Morphological and physiological characterization of two new pineapple somaclones derived from <Emphasis Type="Italic">in vitro</Emphasis> culture

We previously reported a partial agricultural and amplified fragment length polymorphism (AFLP) characterization of two new pineapple somaclones (P3R5 and Dwarf) derived from in vitro culture of the donor cv. Red Spanish Pinar. Both somaclonal variants showed different AFLP banding patterns compared to the donor cultivar, although they were separated by less than 0.09 U of genetic distance. The present report shows data of various indicators of morphology and physiology of P3R5 and Dwarf D leaves. The stoma diameter, number of stomata per square millimiter, diameter of leaf vascular tissue, thickness of the leaf aquiferous parenchyma, and thickness of the leaf photosynthetic parenchyma were measured. The photosynthetic rate, the transpiration rate, the water use efficiency, the internal leaf CO₂ concentration, and the chlorophyll pigment contents were recorded as well. Between the somaclonal variant P3R5 and the donor genotype, statistically significant differences were recorded in all indicators with the exception of the stoma diameter and the photosynthetic rate. Comparing the somaclonal variant Dwarf and the cv. Red Spanish Pinar (donor), statistically significant differences were also recorded in all parameters except in the stoma diameter and in the transpiration rate. This investigation was performed to demonstrate that small changes in the pineapple DNA may result in relevant phenotypic modifications.