光独立栄養条件および光混合栄養条件下で培養されたアルファルファ小植物体の生長および光合成速度

Abstract

In order to clarify the differences in growth characteristics between photoautotrophically and photomixotrophically grown plantlets, growth rate and net photosynthetic rate (PN) of alfalfa plantlets were measured. These plantlets were cultured in vitro on hormone-free Ms medium with different sucrose concentrations of 0, 1 and 3% in aerated vessels.Chlorophyll content per unit leaf area of plantlets with 1% sucrose was the greatest (61±2 μg⋅cm-2) at all times (7, 14 and 21 days after treatments) . Leaf area with 1% sucrose was 1.4 times greater than that with 0% 14 and 21 days after treatments. But that with 3% was lower.PN values per unit leaf area with 0 and 100 sucrose were similar to each other. While those with 3% sucrose did not increase from the start of treatments and much lower than those with 0%.These results suggest that photomixotrophic condition with optimal concentration of sucrose accelerate the growth of photosynthetic organs and enable alfalfa plantlets to acquire photosynthetic products, at least, as much as those acquired under photoautotrophic condition.