Colchicine-Induced Polyploidy in pineapple (Ananas comosus L.) and Its Identification

Enhancing the horticultural and commercial value of Ananas comosus through polyploidy has great potential, as does meeting market demands. This study used different colchicine treatments, durations, and concentrations to induce polyploidy in pineapple somatic embryo callus. Consequently, a maximum polyploid induction rate of 40.00% was achieved in somatic embryogenic callus exposed to 0.1% colchicine for 20 days. Flow cytometry revealed 202 tetraploids among the regenerated plants analyzed. Polyploid plants, in contrast to diploid ones, are morphologically characterized by having thicker, heavier, wider, and shorter leaves, a larger leaf area, a darker color, a shorter overall height, thicker stems, and fewer, shorter leaf spines that are more irregularly distributed and differently shaped. In polyploids, the stomata were both larger and less numerous than in diploid plants, and the stomatal guard cells and leaf epidermal cells were larger too. The study revealed that polyploid plants exhibited much higher levels of chlorophyll and PEPC enzyme activity than the diploid control plants. Compared to diploid control plants, polyploid plants displayed enhanced resistance to salt and heat following treatment. Overall, this research outlined an efficient strategy for inducing polyploidy in pineapples, paving the way for future advancements in pineapple germplasm resources.