CURRENT TRENDS OF PHALAENOPSIS ORCHID BREEDING AND STUDY ON POLLEN STORAGE

Abstract

Phalaenopsis is the most popular potted orchid at commercial scale production in many countries. The export value of Phalaenopsis in Taiwan was approximately US$120 million during 2012. A decade ago, after official approval of plant variety rights for Phalaenopsis orchids, there were only 10 applications at the beginning; however, it increased to 151 in 2012. Many new cultivars were selected and micropropagated in quantity and sent to foreign countries for commercial cultivation tests. This indicates traditional cross hybridization still remains the priority for the Taiwan orchid industry to contribute novel hybrids for both domestic and international markets. Superior parents sometimes are not available for the breeding purpose. One alternative to keep the germplasm available is long-term storage of pollen so that it is available for use at any time. The objective of this study was to examine the storage ability of P. Little Gem Stripes pollinia at four temperature regimes. After storage for certain periods, pollinia was cultured on pollen germination medium with 5% sucrose for seven days to evaluate pollen tube growth and viability by Alexander and TTC stains, as well as hand pollination to a female parent. The results indicated that pollen lost germination ability when stored for 4-8 weeks at room temperature evaluated by three methods. After low temperature storage of pollen for up to 24 months, they still showed viability, although their germination rate decreased gradually. Pollinia stored at -20°C for 24 weeks showed higher germination rate than at 4 or -80°C. Pollinia stored at all three low temperatures were successfully pollinated to the female parent.