[Objective] This study aimed to explore the effects of water and fertilizer regulation on the function of leaves in the filling stage. [Method] Six hybrid rice vari- eties including prematurely aged types and non-prem...[Objective] This study aimed to explore the effects of water and fertilizer regulation on the function of leaves in the filling stage. [Method] Six hybrid rice vari- eties including prematurely aged types and non-prematurely aged ones were selected as experimental materials. Limiting water treatment （with soil water potential of about -25 kpa） and increasing nitrogen treatment （additional 10% of granular nitrogen fertiliz- er in addition to limiting water treatment） were applied after heading to analyse the rates of aging and physiological responses of anti-aging in different hybrid rice vari- eties under water deficit and increased nitrogen conditions taking regular water and fertilizer as control. [Result] The results showed that water deficit accelerated the leaf senescence, and prematurely aged types-＇Zhongyou838＇, ＇Tianyou998＇ and ＇Long- ping601 ＇-were more markedly affected by water deficit, of which the rates of chloro- phyll degradation were 6%-8% higher compared to that in another three hybrids. In- creasing nitrogen treatment raised chlorophyll content and slowed down its degrada- tion. Water deficit caused the increase of abscisic acid （ABA） content to obviously varying degrees in leaves of six hybried rice varieties. Responses of ABA content in six hybried rice varieties to increased nitrogen fertilizer were not consistent. Except in ＇Zhongyou838＇, ABA content in the other five hybrids had varying degrees of in- crease. The responses of the activity of antioxidant enzymes in different hybried rice varieties were inconsistent. In response to increased nitrogen fertilizer in combination with water deficit, the activity of each antioxidant enzyme changed differently. Water deficit enhanced the accumulation of malondialdehyde （MDA） in leaves of each hybrid rice. The correlation analysis showed that chlorophyll content was extremely signifi- cantly positively correlated to the resistance of each antioxidant enzyme; SOD activity in leaves also positively related to ABA content. [Conclusion] The rate of leaf aging, physiological activity of anti-aging, and response to water deficit varied in different hy- bried rice varieties. The activity of antioxidant enzymes were not all induced to improve by ABA. SOD activity can be an indicator of resistance to stress. Increasing nitrogen ap- plication significantly postponed leave senescence in the late growth stage of rice.展开更多
基金Supported by the National Natural Science Foundation of China(30860137)the Research Fund of Department of Education of Jiangxi Province(GJJ09168)~~
文摘[Objective] This study aimed to explore the effects of water and fertilizer regulation on the function of leaves in the filling stage. [Method] Six hybrid rice vari- eties including prematurely aged types and non-prematurely aged ones were selected as experimental materials. Limiting water treatment （with soil water potential of about -25 kpa） and increasing nitrogen treatment （additional 10% of granular nitrogen fertiliz- er in addition to limiting water treatment） were applied after heading to analyse the rates of aging and physiological responses of anti-aging in different hybrid rice vari- eties under water deficit and increased nitrogen conditions taking regular water and fertilizer as control. [Result] The results showed that water deficit accelerated the leaf senescence, and prematurely aged types-＇Zhongyou838＇, ＇Tianyou998＇ and ＇Long- ping601 ＇-were more markedly affected by water deficit, of which the rates of chloro- phyll degradation were 6%-8% higher compared to that in another three hybrids. In- creasing nitrogen treatment raised chlorophyll content and slowed down its degrada- tion. Water deficit caused the increase of abscisic acid （ABA） content to obviously varying degrees in leaves of six hybried rice varieties. Responses of ABA content in six hybried rice varieties to increased nitrogen fertilizer were not consistent. Except in ＇Zhongyou838＇, ABA content in the other five hybrids had varying degrees of in- crease. The responses of the activity of antioxidant enzymes in different hybried rice varieties were inconsistent. In response to increased nitrogen fertilizer in combination with water deficit, the activity of each antioxidant enzyme changed differently. Water deficit enhanced the accumulation of malondialdehyde （MDA） in leaves of each hybrid rice. The correlation analysis showed that chlorophyll content was extremely signifi- cantly positively correlated to the resistance of each antioxidant enzyme; SOD activity in leaves also positively related to ABA content. [Conclusion] The rate of leaf aging, physiological activity of anti-aging, and response to water deficit varied in different hy- bried rice varieties. The activity of antioxidant enzymes were not all induced to improve by ABA. SOD activity can be an indicator of resistance to stress. Increasing nitrogen ap- plication significantly postponed leave senescence in the late growth stage of rice.
