Preliminary Study On Photosynthetic Characters Of Resistant (Tolerant) Sugarbeet To Rhizomania

The relationship between some physiological index of photosynthesis of resistant (tolerant) or sensitive sugarbeet varieties to Rhizomania and the resistance to Rhizomania in sugarbeet were studied by the method of comparative physiology. The results showed: (1)The chloroplast content, activity of Hill reaction and photosynthetic rate in resistant varieties were prominently higher than sensitive ones in both diseased-soil and non-diseased-soil and could be used to select resistant variety to Rhizomania. (2)Root yield, sugar content and sugar yield of resistant varieties were also higher than sensitive ones both diseased-soil and non-diseased-soil. The photosynthetic rate had positive correlation with yield and sugar content, and the correlation was remarkable in later period. On sick soil, the photosynthetic rate had also positive correlation with sugar content in seedling stage and was significant.(3)WUE of resistant varieties were showed higher content than sensitive varieties unless seedling stage.It could be used to select breed resistant to Rhizomania in special period. (4)On sick and sickless soil , intercellular CO2 concentration of resistant varieties were always lower than sensitive, however, their stomatal conductance were opposite. The study had significant meaning on theory and practice. It provided the theoretical basis references for judging and selecting a new sugarbeet-variety resistant to Rhizomania.