1996 Fiscal Year Final Research Report Summary
Factors Affecting the Variation of Respiration Rate of Rice Plant During On togenesis
| Project/Area Number |
07660020
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
作物学
|
|---|
| Research Institution | Okayama University |
|---|
Principal Investigator |
SAITOH Kuniyuki Okayama Univ.Fac.of Agr.Associate Professor, 農学部, 助教授 (60153798)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KURODA Toshiro Okayama Univ.Fac.of Agr. Professor, 農学部, 教授 (10032301)
|
|---|
| Project Period (FY) |
1995 – 1996
|
| Keywords | Crop growth rate / Dark respiration / Growth efficiency / Rice / Temperature coefficient / 施肥レベル / 窒素濃度 |
|---|
| Research Abstract |
To clarify the effects of dark respiration on the dry matter production, respiration rates (Rr) in the different plant parts of rice plants, grown in the field, were measured for two years. The maximum rate of Rr in whole plant was recorded at the start of measurement (rooting stage) followed by a rapid decrease to the heading time and decreased gradually towards maturity. Rr in leaf blade and stem became nearly constant after the end of leaf expansion and during ripening period, respectively. This implies that Rr in matured plant organs shows a small variation. Although the temperature coefficient of Rr was 2.055 in average, it changed during growth season and among different organs. The growth efficiency, GE=DELTA W/ (DELTA W+Rp) (DELTAW ; increase of dry matter, Rp ; respiratory loss) maintained above 60% during earlier stage, and decreased gradually with growth, followed by the rapid decrease at the late ripening period. It means the increase in respiration is independent to dry-matter production. Although almost same amount of carbohydrates were respired, the GE at late ripening stage in 1992 (35%) with much sunshine hours was higher than that in 1991 (5%). This revealed that decrease in GE was mainly caused by the decrease in gross photosynthesis. Large amount of carbohydrates translocation also decreases GE of whole plant.
|
