Meiotic Behavior, Capsule Setting and Seed Germination of Diploid and Polyploid Phalaenopsis amabilis

Ploidy levels, morphological traits in different ploidies, meiotic behavior and capsule settings in the interploid crossings in three cultivars of Phalaenopsis amabilis were investigated. Diploid, triploid and tetraploid cultivars were identified by flow cytometry. The stomatal density per unit area of the abaxial leaf surfaces was lower and stomatal sizes were bigger in the tetraploid than in the diploid and triploid cultivars. Almost all pollen mother cells (PMCs) of the diploid cultivar were divided into tetrads, whereas the triploid and tetraploid plants had numerous PMCs which were divided irregularly into sporads with a varying number of micronuclei. When the triploid plant was used as a female or male parent, the germination rate of the hybrids was low. It was shown that the size and density of stomata can be used as rapid techniques for identification of ploidy levels of P. amabilis, and the percentage of normal tetrads of PMCs can be a criterion for the selection of pollen donor plants