Judul: Flowering Phenology and Fruit Development of Diospyros maritima Blume in Bogor Botanical Garden
Abstrak: Diospyros maritima Blume is a dioecious plant, in native habitats male plants are more difficult to find than female plants, which affects plant reproduction. Conservation planning and plant breeding are needed to overcome this problem. It is important to have information about the phenology of D. maritima Blume in order to preserve and breed the plants. The study aimed to analyze the phenology of flower and fruit formation of D. maritima Blume, such as the phase and time of the flowering period, environmental factors that affect flowering, and morphological changes in flower and fruit development. Three female and three male D. maritima Blume trees from the Bogor Botanical Garden's collection that were originally from Halmahera, North Maluku, were observed. The initiation phase, small bud phase, large bud phase, anthesis phase (flower bloom), fruit development phase, and fruit ripening phase all occur during one period of flower and fruit development, which lasts for around 10 months (277–292 days). The microclimate of air humidity affects the timing and size of the flower development phase, while light intensity affects the timing and size of the fruit ripening phase. Morphological changes are found in each phase, such as changes in the texture, color, and shape of the plant's flower and fruit., Diospyros maritima Blume merupakan tumbuhan berumah dua. Pada habitat aslinya tumbuhan jantan lebih sulit dijumpai dibandingkan tumbuhan betina, sehingga memengaruhi reproduksi tumbuhan. Perencanaan konservasi dan pemuliaan tumbuhan diperlukan untuk mengatasi hal tersebut. Dalam upaya konservasi dan pemuliaan tumbuhan diperlukan informasi mengenai fenologi D. maritima Blume. Penelitian bertujuan menganalisis fenologi pembentukan bunga dan buah D. maritima Blume meliputi aspek-aspek yaitu fase dan waktu periode pembungaan, faktor lingkungan yang memengaruhi pembungaan, serta perubahan morfologi perkembangan bunga dan buah. Pengamatan dilakukan pada tiga pohon betina dan tiga pohon jantan D. maritima Blume yang merupakan koleksi Kebun Raya Bogor yang berasal dari Halmahera, Maluku Utara. Satu periode perkembangan bunga dan buah yang meliputi fase inisiasi, fase kuncup kecil, fase kuncup besar, fase antesis (bunga mekar), fase perkembangan buah, dan fase pemasakan buah berlangsung selama ±9–10 bulan (277–292 hari). Iklim mikro kelembapan udara memengaruhi waktu dan ukuran pada fase perkembangan bunga dan intensitas cahaya memengaruhi waktu dan ukuran fase pemasakan buah. Perubahan morfologi ditemukan pada setiap fase meliputi perubahan tekstur, warna dan bentuk.
Keyword: abiotic, Diospyros maritima Blume, morphology, phenology

Judul: Morphological characterization of Hoya diversifolia Blume growing spontaneously in Bogor Botanical Garden
Abstrak: Hoya diversifolia merupakan tumbuhan epifit yang tumbuh subur pada berbagai inang dengan karakter batang berkulit tebal, kasar, dan retak– retak. Penelitian ini bertujuan untuk mengkarakterisasi tumbuhan H. diversifolia dan menyeleksi tumbuhan H. diversifolia terbaik yang tumbuh spontan di Kebun Raya Bogor untuk dikembangkan sebagai tanaman hias. Karakterisasi dilakukan terhadap karakter kualitatif dan kuantitatif organ vegetatif dan generatif dari 30 individu H. diversifolia. Selanjutnya data ditabulasikan dalam bentuk matrik dan digunakan untuk membangun dendogram dengan index RT (Rogers and Tanimoto) dan metode UPGMA. Hoya diversifolia bervariasi pada warna dan ukuran bunga, daun, dan batang. Berdasarkan karakter kualitatif dan kuantitatif, ditemukan individu H. diversifolia yang berpotensi dikembangkan sebagai tanaman hias. Individu ini memiliki sembilan pedunkel dengan rata- rata 18 pedicel disetiap pedunkel., Hoya diversifolia is an epiphytic plant that thrives on various of host stem with thick-skinned, rough, and cracked character. This study aimed to characterize H. diversifolia plants and selecting the best plants that grow spontaneously in the Bogor Botanical Garden to be developed as an ornamental plant. Morphological characterization of qualitatif and quantitative characters was observed from vegetative and generative organs of 30 individuals of H. diversifolia. Furthermore, the data were tabulated and used to construct a dendogram using index RT (Rogers and Tanimoto) and UPGMA method. H. diversifolia varied in color and size of flowers, leaves, and stems. Based on qualitative and quantitative characters, there was an individual of H. diversifolia potentially to be developed as an ornamental plant. This variant had nice peduncle with 19 pedicel each peduncle. Keywords: Hoya diversifolia Blume, Morphology, Bogor Botanical Garden
Keyword: Hoya diversifolia Blume, morfologi, Kebun Raya Bogor

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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