Morpho-physiological disorders in in vitro culture of plants

The special conditions during in vitro culture results in the formation of plantlets of abnormal morphology, anatomy and physiology. Tissue culture conditions that promote rapid growth and multiplication of shoots often results in the formation of structurally and physiologically abnormal plants. They are often characterized by poor photosynthetic efficiency, malfunctioning of stomata and a marked decrease in epicuticular wax. Qualitatively also, the waxes present on the surface of the leaves of in vitro cultured plants may vary. The conditions under which most laboratories done tissue culture is high relative humidity and low light, no supplemental CO2, high sucrose and nutrient containing medium may contribute to a phenotype that cannot survive the environmental conditions when directly placed in a greenhouse or field. Understanding these abnormalities is a prerequisite to develop efficient transplantation protocols. The present review summaries the major abnormalities in in vitro culture of plants and also highlight the current and developing methods that are satisfactory for acclimatization of in vitro cultured plantlets. (c) 2006 Elsevier B.V. All rights reserved.