单／间作条件下氮肥水平对水稻总酚和类黄酮的影响

Effect of nitrogen levels on the changes of phenol and flavonoid contents under rice monocropping and intercropping system

采用田间试验研究了主栽杂交稻合系-41和优质糯稻黄壳糯间作条件下,高氮供应(N_(300))对易感病品种黄壳糯叶片中总酚和类黄酮含量、生物量、产量和稻瘟病发生的影响。结果表明,高氮供应(N_(300))显著降低了单作黄壳糯的生物量、产量及体内总酚和类黄酮含量,增加了稻瘟病发生的严重程度;而对间作黄壳糯产量和总酚含量无显著影响.对类黄酮含量的降低及稻瘟病发生的增加不及单作显著。在低氮供应(N_(180))下,合系-41与黄壳糯间作中黄亮糯较其单作明显提高了生物量和产量,提高了间作黄壳糯叶片中总酚和类黄酮含量,降低了稻瘟病发生。黄壳糯叶片中总酚和类黄酮含量与稻瘟病的发生呈负相关趋势。

Plant nitrogen（N） nutrition is important for plant metabolisms and its resistance to plant diseases. Two rice varieties with different resistance to rice blast, Huangkenuo（HKN） and Hexi-41 （HX41）, were used to investigate the effect of nitrogen fertilizer rates on the changes of phenol and flavonoid content in Huangkenuo rice plant and on its relationship to rice blast occurrence under rice monocropping and intercropping system. Results showed that high nitrogen level （N 300 kg/ha） reduced the biomass, yield, phenol and flavonoid contents in rice leaves, but increased the rice blast severity index, especially in monocropping Huangkenuo. Under rice intercropping treatment, high nitrogen rate had no significant effect on the yield and phenol content. However, the reduction of flavonoid content and increase of rice blast incidence was not as significant as in rice with the monocropping treatment. Under low nitrogen level, Hexi-41 and Huangkenuo intercropping increased the biomass, yield, phenol and flavonoid content and decreased the occurrence and severity of rice blast. Results also suggested that negative correlation existed between the contents of phenol and flavonoid in leaves, and the rice blast incidence.