Fertilizing ability of cryopreserved pollinia of Luisia macrantha, an endemic orchid of Western Ghats

Abstract

A successful protocol for long-term preservation of pollinia of Luisia macrantha Blatter and McCann., an endemic and endangered orchid of Western Ghats has been devised through different pollen cryopreservation methods and by confirming fertilizing ability. Pollinia subjected to 0-30 min dehydration at 27 +/- 67 percent in desiccated controls and 54 percent in LN treated samples. The treated pollinia retained fertilizing ability, giving 100 percent fruit set upon sib-mating. Pollinia dried under charged silica gel for 120 min gave 51 - 52 percent pollen germination, in LN treated and desiccated control samples. Exposure to vitrification solution (PVS2) was optimized at 10 min to achieve 57 percent and 56 percent germination in control and LN treated samples, respectively. These pollinia exhibited 51 percent pollen germination after 668 days storage in LN. Cryopreserved pollinia (10 min PVS2) used for hybridization with Vanda tessellata gave 87 percent fruit set and 21 percent viable seeds. The viable seeds germinated and developed into healthy seedlings. Thus cryopreservation has been proved useful for the successful storage of L. macrantha germplasm and their utilization in breeding.