THE METABOLISM OF PHOTOSYNTHATE CONTRIBUTING TO THE COOL DAMAGE TOLERANCE OF RICE PLANTS

1995 Fiscal Year Final Research Report Summary

• Project/Area Number: 06660013
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 作物学
• Research Institution: IWATE UNIVERSITY,FACULTY OF AGRICULTURE
• Principal Investigator: MURATA Takao Iwate Univ., Fac.Asgriculture, Professor, 農学部, 教授 (70241487)
• Project Period (FY): 1994 – 1995
• Keywords: cool damage / nitrogen application regime / carbohydrate metabolism / accumulation and translocation / sucrose / ripening stage / ソース・シンク関係 / 耐冷-多収稲作

Research Abstract

The effect of cool weather causes extreme damage on rice plant in the Northeast of Japann as in 1993. It is well known that the applying the heavy rate of nitrogen to obtain high yield of rice in normal year gives a negative effect in cool weather. Therefore, the application of reduced amount of nitrogen, especially at basal application is practically effective for the reduction of cool damage. This study was carried out to clarify the effect of different nitrogen application regime on the growth and yield as well as cool tolerance of rice cultivers. The cool damage is more severe under cloudy weather. This indicates that photosynthetic production and carbohydrate matabolism in rice plant importantly correlate to the cool damage. The metabolism of carbohydrate was studied at ripening stage.
In rice plant, the carbohydrate accumulated and translocated in leaves and stems was mainly sucrose but not starch and decreased rapidly at early ripening stage and accumulated again at late ripening stage.