Buletin Kebun Raya

8-18

Authors: Diah Virsa Hastuti, Titien Ngatinem Praptosuwiryo, Nina Ratna Djuita

Cytological observations have been carried out by several researchers in South China, Japan, Ceylon, Hongkong, Himalaya and Java. The results from various regions showed that P. multifida had a fairly high genetic variation, namely diploid, triploid and tetraploid types. Therefore cytological and reproductive study on P. multifida from its geographical distribution areas need to be done. The objectives of this research were to observe the somatic chromosome number and reproductive type of P. multifida, and to recognize the relationship between morphological variation and its ploidy level as well as stomatal index. Plants were collected from several localities in Bogor. Ploidy level was determined by observing somatic chromosome number by using squash methods. Reproductive type was determined by counting spore number in each sporangium. Morphological characters examined were the stipe, lamina, pinnae, veins, and indusium. Observations of stomata and epidermis of leaves were done by making an incision paradermal leaf. Pteris multifida has two ploidy level and reproduction type, namely apogamous triploid (2n = 87) and sexual tetraploid (2n = 116). The two ploidy levels could not be distinguished based on morphological characteristics, but they can be differentiated by their epidermal cells number. Apogamous triploid has fewer number of epidermal cells, the sexual tetraploid has a greater number of epidermis.

29-36

Authors: Irawati Irawati

Amorphophallus titanium Becc. atau bunga bangkai memperbanyak diri secara alami melalui bijinya, tetapi karena pemasakan bunga betina dan jantan tidal bersamaan waktunya, maka jarang dijumpai buah/bijinya. Perbanyakan secara vegetatif diharapkan dapat dimanfaatkan untuk mempertahankan keragaman genetiknya. Eksplan dari tunas samping umbi Amorphophallus titanum yang berasal dari Lembah Anai, Sumatera Barat ditumbuhkan pada media Murashige-Skoog (MS) and Gamborg B5 dengan penambahan 0,1 mg/I NAA and 1 mg /IBA, dengan dan tanpa 1 mg/I 2,4-D atau 0,1 mg/I NAA dan 0,01 mg/I Kinetin. Penambahan arang aktif tidal< mempengaruhi pertumbuhan tunas dan daun. Selanjutnya kultur yang ditumbuhkan pada media MS dengan penambahan berbagai kadar trans-Cinnamic Acid (t-CA) dan Kinetin dapat menumbuhkan tunas tunggal ataupun ganda dari pucuknya. Kultur yang berasal dari kalus, akar atau potongan pelepah daun pertumbuhan tunasnya terbatas. Media terbaik untuk pertumbuhan tunas akar dan umbi pada media mengandung 0,3 mg/I NAA dan 0,03 mg/I Zeatin.

46-52

Authors: I Dewa Putu Darma, I Gede Tirta, I Made Ardaka

Pranajiwa (Euchresta horsfieldii (Lesch.) Benn) is a medicinal plant, which is growing wild and it is regarded as a rare plant. Currently, its existence in the wild increasingly threatened. Pengelengan Hill is one of the natural habitats of E. horsfieldii in Bali. Study of autecology aims to describe the ecology of E. horsfieldii in their natural habitat. E. horsfieldii was found abundant in plots II with 16.02% relative density, 9.68% of relative frequency and 25.69 of Important Value, grow clumped together with other plants (Idk 2.72).