{"created":"2022-01-27T07:29:26.976531+00:00","id":2003281,"links":{},"metadata":{"_buckets":{"deposit":"01f9c150-2f3c-4c2b-8ccc-a139749a5c07"},"_deposit":{"id":"2003281","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"2003281"},"status":"published"},"_oai":{"id":"oai:u-ryukyu.repo.nii.ac.jp:02003281","sets":["1642837622505:1642837905044:1642837909989","1642838403551:1642838407312"]},"author_link":[],"item_1617186331708":{"attribute_name":"Title","attribute_value_mlt":[{"subitem_1551255647225":"イネの一代雑種利用に関する基礎的研究(農学科)","subitem_1551255648112":"ja"},{"subitem_1551255647225":"Basic studies on utilization of hybrid vigor in rice (Department of Agriculture)","subitem_1551255648112":"en"}]},"item_1617186419668":{"attribute_name":"Creator","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"村山, 盛一","creatorNameLang":"ja"}]},{"creatorNames":[{"creatorName":"Murayama, Seiichi","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":"イネの一代雑種利用に基礎的素材を提供するため, 本研究では経済的条件を含む種々の栽培条件で実験を行ない, ヘテロシスの程度およびその発現の様相について詳細な検討を行なうとともに, 組合せの方向性の問題についても若干の検討を行なった。その結果次のような成果が得られた。1)ヘテロシスの程度とその発現の様相について2・3の検討を行なうために, 1967年と1968年の2年にわたって実験を実施した結果, 収量において顕著なヘテロシスがみられた。'67年の実験では33組合せ中27組合せが高い親を凌駕し, うち8組合せでは有意差がみられた。最も組合せ能力の高い農林22号×荒木のF_1は中間親および高い親よりそれぞれ76%および50%増収であった。 '68年の実験では45組合せ中33組合せが高い親を凌駕し, うち6組合せは有意差を示した。最も組合せ能力の高い鈴成×Zenith CI 7787のF_1は中間親, 高い親および奨励品種を含む供試品種中の最高収量品種をそれぞれ84%, 64%および35%凌駕していた。収量構成要素の中では1穂粒数におけるヘテロシスが最も高く, 穂数および千粒重において低かった。収量におけるヘテロシスと各収量構成要素におけるヘテロシスとの関係を検討してみると, 1穂粒数におけるヘテロシスとの相関が最も高く, 相関係数は1%水準で有意であった。さらに各収量構成要素におけるヘテロシスの積との相関は極めて高く, 1%水準で有意な相関を示した。このことは収量におけるヘテロシスは各収量構成要素におけるヘテロシスの相加的または相乗的効果によってもたらされるが, とりわけ1穂粒数におけるヘテロシスの寄与が大きいことを示唆するものといえよう。親品種群でみられた形質間の遺伝的相関がF_1群で破れる傾向がみられた。とくに1穂粒数と穂数の相関は親品種群では負の高い相関(γ=-0.693)を示したのに対してF_1群ではかなり低く(γ=-0.211)なっていた。このことはF_1群において1穂粒数が相当増加しても穂数が減少しないか, あるいは逆に穂数が相当増加しても1穂粒数が減少しない新しい型の植物を生ずる可能性を示唆しており, 注目に値する現象と思われる。","subitem_description_type":"Other"},{"subitem_description":"2)栽培条件によって, ヘテロシスの発現がどのように変化するかを検討するために, 実用品種の経済的栽培条件の範囲に含まれる標肥普通植区, 標肥密植区, 多肥普通植区および多肥密植区の4条件で試験した結果, 一般に, ヘテロシス程度の高い組合せはどの栽培条件でも高いヘテロシスを示し, 逆にヘテロシス程度の低い組合せはどの栽培条件でも低かった。標肥区に対する多肥区の収量の増加率は, 親よりもF_1の方が高く, その傾向は標肥普通植区に対する多肥密植区の増加率においては一層強く現われていた。この事実から, 実用品種の経済的栽培条件下においては, ヘテロシスの発現はさらに顕著になることが予想される。また, 各形質のヘテロシスについて栽培条件間の相関係数を求めてみると千粒重以外の形質については相関は極めて高く, ほとんどが1%水準で有意であった。さらに, 平均収量について有意性の検定を行なうと, 鈴成×Zenith CI 7787のF_1は親品種および対照品種を通じて最高収量を示した品種よりも357g/m^2(42%)の増収を示し, 統計的に有意であった。3)播種期および移植期の移動とヘテロシスの発現との関係については, ヘテロシスの高い組合せは播種期および移植期の移動に関係なくヘテロシスが高く, また, 組合せ能力の低い組合せはどの場合でも低かった。さらに, 普通期植に対する早植の収量の増加率は, 多くの組合せにおいて親よりもF_1が高くなり, 早植の場合により一層ヘテロシス程度が高まる傾向がみられた。4)日本稲7品種間の二面交配実験を行なった結果, 一般および特定組合せ能力には有意差がみられたが, 正逆交雑間の差については千粒重の特定な正逆交雑間に有意差がみられただけで, 他の形質については有意でなかった。5)近縁係数とヘテロシスの間には多くの形質で負の相関がみられた。また, 日本品種間のF_1より両親のいずれかに外国品種を持つF_1において, ヘテロシス程度は一層顕著であった。6)如何なる栽培条件においても, 実用品種の収量を有意に凌ぐ組合せが得られ, しかも, 実用品種の経済的栽培条件においては, ヘテロシス程度がより顕著になる傾向が得られたことから, F_1種子を容易に大量に採種できる方法が開発されれば, イネの一代雑種利用の可能性は明るいと考えられる。","subitem_description_type":"Other"},{"subitem_description":"The author carried out the experiments to obtain the fundamental knowledges for the utilization of heterosis in rice F_1 hybrids under various field conditions including economical conditions. Result obtained are as follows. 1) Two field trials were conducted to obtain the knowledge of the degree and behavior of heterosis in 1967 and 1968. In 1967,the grain yield showed marked heterosis, that is, 27 of 33 cross combinations exceeded the higher parent, and 8 of them showed significant differences. Heterosis was the highest in the F_1 of Norin 22×Araki, exceeding the mid and the better-parental values by 76% and 57%, respectively. In 1968,33 F_1's of 45 cross combinations exceeded their higher parents, and 6 of them showed significant differences. The best F_1 Suzunari×Zenith CI 7787,exceeded the mid-parent, the better-parent and also the best cultivar used in the present experiment by 84%, 64% and 35%, respectively. The correlation coefficients of the heterosis obtained between the yield and each one of characters, such as the number of spikelets per panicle, the number of panicles per plant and the one thousand kernels weight were 0.757,0.619 and 0.462,respectively, in 1967. Almost all of those correlation coefficients were significant at the 1% level. Such tendency was also seen in 1968. Furthermore, the high correlation was seen between the heterosis in the yield and product of heterosis in each yield component characters. From these results, it was supposed that the heterosis in grain yield was brought about by the additive effect of the heterosis in yield component characters, especially by the heterosis in the number of spikelets per panicle. In the F_1 hybrids, number of panicles per plant and the number of spikelets per panicle did not show such strong negative correlation as observed among ordinary rice varieties. This fact duly suggests the possibility that some F_1 hybrids will become to be a entirely new plant type which definitely differs from their parental varieties. This may be taken as one of the causes by which the heterosis in grain yield will result.","subitem_description_type":"Other"},{"subitem_description":"2) A study was carried out to determine the degree of heterosis occured under 4 different cultural conditions which were economically adaptable for commercial varieties. The F_1 hybrid showing a high degree of heterosis under a certain cultural condition showed a higher degree of heterosis under any other cultural conditions as well. And besides, F_1 hybrid showing a low degree of heterosis under a certain cultural condition showed also a low heterosis under any other cultural conditions as well. As compared the grain yield of high fertilizer-level plot with that of standard fertilizer-level plot, percentage of increases were greater in F_1 hybrids than in parental varieties. To obtain more advanced knowledges of the heterosis phenomena with those characteristics, the author caluculated correlation coefficients with those heterosis value between each set of cultural conditions compared. In consequence, with those characteristics, such as the grain yield, the number of spikelets per panicle, the number of panicles per plant, and as the culm length, the degrees of heterosis observed under 4 different conditions were significantly correlated with one another. Furthermore, the significance tests for the mean grain yield under 4 different cultural conditions were carried out. The F_1 hybrids of Norin 22×Araki, Suzunari×Zenith CI 7787 significantly outyielded their parental varieties. Within the scope of the present experiment, the best cross combination was Suzunari×Zenith CI 7787 which significantly outyielded the highest yielding variety, Benisengoku, by 357g/m^2 (42%). 3) In the grain yield, the panicle weight and the number of spikelets per panicle, the degrees of heterosis obtained under three different cultural times, differing in the sowing and the transplanting times as well, were significantly correlated with one another. As compared the grain yield of","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/20.500.12000/4289"}]},"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":"1976-12-01","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"23","bibliographicPageEnd":"71","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":"KJ00000162553.pdf","mimetype":"application/pdf","url":{"objectType":"fulltext","url":"https://u-ryukyu.repo.nii.ac.jp/record/2003281/files/KJ00000162553.pdf"},"version_id":"cc2c6db5-fcc4-4fba-b70d-46c2f5a83858"}]},"item_title":"イネの一代雑種利用に関する基礎的研究(農学科)","item_type_id":"15","owner":"1","path":["1642837909989","1642838407312"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2008-02-14"},"publish_date":"2008-02-14","publish_status":"0","recid":"2003281","relation_version_is_last":true,"title":["イネの一代雑種利用に関する基礎的研究(農学科)"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-10-31T01:19:06.814670+00:00"}