Effects Of Physiological Indexes On Different Seedling Methods And Heeling-in Seedling Age Of Tobacco

Different seedling methods and heeling-in seedling age regulated the growth,carbon and nitrogen metabolism and antioxidant system enzyme activity of plants.In order to optimize the winter seedling methods of tobacco-rice rotation areas of Hunan province,the effect of 4 seedling methods?ordinary floating seedling,two-stage seedling,seedling nursing in shallow water and two-stage seedling nursing in shallow water?and 3 heeling-in seedling age on the growth in field stage,carbon and nitrogen metabolism and antioxidant system enzyme activity of tobacco plants was investigated.Main results were as follows:1.Plants in and two-stage seedling nursing in shallow water had better performance than those in two-stage seedling,ordinary floating seedling and seedling nursing in shallow water in agronomic traits,including plants height,stem girth,leaf length and width,and metabolic indexes,including reducing sugar,total sugar,amino acids,protein and nitrate reductase,in the whole growth stage,and physiological indexes including chlorophyll a,chlorophyll b,carotenoid and root activity in cluster stage,vigorous growing period and topping period.Among them,Plants in two-stage seedling nursing in shallow water chlorophyll a and nitrate reductase were 1.62mg/g and 123.05(?g·g^-1·h^-1),respectively,which were 11.7%and 36.9%higher than those in ordinary floating seedling.Plants heeling-in transplanted in 5 leaves and 1 hearts seedling age had better performance than those in 3 leaves and 1 hearts and 4 leaves and 1 hearts seedling age in agronomic traits,including plants height,stem girth,leaf length and width,and metabolic indexes,including reducing sugar,total sugar,amino acids,protein and nitrate reductase,in the whole growth stage,and physiological indexes including chlorophyll a,chlorophyll b,carotenoid and root activity in cluster stage,vigorous growing period and topping period,which indicated that,tobacco plants heeling-in transplanted in 5 leaves and 1 hearts seedling age by two-stage seedling had optimization in adaptation to new soil invironment after transplanting,and had shorter rejuvenation period of plants.2.The activity of SOD,POD,CAT,APX and GR of tobacco plants,raised by two-stage seedling nursing in shallow water,was higher than those in two-stage seedling,ordinary floating seedling and seedling nursing in shallow water in field stage.The activity of SOD,POD,CAT,APX and GR of tobacco plants,heeling-in transplanted in 5 leaves and 1 hearts seedling age,was higher than those in 3 leaves and 1 hearts and 4 leaves and 1 hearts seedling age in field stage,which indicated that,the enhancement of antioxidant enzymes activity helped improve anti-stress ability in field stage of tobacco plants and guaranteed the production of tobacco leaves.3.Plants raised by two-stage seedling nursing in shallow water,had higher contents of reducing sugar,total sugar,nicotine and potassium than those in two-stage seedling,ordinary floating seedling and seedling nursing in shallow water,which helped improved the chemical quality of tobacco leaves.