1991 Fiscal Year Final Research Report Summary
Studies on the annuality and perenniality in the genus Oryza
| Project/Area Number |
02454038
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
作物
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| Research Institution | Chiba University |
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Principal Investigator |
TAKASAKI Yasuo Chiba University, Faculty of Horticulture, Professor, 園芸学部, 教授 (30009328)
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| Co-Investigator(Kenkyū-buntansha) |
ISODA Akihiro Chiba University, Faculty of Horticulture, Research Assist., 園芸学部, 助手 (10183740)
NOJIMA Hiroshi Chiba University, Faculty of Horticulture, Lecturer, 園芸学部, 講師 (30009550)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Oryza sativa / Oryza glaberrima / Annual / Perennial / Leaf senescence / ^<13>C / Translocation / Chlorophyll content |
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| Research Abstract |
The purpose of this study is to clarify the physiological characteristics of annuals and perennials in the genus Oryza. W492, a strain of O. glaberrima, and Norin no. 22, a cultivar of O. sativa were compared to ascertain (i) the accumulation pattern of dry matter into panicles (ii) leaf senescence and (iii) translocation of assimilates into plant parts. We consider W492 to be annual because it dies within one year even under a 24hr photoperiod-12hr/12hr temperature of 25/20ﾟC and we consider Norin no. 22 to be perennial because it continues growing mare than one year under natural day length-day/night temperature of 25/20ﾟC.
The dry matter accumulation pattern in panicles was almost the same in both strains, though W492 was a little faster than Norin no. 22 at the early stage of ripenning. However, this was not in consonance with the results of the preliminary trial which showed that the accumulation of dry matter in panicles was much more faster in W492 than in Koshihikari (a cultivar of O. sativa). More experiments will be needed to confirm this fact.
Leaf senescence indicated by chlorophyll content, SPAD values of a chlorophyll metre reading and nitrogen content was faster in W492 than in Norin no. 22. The difference in senescence between annual and perennial was very clear.
The rate of ^<13>C distributed to the various plant parts showed that the translocation of assimilates to panicles continued till later stage in Norin no. 22 than in W492. As the leaf area per plant of W492 decreased more rapidly than Norin no. 22, assimilating capacity per plant of W492 declined more sharply than Norin no. 22. Therefore, while Norin no. 22 was able to reserve some assimilates in the stubble during ripenning stage, W492 was not able to do so.
More detailed experiments are necessary to generalize the results on annuality and perenniality.
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