentucky bluegrass treated with trinexapacethyl were analyzed by SDS-PAGE and the presence of the antifreeze protein was observed. In addition, western analysis showed the identity of the protein induced by both a cold acclimation and a trinexapacethyl treatment. It appears that an enhanced freeze-tolerance of the turf grass by trinexapacethyl is due to the synthesis and/or accumulation of the antifreeze protein similar to the enhanced freeze tolerance induced by cold acclimation