Effects ofin vitroculture types on regeneration and acclimatization of yellow poplar (Liriodendron tulipiferaL.) from somatic embryos

Abstract

We compared germination efficiency for somatic embryos (SE) of Liriodendron tulipifera using semi-solid (SS), temporary immersion bioreactors (TIB), and continuous immersion bioreactors (CIB) to produce vigorous plants. The bioreactors were designed to be immersed in liquid media with plantlets with an adjustable immersion time. TIB and CIB improved germination rates up to 80.86% and 95.21%, respectively, however, CIB produced more hyperhydric plantlets than TIB. The height of plantlets in TIB was significantly higher than for those in CIB. Fresh weights of plantlets grown in CIB of were significantly lower than for those grown in TIB. The lowest chlorophyll concentration was found in in vitro plantlets from CIB. We examined abnormally developed leaves, stems, and apical zones of in vitro plantlets that were produced in CIB. Among the three types, SS showed the highest stomatal density and the shortest stomatal length in in vitro plantlets. After acclimatization, plants from CIB exhibited the lowest values in biomass, such as height, root collar diameter, leaf fresh weight, leaf length, leaf width, petiole length, petiole diameter, and leaf area. Photosynthesis and transpiration rates of ex vitro plants were not significantly different among the three culture types, but stomatal conductance was higher in TIB than in the SS and CIB. Therefore, the results suggest that TIB is the preferable bioreactor to improve in vitro plantlet regeneration of L. tulipifera. TIB-originated plants showed higher growth rate than SS and CIB after transferring to soil.

In Vitro Propagation of Rheophytic Orchid, Epipactis flava Seidenf.—A Comparison of Semi-Solid, Continuous Immersion and Temporary Immersion Systems

“…Prior reports revealed that different culture systems resulted in diverse growth and morphogenesis of cultured plants [11,14,22]. The highest ratio of normal plantlets was obtained in TIS treatment, whereas SSS and CIS methods exhibited higher plant-abnormality rate [18,23]. The SSS medium possibly provided less nutrient absorption than TIS and CIS [16], while CIS frequently induced abnormality and necrosis symptoms resulting from permanent immersion [24].…”

“…Advances in in vitro culture techniques such as TIS have recently been developed to improve mass propagation efficiency that was difficult to accomplish using conventional propagation systems such as SSS or CIS [17]. TIS mass propagation success has previously been reported for various plant species [18,19]-including orchids [11,20,21]. Prior reports revealed that different culture systems resulted in diverse growth and morphogenesis of cultured plants [11,14,22].…”

“…By contrast, morphological plantlet disorders were mostly derived from SSS and CIS. Many previous reports indicated that plantlets from TIS had greater growth, with rapid adaptation after exposure to ex vitro conditions than SSS and CIS derived plant [18,33]. This might be because TIS enhanced stomatal functioning and improved photosynthesis and transpiration [31,34].…”