Effects of CO_2 enrichment on growth and C, N accumulation of tomato seedlings under various strengths of nutrient supply

摘要

The objective of this study was to study the effects of elevated CO_2 on tomato growth and N, C accumulation in seedling stage under various strengths of nutrient supply. Tomato was raised in nutrient solution for 46 days. The CO_2 concentration in the growth chambers were set at 360 μl·l~(-1) and 720 μl·l~(-1) respectively. The results showed that the elevated CO_2 significantly promoted the growth of the tomato. The effect of CO_2 enrichment strongly depended on the strength of nutrient supply. High nutrient concentration in solution enhanced the positive effect of CO_2 enrichment. Enrichment of CO_2 produced no significant difference in C and N content, and produced a larger C and N accumulation amount in various parts of the tomato plants. The ratio of C to N in the roots, stems and leaves were significantly decreased by CO_2 enrichment. But under the same CO_2 level, the ratio of C to N in the tissues decreased as strength of nutrient solution was increased.