Buletin Kebun Raya

1-4

Authors: Bian Tan

Jejaring (network) merupakan salah satu aspek penting dalam pengelolaan kebun raya, khususnya untuk mendukung implementasi fungsi kebun raya di bidang konservasi, penelitian, pendidikan lingkungan dan peragaan (display). Dalam the "Global Strategy for Plant Conservation" digarisbawahi tentang perlunya upaya memperkuat atau membangun jejaring kegiatan konservasi tumbuhan di tingkat nasional, regional maupun internasional. Beberapa contoh jejaring yang telah berhasil dikembangkan dikemukakan dalam tulisan ini. Dibangunnya kebun raya-kebun raya barn di berbagai daerah di Indonesia juga membutuhkan jejaring guna memperkuat komunikasi di antara kebun rays di Indonesia maupun dengan kebun rays di belahan bumi lainnya.

11-18

Authors: Irawati Irawati

Perkecambahan secara simbiotik pada anggrek Papilionanthe hookeriana dan Taeniophyllum obtusum dilakukan dengan menginokulasi jamur mikoriza dari kedua jenis anggrek ke biji dari anggrek yang sama dan anggrek yang berbeda. Jamur mikoriza diisolasi dan ditumbuhkan pada media isolasi jamur (FIM) dan perkecambahan dilakukan pada media Oat (OM). Empat jenis jamur diisolasi dari akar P. hookeriana, tetapi hanya dua yang tergolong mikoriza anggrek dan hanya satu jenis dari T. obtusum. Ketiga jenis jamur mikoriza tersebut adalah Ceratobasidium sp. yang penampilannya pada kultur murni agak berbeda. Perkecambahan secara simbiotik pada biji dan jamur mikoriza dari jenis yang sama menghasilkan respons yang sama. Akan tetapi inokulasi silang dari jamur mikoriza T. obtusum pada biji P. hookeriana ternyata memberi hasil yang lebih baik ditinjau dari persentase perkecambahan maupun jumlah rata-rata daun dan akarnya dan keduanya berbeda nyata pada taraf p = 0,05. Inokulasi silang sebaliknya tidak memberi hasil yang memuaskan. Bibit anggrek hasil perkecambahan secara simbiotik mempunyai peran penting dalam konservasinya di alam.

28-35

Authors: Didit Okta Pribadi

Agarwood is an important forest product due to its high economic value. However, the natural population of agarwood species has been decreasing rapidly because of over exploitation, therefore the international trade of the most important agarwood species (i.e. Aquilaria malaccensis) is restricted to just a small quota. This research was conducted in an attempt to provide basic information for the conservation of Aquilaria spp. by identifying the species spatial distribution and habitat characteristics and developing a linkage model between their abundance and habitat characteristics. Data were collected through a field survey at Kutai National Park in August 2006 with Aquilaria spp. as the target species. Data on the species localities were used to determine the species densities and the value of Distance Index of Dispersion. The ordinance levels between the target species and the surrounding other species were identified using a correspondence analysis, while the linkage model between the species abundance and habitat characteristics was established using an ordinal multinomial logit model. The results showed that Aquilaria spp. had a low density (0.01/ha) and were spatially distributed in a clump pattern. The abundance of Aquilaria species had a close association with soil texture, humidity and acidity, land elevation, air temperature and humidity, and light intensity. The abundance decreased with increasing the proportion of sandy clay loam content, soil humidity and acidity, land elevation, and light intensity. In contrast, the abundance increased with increasing sandy loam content, air temperature and air humidity. The existence of A. malaccensis was likely to associate with the existence of Goniothalamus sp., Macaranga sp., Vordia splendidissima, Lygopodium sp., and Stachyphrynium borneensis.

1-4

Authors: Mark Richardson

Building a new botanical garden is a valuable opportunity that should be implemented as well as possible. The new botanical garden should not simply a clone of the botanical gardens botanical gardens already established, but it should have its own uniqueness, for example in terms of collecting local plant species. There are several things to be considered that the development of new botanical gardens can have a clear direction and goals, including the founding mission of botanical gardens, involvement in conservation and interpretation, as well as the continuity of the existence of botanical gardens in the future.

15-24

Authors: Titien Ngatinem Praptosuwiryo, Dedy Darnaedi

Pengamatan sitologi dan kromosom somatik dilakukan pada 23 individu dari enam jenis tumbuhan paku genus Pteris (Pteridaceae) yang tumbuh meliar di Kebun Raya Bogor. Hasil pengamatan menunjukkan bahwa jumlah kromosom dasar pada keenam jenis Pteris yang diamati konsisten, yaitu x = 29. Ras diploid dengan 2n = 58 ditemukan pada P. biaurita, P. fauriei dan P. tripartita. Ras triploid dengan 2n = 87 terdapat pada P. fauriei dan P. multifida. Sedangkan ras tetraploid dengan 2n = 116 ditemukan pada P. ensiformis, P. tripartita, dan P. vittata. Informasi tentang P. tripartita ras diploid dan P. multifida ras triploid dilaporkan pertama kali untuk kawasan Malesia. Sedangkan informasi kromosom P. fauriei, P. multifida, dan P. vittata merupakan catatan sitologi baru untuk Pulau Jawa. Jenis-jenis yang memiliki lebih dari satu sitotipe diamati morfologinya dan dibahas secara singkat.

33-45

Authors: Yayan Wahyu Candra Kusuma, Dodo Dodo, Didik Widyatmoko

Indonesia possesses 386 plant species that are categorized as threatened. Dipterocarpaceae contributes the largest number, reaching 36.79 % of the total threatened plant species, followed by Myristicaceae (13.73 %) and Nepenthaceae (6.99%). Of these 386 threatened species, 29.27 % are critically endangered, 17.88% are endangered, and 52.85 % are vulnerable. Bogor Botanic Garden recently maintains 68 threathened plant species if Orchidaceae and Nepenthaceae members are not included on the list. Two species have been regarded as extinct, namely Dipterocarpus cinereus and Calamus spectabilis, while two other species are regarded as extinct in the wild (Mangifera casturi, and Mangifera rubropetala). This information can be useful for everyone for different purposes, especially for those who concern in the conservation of threatened plant species in Indonesia.

1-8

Authors: Sri Wahyuni

The characteristics and viability of agarwood (Aquilaria microcarpa Baill.) seed from the Bogor Botanic Garden's collection was investigated. Two batches of seed from intact mature fruit and dehisced mature fruit were tested for viability using germination and tetrazolium test methods. The result showed that although the tetrazolium test indicated a similar level of seed viability between the two batches (i.e. 85 — 93 %), the germination capacity of seed batch derived from dehisced fru,it was greatly reduced (i.e. 46 % total seed germination) compared to that derived from intact fruit (i.e. 97 % total seed germination). The decrease of seed germination capacity indicated the loss of seed vigour and was concomitant with the decrease of seed moisture content from 42.22 % to 24.79 % (fresh weight basis), thus underlining that the seed has a recalcitrant characteristic. Further observation on the seedling growth showed that there was an incidence of abnormal seedlings encountered in the seed batch from dehisced fruit. Detailed information on the morphological characteristics of the fruit, seed and seedling are presented in this paper.

16-22

Authors: Elly Kristiati, Winda Utami Putri

A study on seed germination of Kedawung was conducted in the Bogor Botanic Garden using seeds collected from living plant collection of the Purwodadi Botanic Garden. The purpose of the study was to reveal dormancy characteristics of the seed and to search for the effective method of enhancing seed germination of the species. Overall, seventeen treatments of scarification and application of chemical stimulants were tested. The result showed that scarification treatment is critical for promoting Kedawung seed germination. Nicking of the seed testa provided the best result with 80 % seed germination. Soaking the seeds in boiling water also helped the seed to germinate up to 62 %, especially when the time of soaking was appropriate. Meanwhile, the effect of chemical stimulants, i.e. KNO3 and GA3, was evident only if the application was preceded by a scarification treatment. Seed germination was enhanced with the application of either 500 ppm KNO3 or 1500 ppm GA3. These results suggest that the majority of kedawung seeds have physical dormancy (PY), but some may also have physiological dormancy (PD), and only a very little portion of them are evidently non-dormant seeds.

30-35

Authors: Elizabeth Handini

Grammatophyllum scriptum is a beautiful wild orchid that has an interesting economic value. However, the existence of this ornamental plant species is at risk because of irresponsible exploitation of the natural population and insufficient cultivation efforts. Currently, the Bogor Botanic Garden is developing a program of orchid propagation for enhancing the conservation of all potential orchid collections. The propagation of G. scriptum was basically carried out by culturing the seeds in a modified Hyponex or Vacin & Went medium, transplanting the plantlets into a more suitable medium and finally acclimatizing the resulting seedlings. A study was done to observe the effect of fertilizer application on the growth of acclimatized G. scriptum seedlings, as a means to improve the propagation technique of the species. The result showed that the application of 1 and 2 m1/I organic fertilizer (Sugih) as well as 1 and 2 g/I inorganic fertilizer (Hyponex) increased the seedling mortality, in which the application of 2 g/ml Hyponex fertilizer was being the most damaging treatment, leaving 12,5 % seedlings to survive. However, in terms of seedling growth, the application of 1 m1/I Sugih fertilizer was slightly beneficial to the formation of root and the elongation of stem of the acclimatized seedlings. It may be suggested, therefore, that G. scriptum seedlings require no (or very little amount of) supplementary fertilizer to boost their vegetative growth.

33-39

Authors: Sri Rahayu, Sutrisno Sutrisno

Seed characteristics and seed germination behaviour of Hoya parasitica Wall. (Asclepiadaceae) were observed to study the potentials of the seed for propagation and genetic conservation of the species. Seeds were collected from follicles produced by Hoya collection of Bogor Botanical Gardens. They are small, thin, plumed and showing a comose type. The weight of 100 seeds was 0.7 — 0.9 gram and the water content was 26 — 30% at the time of fruit opening. The water content decreased rapidly to 12.7% and 21.4% after one day of storage in a desiccator containing silica gel and in the open air, respectively. This is in accordance with the natural behaviour of the seed that is dispersed mainly by wind. In general, the seeds were easy to germinate (up to 99% total germination), both in the dark and under natural light, and there was no substantial dormancy encountered during seed germination. The seeds were able to germinate up to 60% while the water content was 3.8%, suggesting the possibilities of long-term storage of the seed for plant genetic resources conservation.

47-52

Authors: Nina Dwi Yulia, Juliarni Juliarni

Porophaloenopsis laycockii is an epiphytic orchid, endemic to Borneo. The orchid is not widely known since this orchid is rare and the trade of this species is restricted by the law. An observation was made to provide information on plant morphology and leaf anatomy of the species. Among various characters recorded, it was noted that the pencil-or-rat-tail-like leaf is about 5.66 mm in diameter and up to 1 m in length. It has relatively large stomata measuring 66.8 x 57.3 pm with low stomata density of 16.3 stomata per mm° of leaf surface area. These characters may influence its water management so that the plant should be grown and maintained in shade for better establishment.

60-66

Authors: Sri Rahayu, Ibnul Qoyim, Ninik Budhiastuti

Interaction between epiphyte Hoyo diversifolia Blume (Asclepiadaceae) and ants (Formicidae) was observed in Bogor Botanical Garden. Five species of ants were noted to be involved in the interaction, namely Acropygo sp., Pseudolosius sp., Oecophylla sp., Myrmoteros sp. and Euprenotepis sp. They exhibit a mutualism symbiotic interaction in an optional (facultative) manner. The ants take some advantages of floral and extra floral nectarines for food and apparently receive protection for their nests by seedlings of H. diversifolia. Meanwhile seed of H. diversifolia is carried out and dispersed by ants to some favourable sites to grow.