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Growth of Limonium spp. ´Misty Blue´ under in vitro autotrophic and mixotrophic culture conditions as affected by initial phosphrous (P) concentration in the medium was studied. Growth was most effectively promoted under autotrophic conditions, in which no organic matetzals were added to the medium, and PPF, CO₂ level, and number of air exchanges per hour of the culture vessel were elevated. At the end of culture, medium pH in autotrophic culture was 5.85, which was similar to the initial pH of 5.70, while that in mixotrophic culture was 5.29. Medium EC at the end of mixotrophic culture was 1.60 mS·㎝^(-1), which was higher than that in autotrophic culture, suggesting less uptake of nutrients by plantlets. Plantlet growth under autotrophic culture conditions was further enhanced when additional P was supplemented to MS basal medium. Among different P levels examined, initial concentration of 2.665 meq·L^(-1) produced plantlets with the greatest number of leaves, leaf area, fresh weight, length of the longest root, and leaf chlorophyll concentration. However, plantlets with the greatest height, dry weight and percent dry matter were produced with the initial P concentration of 4.080 meq·L^(-1). Under mixotrophic culture conditions, the positive effect of P supplementation was not obvious. MS basal medium which has 1.250 meq·L^(-1) P, or MS basal medium with a total 4.080 meq·L^(-1) P, however, gave the best overall growth. Excessive P level in both autotrophic and mixotrophic culture was detrimental to plantlet growth.
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