Study on pollen viability of Rubus spp. At Cibodas Botanic Gardens

Rubus spp. known as raspberries is a belonging genus of the Rosaceae. Rubus have a wide range of medicinal and nutritional property, but it is rarely cultivated for commercial need in Indonesia. It is due to a lack of information about Indonesian Rubus. The information about flowering and pollen viability will contribute to its cultivation efforts and increase the success rate of hybridization. The aim of this study was to determine the pollen viability of Rubus spp. collection of Cibodas Botanic Garden. Ten species of Rubus spp., which are 8 species of wild type and 2 species commercials, were tested for pollen viability. The pollen viability test was observed by the in vitro germination and staining method. The result showed that the viability of pollen grains ranged from 59.68 % to 98.12%. Rubus linneatus showed the fastest and highest pollen germination in 1-hour germinated. On the other hand, the slowest of pollen germination was Blackberry, with 1.7 % after 1 hour germinated. There was a positive correlation among germination, pollen viability, and pollen tube lengh.