The experiments of resistance of different super hybrid rice(SHR) combinations to sheath blight(ShB)(Rhizoctonia solani Kühn) and effect of nitrogen fertilizer(NF) dosage and fertilization methods on ShB occurren...The experiments of resistance of different super hybrid rice(SHR) combinations to sheath blight(ShB)(Rhizoctonia solani Kühn) and effect of nitrogen fertilizer(NF) dosage and fertilization methods on ShB occurrence were conducted in Hangzhou during 2005-2006.The results indicated that the resistance level of different SHR combinations to ShB were significantly different.For the same combination,the severity of ShB depends on the seeding and transplanting period.The disease index showed a positive correlation with the nitrogen dosage,but depended on resistance level of combination.The ShB severity of susceptible combination showed high positive correlation with NF dosage.At the flowering stage,there were no effect of nitrogen fertilization method on the occurrence of ShB,but the fertilization method showed significantly effect at dough stage.The occurrence of ShB was significantly affected by the supply rate of nitrogen at different rice growing stage.When the total NF supply was 165 kg per hectare,the occurrence of ShB with high NF rate(80%) at early stage(as basal and tillering fertilizer) and low rate(20%) at late stage(as panicle fertilizer) was more serious than that of low NF rate(60%) in early and high NF rate(40%) as panicle fertilizer.The result was the reverse of conventional viewpoint about that high NF supply at rice late growing stage might lead to severe occurrence of ShB.展开更多
The contents of chlorophyll, soluble sugars, soluble proteins and thiobarbitudc acid reaction substance （TBARS）, chlorophyll fluorescence parameters, net photosynthetic rate as well as the activities of superoxide d...The contents of chlorophyll, soluble sugars, soluble proteins and thiobarbitudc acid reaction substance （TBARS）, chlorophyll fluorescence parameters, net photosynthetic rate as well as the activities of superoxide dismutase （SOD） and peroxidase （POD） of flag leaves at the late growth stages were studied by using C Liangyou series of hybrid rice combinitions as material and Shanyou 63 as control. The C Liangyou series of hybrid rice combinations used in the experiment included C Liangyou 396, C Liangyou 87, C Liangyou 755 and C Liangyou 34, which all used C815S as male sterile line. The contents of chlorophyll, soluble sugars and soluble proteins in flag leaves of the C Liangyou series combinations at the late growth stages were higher than those of the control, whereas the TBARS content was lower than that of the control. The activities of SOD and POD were significantly higher than those of the control on the 7th day after heading, and then decreased slowly. ~bps, value and qp value of flag leaves decreased at the late growth stages, and these two parameters in flag leaves of the C Liangyou series combinations were higher than those of the control, while the qN value increased at the late growth stages and was lower than that of the control. The net photosynthetic rate of flag leaves at the late growth stage was higher compared with the control. These results suggest that slow senescence and strong photosynthetic capability in flag leaves at the late growth stages are the physiological basis of the C Liangyou series combinations.展开更多
文摘The experiments of resistance of different super hybrid rice(SHR) combinations to sheath blight(ShB)(Rhizoctonia solani Kühn) and effect of nitrogen fertilizer(NF) dosage and fertilization methods on ShB occurrence were conducted in Hangzhou during 2005-2006.The results indicated that the resistance level of different SHR combinations to ShB were significantly different.For the same combination,the severity of ShB depends on the seeding and transplanting period.The disease index showed a positive correlation with the nitrogen dosage,but depended on resistance level of combination.The ShB severity of susceptible combination showed high positive correlation with NF dosage.At the flowering stage,there were no effect of nitrogen fertilization method on the occurrence of ShB,but the fertilization method showed significantly effect at dough stage.The occurrence of ShB was significantly affected by the supply rate of nitrogen at different rice growing stage.When the total NF supply was 165 kg per hectare,the occurrence of ShB with high NF rate(80%) at early stage(as basal and tillering fertilizer) and low rate(20%) at late stage(as panicle fertilizer) was more serious than that of low NF rate(60%) in early and high NF rate(40%) as panicle fertilizer.The result was the reverse of conventional viewpoint about that high NF supply at rice late growing stage might lead to severe occurrence of ShB.
基金supported by the National High Technology Research and Development Project of China(Grant No.2006AA100101)the Agricultural Technological Results Transformation Fund,China(Grant Nos.2007GB2D200226 and 2008GB2D200227)
文摘The contents of chlorophyll, soluble sugars, soluble proteins and thiobarbitudc acid reaction substance （TBARS）, chlorophyll fluorescence parameters, net photosynthetic rate as well as the activities of superoxide dismutase （SOD） and peroxidase （POD） of flag leaves at the late growth stages were studied by using C Liangyou series of hybrid rice combinitions as material and Shanyou 63 as control. The C Liangyou series of hybrid rice combinations used in the experiment included C Liangyou 396, C Liangyou 87, C Liangyou 755 and C Liangyou 34, which all used C815S as male sterile line. The contents of chlorophyll, soluble sugars and soluble proteins in flag leaves of the C Liangyou series combinations at the late growth stages were higher than those of the control, whereas the TBARS content was lower than that of the control. The activities of SOD and POD were significantly higher than those of the control on the 7th day after heading, and then decreased slowly. ~bps, value and qp value of flag leaves decreased at the late growth stages, and these two parameters in flag leaves of the C Liangyou series combinations were higher than those of the control, while the qN value increased at the late growth stages and was lower than that of the control. The net photosynthetic rate of flag leaves at the late growth stage was higher compared with the control. These results suggest that slow senescence and strong photosynthetic capability in flag leaves at the late growth stages are the physiological basis of the C Liangyou series combinations.
