[Objective] The research aimed to study the effects of soluble substance concentration in cell and the scavenging activity of active oxygen radicals on the cold-tolerance physiology of Dongxiang wild rice.[Method] Dongxiang wild rice was used as materials to detect and compare the content of soluble sugar,free proline and soluble protein,POD activity,CAT activity,MDA content in the leaves in different growth periods.Using with control of two species of common cultivated rice Xieqingzao and Nongda 288.[Resul...
[Objective] The aim was to explore occurrence rules and forecast methods of cotton aphid in Poyang Lake Area in Jiujiang City to enrich prediction methods of cotton aphid in the area. [Method] The occurrence rules and influencing factors of cotton aphid in Pengze County in 28 years were analyzed with comparative analysis, correlation analysis and wavelet analysis. Furthermore, a long-term forecast model of occurrence grade of cotton aphid and a short-term forecast model of weather condi- tion suitability were established based on stepwise regression. In addition, a forecast test was conducted in cotton area in the north of Poyang Lake. [Result] The wavelet analysis showed that in recent 28 years, oscillating period at 4 years was significant for the occurrence grade of cotton aphid in the north of Poyang Lake, but insignifi- cant for cotton at seedling stage. The comparative and correlation analyses suggest- ed that occurrence of cotton aphid is of significant correlation with winter climate and weather conditions at middle and short periods. The prediction test indicated that long-term forecast model of occurrence grade of cotton aphid and short-term forecast model of weather condition suitability based on stepwise regression can be made use of in the areas with similar climate. [Conclusion] The research provides theoreti- cal references for prevention against cotton aphid in cotton-planting area.
