@misc{oai:niigata-u.repo.nii.ac.jp:00005252,
 author = {Vidal, Takasaki  Alexis Kooichi},
 month = {Mar},
 note = {Zephyra elegansは,チリ北部海岸沿いの乾燥地域に自生するTecophilaceae科球根植物の一種であり,観賞植物として高い潜在的な利用価値がある.Z. elegansを花き園芸植物として利用するためには,効率的な繁殖と栽培技術の確立が不可欠である.しかし,自生地での成長は気象条件に大きく左右され,数年おきに萌芽して開花することや,人工栽培条件下でも種子発芽から開花まで通常5年以上かかるため,繁殖や栽培に関する研究が非常に少ない.これまで,Z.elegansの球根の休眠打破と開花についての研究結果が若干報告されているが,増殖に関する研究はほとんど行われていない.そこで,本研究はZ. elegansにおける効率的な増殖技術の確立を目的として,in vitroでの種子繁殖および栄養繁殖について研究を行った.In vitroでの種子繁殖に関しては,①発芽培地を検討した結果,寒天培地での種子発芽率が高かったが,MS培地に移植した後,実生の発育は停止した.一方,MS培地では,発芽率が59%であったが,実生は球根を形成した.②種子発芽に及ぼす光条件(暗黒,2000lux, 9500lux)およびpH(5.7, 6.7)の影響を検討した結果,9500luxの光条件では種子発芽率が97%で最も高かった.また,pH6.7では発芽が約2週間程度促進された.③球根の発達に及ぼすショ糖濃度(0～120g/L)およびpH(5.7, 6.7)の影響を検討した結果,75g/Lショ糖とpH6.7の条件が球根の発達に最も適していた.④球根の重さが順化後の活着率に影響を及ぼした.0.12g以下の球根は萌芽しなかったが,0.3g以上の球根はほぼすべて萌芽した.順化後2年目に開花が確認された.In vitroでの球根の重さは開花率にも影響し,0.15g以下の球根は開花しなかったが,0.4g以上のものはすべて開花した.組織培養による栄養繁殖においては,①花蕾,葉片,節間および節など外植体を,0.1mg/L BAおよび1mg/L NAAを含むMS培地に置床して培養した.カルスが下部の節間外植体から誘導された.形成されたカルスを1mg/L BAおよび0.1mg/L NAAを含むMS培地に移植したところ,少数のシュートが形成された.しかし,それらのシュートはガラス化状態となり,球根に発達しなかった.②芽を付けた球根の上の半分を1mg/L BAおよび0.1mg/L NAAを含むMS培地で培養した結果,外植体から複数のシュートが誘導された.さらに,これらのシュートから小球根が形成され,それらの小球根を植物成長調節物質無添加のMS培地に移植したところ,根の形成が観察された.本研究の結果より,in vitroでの種子培養によるZ. elegansの球根生産が可能であることが明らかとなった.また,種子発芽から開花までに要する期間が3年間に短縮された.一方,節間や球根外植体からシュートが誘導され,小球根を形成したことから,組織培養によるZ. elegansの栄養繁殖の可能性が示された.これらの結果は,Z. elegansの増殖に関する新しい知見を提供し,効率的な繁殖技術の確立に役立つものであると考えられる., Zephyra elegans is endemic specie belonging to the Tecophilaceae family, from the coastal desert in northern Chile. It has been described as a specie with high potential as an ornamental crop. One of the steps in order to have this new crop is the ability to commercially propagate this specie. This work focuses on solving this problem by the propagation of Zephyra elegans via in vitro culture of seeds and vegetal material. Greenhouse experiments suggest that Zephyra elegans should be treated as a winter flowering specie under greenhouse conditions. Under greenhouse conditions, commercial vegetative propagation of Zephyra elegans is not possible due to low propagation rate. Propagation by seeds takes time, and seeds will take more than 5 years in order to produce flowering comrs. As a solution for these propagation problems, in vitro protocols were created. There are very few works regarding propagation of Zephyra elegans. Experiments were performed in order to establish a method to reduce time from seed to flowering in Zephyra elegans. Nonetheless germination of seeds was highest in water-agar medium, due to plant necrosis occurring when plants were later transferred, MS medium, with a germination rate of 59%, was selected as the medium for germination. Increasing light intensity from dark conditions to 2000 lux to 9500 lux had a significant effect on increasing germination. Only under dark conditions increasing pH from 5.7 to 6.7 had a significant effect on increasing germination rate. With the objective of achieving the highest corm weight gain, 8 weeks old seedlings were cultured for 16 weeks in MS mediums with sucrose concentrations from 0 to 120g・L^-1 and pH 5.7 or 6.7. Maximum weight gain was observed in MS medium with 75g・L^-1 sucrose and pH 6.7. Corms were later transferred to pots and grown under greenhouse conditions. Corms weighing under 0.12g did not sprout, while all corms over 0.3g sprouted. All corms that were over 0.4g at the end of the in vitro culture stage flowered in the second year of greenhouse cultivation but those under 0.15g did not flower. Vegetative propagation was initially tested on flower buds, leaves, internodes and nodes. Callus was achieved with lower internodes in MS medium with 0.1mg・L^-1 BA and 1mg・L^-1 NAA. Sprouts were achieved when callus clusters were later transferred to MS medium with 1mg・L^-1 BA and 0.1mg・L^-1 NAA, but no survival was achieved, mainly due to vitrification. Vegetative propagation was possible via multiple shoot formation only when upper halves of corms were cultured for 16 weeks in MS basal semisolid medium with vitamins and 30g・L^-1 sucrose, supplemented with 1mg・L^-1 BA and 0.1mg・L^-1 Rooting was achieved when sprouts were transferred to hormone free MS medium. Time required from seeds to corms with flowering capability was reduced to 3 years by the use of the in vitro protocol described in this work. This may be helpful in genetic improvement programs as well as large scale propagation of homogenetic lines. Though in vitro vegetative propagation protocol achieved in this work does not allow for conservation of the mother plant, it may be useful in commercial production and conservation of genetic material. Future experiments are needed in order to perform acclimation and greenhouse flowering stages for vegetative propagation generated plantlets, as with plantlets from seed experiments. Mass vegetative propagation was achieved for the first time in Zephyra elegans., 新潟大学大学院自然科学研究科, 平成23年3月23日, 新大院博（学）甲第196号, 新大院博（学）甲第196号},
 title = {Propagation of Zephyra elegans D.Don by the Use of In Vitro Techniques},
 year = {2011}
}