Enhanced growth of in vitro plantlets by cytokinin and pre-colchicine application in Phalaenopsisamabilis Blume protocorms

摘要

Polyploidy induction in Phalaenopsis amabilis is one of the important methods to develop broader diversity and expand the genotypes germplasm to include better characters. Producing a high percentage of polyploidy plants in P. amabilis culture raiseda question of how to produce better culture conditions when using protocorms as propagules. This study aimed to study P. amabilis protocorm growth on different cytokinin compositions before and after colchicine application and its effect on polyploidy. The study consisted of two experiments laid out in a completely randomized design investigating medium composition, with five levels (half strength Murashige-Skoog medium (% MS) + 15% of coconut water (CWJ; Vz MS + 0.51 mg L 1 BAP; Vz MS + 0.5 mg L i TDZ;Vz MS + 15% of CW + 0.51 mg L * BAP; % MS + 15% of CW + 0.5 mg L1 TDZ), with three replications. The result showed that cytokinin applied before colchicine application produced higher multiplication and putative polyploids number on Vz MS + 15% CW + 0.51 mg L1 BAP or Vz MS + 0.5 mg L1 TDZ medium. Screening of plantlets based on morphological characters allowed identification of normal and the putative polyploid plantlets. Chromosome number analysis of putative polyploid plantlets revealed that 20% of plantlets were polyploids.