{"created":"2022-01-27T02:43:44.730046+00:00","id":2002948,"links":{},"metadata":{"_buckets":{"deposit":"41d32238-c81f-48ea-a037-c1ca24eb9e1f"},"_deposit":{"id":"2002948","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"2002948"},"status":"published"},"_oai":{"id":"oai:u-ryukyu.repo.nii.ac.jp:02002948","sets":["1642837622505:1642837905044:1642837915094","1642838403551:1642838407312"]},"author_link":[],"item_1617186331708":{"attribute_name":"Title","attribute_value_mlt":[{"subitem_1551255647225":"パインアップルの CAM 型光合成に関する研究(農学科)","subitem_1551255648112":"ja"},{"subitem_1551255647225":"Studies on the CAM type photosynthesis of pineapple (Ananas comosus (L.) Merr.) plants (Department of Agriculture)","subitem_1551255648112":"en"}]},"item_1617186419668":{"attribute_name":"Creator","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"野瀬, 昭博","creatorNameLang":"ja"}]},{"creatorNames":[{"creatorName":"Nose, Akihiro","creatorNameLang":"en"}]}]},"item_1617186476635":{"attribute_name":"Access Rights","attribute_value_mlt":[{"subitem_1522299639480":"open access","subitem_1600958577026":"http://purl.org/coar/access_right/c_abf2"}]},"item_1617186626617":{"attribute_name":"Description","attribute_value_mlt":[{"subitem_description":"パインアップルは, 沖縄においてサトウキビにつぐ主幹作物のひとつである。当作物は, Crassulacean acid metabolism(CAM)植物に属する数少ない作物のひとつでもある。CAMとは, 高等植物に認められる3種類の炭素固定経路のひとつで, そのCO_2吸収が夜間に行なわれることなどから, 乾燥地適応型の炭素固定経路として知られている。当経路はC_4光合成の発見にともなって注目され始めたもので, 光合成経路として研究され始めたのは1970年代になってである。パインアップルも含めたCAM植物の物質生産機構については, 不明な点が多く残されている。CAM植物の生産性は一般に低い状態にあるが, パインアップルは通常の作物に匹敵するような高い生産性を示す植物である。本研究においては, 植物の物質生産において最も基本的な現象である, 光強度とパインアップルのCAM型光合成の関係についてとりあげた。この光強度とCAM型光合成の関係は, 以下に述べる研究の基本的な手段として組み入れた。次に, 日長とCAM型光合成の関係をとりあげ, 日長と日射量の両面から光環境の問題に検討を加えた。CAM型光合成は, 乾燥地適応型炭素獲得系と考えられることから, 土壌水分条件とCAM型光合成の関係について調査した。また, 近代農業技術の基本ともいうべき窒素栄養の問題をとりあげ, 根圏と葉内の窒素濃度がCAM型光合成に及ぼす影響を調査した。さらに, パインアップルのCAM型光合成における炭素フローとその基本的な制御機構について考察を加えたのち, パインアップルの物質生産の制御とその限界について論じた。最後に, 沖縄におけるパインアップル栽培について, 本研究の成果に基づき物質生産の観点から, 日射環境に重きをおいて検討を加えた。本研究で得られた結果は以下のとおりである。1.明期の光強度とCAM型光合成の関係 1)明期の平均光強度が上昇すると, 明期におけるCO_2放出速度が小さくなり, CO_2放出期間(phase 3)も短くなった。さらに, 明期の後半(phase 4)のCO_2吸収と, 暗期の(phase 1)のCO_2吸収速度も増大した。その結果, 1日のCO_2収支は, 明期の平均光強度が30∿40klxに達するまで, 光強度の上昇に伴い増大し, その後に定常値に達した。2)昼の日射量の増大は, 昼の終わりの葉内のリンゴ酸レベルを低くし, 夜の終わりのリンゴ酸レベルを高くするような様式で, リンゴ酸の日変化に影響を与えた。昼のリンゴ酸消失速度は, 100∿150cal/cm^2/5hの日射量の下で定常値に達した。夜のリンゴ酸蓄積量の増大は, 昼の日射量の上昇とともに生じた。しかし, 本研究の範囲では, 上限値を認めることはできなかった。昼のリンゴ酸消失速度が定常値に達した100∿150cal/cm^2/5hという日射量は, 平均20∿30klxの照度に対応し, CO_2交換の実験室内で得た飽和光強度とよく対応した値であった。","subitem_description_type":"Other"},{"subitem_description":"2.日長がCAM型光合成に及ぼす影響 パインアップルのCAM型CO_2交換は, 短日条件下で活発になった。短日条件下においては1日のCO_2収支が増大し, この増大はphase 1のCO_2収支の増大を通して行なわれた。長日条件下においては, phase 4でのCO_2吸収速度が活発になったが, 1日のCO_2収支は低下した。短日条件下におけるCO_2吸収の増大は, phase 1における葉内のCO_2固定能力の増大に由来していることが明らかになった。3.土壌水分がCAM型光合成に及ぼす影響 パインアップルは, 他の植物では萎凋を生じ枯死にいたる, 初期萎凋点や永久萎凋点の土壌水分下でも, 正のCO_2収支を示し, 極めて耐乾性にとんでいることが認められた。水利用効率を表す蒸散比も, 20∿150と小さく, 水利用効率の高さも明らかになった。しかし, 1日のCO_2収支の最大値は生長有効水分域(pF2∿3)で得られ, パインアップルの生育を旺盛にするためには, 適当な土壌水分の維持が必要であることが明らかになった。4.窒素栄養がCAM型光合成に及ぼす影響根圏の窒素濃度を277ppmに維持したとき, 1日のCO_2収支は最大となった。1日のCO_2収支は, 葉身の全窒素含量, 可溶性タンパク, クロロフィル含量と正の有意な相関を示していた。また, 1日のCO_2収支に占めるphase 1のCO_2収支割合, つまりCAM性も葉身の全窒素含量と正の有意な相関を示していた。窒素栄養の改善にともなうCO_2収支の増大は, phase 1のCO_2収支の改善を通して行なわれることが明らかになった。5.パインアップルの物質生産の制御とその限界 CO_2収支からみたパインアップルの物質生産の改善の方向は, そのCAM型炭素フローの特性から, phase 4のCO_2収支の増大を通して成されるべきであろうと推論された。CAM性を指標にして, 環境要因がパインアップルのCO_2収支に及ぼす影響の仕方を整理したところ, 仮定のとおりCAM性の低下を通してCO_2収支の改善にかかわる環境要因と, 逆にCAM性の強化を通してCO_2収支の改善にかかわる環境要因の2種類に, 環境要因の影響は類別できるものであった","subitem_description_type":"Other"},{"subitem_description":"Pineapple (Ananas comosus (L.) Merr.) is a main crop next to sugar cane in Okinawa. This plant is a rare crop belonging to crassulacean acid metabolism (CAM) plants. CAM is one of the three types of carbon fixing process observed in higher plants, and it is known to be favorable to arid area, since CO_2 exchange in CAM is done mainly at night. CAM is gaining an increasing interest with the discovery of C_4 photosynthesis, and studies on photosynthetic process were started in the 1970's. In CAM plants including pineapple, much has been left to be studied on the mechanism of matter production system. The productivity of CAM plants is generally low, but pineapple plants show a high a productivity as well as other usual crops do. In the present study, the authors first examined relationships between light intensity and CAM type photosynthesis, which is the most basic factor in plant matter production system. An approach adopting the above mentioned relationships was used for other experiments in this study. Secondly, relationships between day-length and CAM type photosynthesis were examined; and effects of light conditions were discussed from the view both of day-length and amunt of radiation. Thirdly, since CAM type photosynthesis is well known as a carbon-obtaining type tolerable to drought, relationships between soil moisture condition and CAM type photosynthesis were also examined. Forthly, the authors studied the effects of nitrogen nutrition which may be said to be the most important basis in agricultural technics. In other words, the effects of nitrogen concentration in culture solution and leaves on CAM type photosynthesis were examined. Fifthly, commenting on the carbon flow and the basic regulating mechanism of CAM type photosynthesis in pineapple plants, the authors discussed the possibility and limitation of matter production control in pineapple plants. On the base of the results obtanined in these studies, last of all, the growth of pineapple plants in Okinawa was analyzed in view of solar radiations for matter production.","subitem_description_type":"Other"},{"subitem_description":"Results obtained in the present studies are summarized as follows : 1. Relationships between light intensity in the light period and CAM type photosynthesis. 1) As average light intensity in the light period increased, both the CO_2 efflux rate and the CO_2 efflux duration (phase 3) decreased. In addition, CO_2 influx rate in both the later half of light period (phase 4) and the dark period (phase 1) increased. As a result of this process, daily CO_2 balance increased as the average light intensity in the light period increased up to 30 to 40 klx, and the balance attained a steady value under the average light intensities higher than 30 to 40 klx. 2) The effect of solar radiation on the daily variation in malate content in leaves was found as follows : The increase in solar radiation in the light period lowered the malate content in leaves in the end of the light period and it heightened the content in the end of the dark period. The disappearance rate of malate in the light period attained a steady value under the solar radiation of 100 to 150 cal/(cm)^2/5 hrs. The accumulation of malate in the dark period increased as solar radiation in the light period increased. In this study, however, the upper limit value of the accumulation was not observed. Solar radiation of 100 to 150 cal/(cm)^2/5 hrs in which malate disappearance rate reached a steady value corresponded to 20 to 30 klx of average light intensity. In other words, saturated soral radiation for malate disappearance in field experiments was almost equal to saturated average light intensity for CO_2 exchange obtained in laboratory experiments. 2. Effects of day-length on CAM type photosynthesis. It was found that CAM type CO_2 exchange in pineapple plants was activated under short day-length conditions. Under the short day-length, daily CO_2 balance increased, and these results were obtained by increasing CO_2 influx in phase 1. On the other","subitem_description_type":"Other"},{"subitem_description":"紀要論文","subitem_description_type":"Other"}]},"item_1617186643794":{"attribute_name":"Publisher","attribute_value_mlt":[{"subitem_1522300295150":"ja","subitem_1522300316516":"琉球大学農学部"}]},"item_1617186702042":{"attribute_name":"Language","attribute_value_mlt":[{"subitem_1551255818386":"jpn"}]},"item_1617186783814":{"attribute_name":"Identifier","attribute_value_mlt":[{"subitem_identifier_type":"HDL","subitem_identifier_uri":"http://hdl.handle.net/20.500.12000/3919"}]},"item_1617186920753":{"attribute_name":"Source Identifier","attribute_value_mlt":[{"subitem_1522646500366":"ISSN","subitem_1522646572813":"0370-4246"},{"subitem_1522646500366":"NCID","subitem_1522646572813":"AN00250548"}]},"item_1617186941041":{"attribute_name":"Source Title","attribute_value_mlt":[{"subitem_1522650068558":"ja","subitem_1522650091861":"琉球大学農学部学術報告"},{"subitem_1522650068558":"en","subitem_1522650091861":"The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus"}]},"item_1617187056579":{"attribute_name":"Bibliographic Information","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1986-12-05","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"33","bibliographicPageEnd":"70","bibliographicPageStart":"1"}]},"item_1617258105262":{"attribute_name":"Resource Type","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_1617265215918":{"attribute_name":"Version Type","attribute_value_mlt":[{"subitem_1522305645492":"VoR","subitem_1600292170262":"http://purl.org/coar/version/c_970fb48d4fbd8a85"}]},"item_1617605131499":{"attribute_name":"File","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_access","filename":"KJ00000162261.pdf","mimetype":"application/pdf","url":{"objectType":"fulltext","url":"https://u-ryukyu.repo.nii.ac.jp/record/2002948/files/KJ00000162261.pdf"},"version_id":"5ed6552e-3147-4307-b869-b9607832be44"}]},"item_title":"パインアップルの CAM 型光合成に関する研究(農学科)","item_type_id":"15","owner":"1","path":["1642837915094","1642838407312"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2008-02-14"},"publish_date":"2008-02-14","publish_status":"0","recid":"2002948","relation_version_is_last":true,"title":["パインアップルの CAM 型光合成に関する研究(農学科)"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-10-31T01:12:17.730268+00:00"}