There were many researches about the influence of micronutrient concentration toward growth of plants. However, there was no clear statement about the micronutrient level for growth of Phalaenopsis seedlings. Hence it was worth to investigate the optimum level of micronutrient for Phalaenopsis, an endangered orchid species. Using Phalaenopsis deliciosa as the subject, germinated seedlings were grown on defined culture media containing different MS micronutrient level. After 90 days with a subculture at day 45, fresh and dry weights of shoots and roots of the seedlings were measured. It was found that the optimum micronutrient level for P. deliciosa seedling growth was observed between 0.50× and 1.00× of MS micronutrient level. Higher micronutrient level caused roots and seedlings to deterioration except for a minority of seedling variants that grew exceptionally well, suggesting that high micronutrient level was selective for a small number of variants. The study demonstrated the importance of appropriate micronutrient level for supporting growth and development for wide range of genotypes in P. deliciosa. This micronutrient level may as well be optimum for other species under the genus Phalaenopsis and should be considered for maintaining genotype diversity in vitro.
Abstract:In a continuous effort to conserve Phalaenopsis species, the optimization of a previously designed defined medium was carried out to understand the effect of in vitro nitrogen nutrition on Phalaenopsis deliciosa Rchb.f. In order not to alter the nutrient balance, macronutrient level instead of solely Nitrogen (N) was adjusted. Seedlings were obtained from in vitro germination and randomly inoculated on media with various macronutrient levels (0.3×, 0.5×, 1×, 2× and 3×). Maximum shoot yield was observed at 2× macronutrient level. However, the best macronutrient level, which was 1× macronutrient level, resulted in the maximum root and seedling yield. This macronutrient level was applied on the subsequent experiment where seedlings were inoculated on media with various nitratenitrogen (NO 3 -N) to ammonium-nitrogen (NH 4 -N) ratios. Seedling yield was the highest at NO 3 -N/NH 4 -N ratio of 2.0 while Root to Shoot ratio (R/S) was the highest at NO 3 -N/NH 4 -N ratio of 5.0. NO 3 -N/NH 4 -N ratio significantly affected Water Content (WC) of seedlings and the response to NO 3 -N/NH 4 -N ratio was similar to R/S, correlating better root development to higher WC. By altering NO 3 -N/NH 4 -N ratio, plant quality in terms of yield and organ development could be encouraged.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.