Judul: Characterization of The Reproductive Structure of Fern in Heath Forest of Mount Agung and Tebat Rasau Ibu, Belitung
Abstrak: Hutan kerangas merupakan hutan dengan vegetasi yang tumbuh pada tanah kaya pasir kuarsa, miskin hara, dan memiliki pH rendah. Hutan kerangas mendominasi sebagian ekosistem hutan di Belitung. Jenis vegetasi yang dapat tumbuh di hutan kerangas salah satunya tumbuhan paku. Penelitian ini bertujuan mengkarakterisasi struktur reproduksi tumbuhan paku yang tumbuh di hutan kerangas Gunung Agung dan Tebat Rasau Ibu, Belitung. Struktur reproduksi diamati dari daun fertil tumbuhan paku dengan menggunakan mikroskop stereo dan mikroskop majemuk yang dihubungkan dengan kamera optilab. Data disajikan dalam bentuk gambar, tabel dan kunci identifikasi, kemudian dianalisis secara deskriptif. Tumbuhan paku yang diamati bervariasi pada susunan dan letak sporangia yaitu sporangia dalam strobilus, segmen seperti jari di tepi daun, sorophore, dan sorus. Sorus berbentuk garis, bulat, dan tabung. Sebagian besar sorus terletak pada tepi daun dan di sekitar tulang daun lateral. Spora dari 12 jenis tumbuhan paku memiliki bentuk dasar elips dengan laesura garis, satu jenis bentuk bulat dan tujuh jenis berbentuk tetrahedral-globose dengan laesura triradiate. Ukuran spora yang dijumpai yaitu medium, besar, dan gigantik. Semua spora memiliki nilai rasio P/E <1,00 dengan tipe oblate, suboblate, dan peroblate. Permukaan perispora sangat beragam yaitu echinulate, cristate, plain/laevate, papillate, echinate, alate, reticulate, verrucate, granulate, globules, tuberculate, dan ridges., The heath forest is a forest with vegetation that grows on soils rich in quartz sand, deficient in nutrients, and have a low pH. The heath forest dominates some of the forest ecosystems in Belitung. One of the types of vegetation that can grow in the heath forest is pteridophytes. This study aimed to characterize the reproductive structure of pteridophytes growing in the heath forests of Mount Agung and Tebat Rasau Ibu, Belitung. Reproductive structures were observed from the fertile leaves of pteridophytes using a stereo microscope and a compound microscope connected to an optilab camera. The data obtained are presented in the form of figures, tables, and identification keys, then analyzed descriptively. The pteridophytes observed varied in the arrangement and location of the sporangia, namely sporangia in the strobilus, finger-like segments on the leaf margins, sorophore, and sorus. Sori are lines, round or tubular in shape. Most sori are located on the leaf margins and around the lateral veins. Spore of 12 species have an ellipsoid spore with linear aperture, one species has a spheroidal spore, and seven species have tetrahedral-globose spore with triradiate aperture. The size of the spores found is medium, large, and gigantic sizes. All spores had P/E ratio values <1,00, with oblate, suboblate, and peroblate spore types. The perispore surface is very diverse: echinulate, cristate, plain/laevate, papillate, echinate, alate, reticulate, verrucate, granulate, globules, tuberculate, and ridges.
Keyword: heath forest, perispore surface, pteridophytes, spore morphology

Judul: Diversity of Reproductive Structures in Epiphytic Ferns in the Campus Area of IPB, Dramaga, Bogor
Abstrak: Institut Pertanian Bogor merupakan kampus dengan biodiversitas tinggi. Tumbuhan paku epifit menjadi salah satu tumbuhan yang sangat melimpah jumlah dan jenisnya, tetapi informasi struktur reproduksinya masih terbatas. Penelitian ini bertujuan mengkarakterisasi struktur reproduksi tumbuhan paku epifit yang tumbuh di kawasan kampus IPB, Dramaga, Bogor. Metode penelitian terdiri dari koleksi sorus, pengawetan dengan alkohol 70%, pengamatan menggunakan mikroskop majemuk yang dihubungkan pada kamera optilab, dan pengukuran menggunakan aplikasi imageRaster v2.1. Tumbuhan paku epifit yang diamati bervariasi pada susunan dan letak sorus serta ciri sporanya. Sorus berbentuk bulat dan garis. Sebagian besar sorus terletak pada tepi daun. Sebanyak 22 jenis tumbuhan paku yang memiliki spora bentuk monolete dengan laesura garis, satu jenis bentuk bulat, dan satu jenis bentuk tetrahedral-globose dengan laesura triradiate. Ukuran spora yang dijumpai yaitu medium, besar dan sangat besar. Semua spora memiliki nilai rasio P/E ≤1,00 dengan tipe peroblate, oblate, suboblate, oblate bulat dan prolate bulat. Permukaan perispora sangat beragam yaitu alate-angular, globules, shallow verrucae, verrucate, echinulate, tuberculate, rugate, globules, echinate, laevate, cristate, regulate, colliculate, granulose, dan costate-alate., Bogor Agricultural University is a campus with high biodiversity. Epiphytic ferns are one of the most abundant plants in terms of numbers and types, but information on their reproductive structures is still limited. This study aims to characterize the reproductive structure of epiphytic ferns that grow in the IPB campus area, Dramaga, Bogor. The research method consisted of a collection of sorus, preserving it with 70% alcohol, observing using a compound microscope connected to an optilab camera, and measuring using the imageRaster v2.1 application. The observed epiphytic ferns varied in the arrangement and location of the sorus and the characteristics of the spores. The sorus was round and line. Most of the sorus were located on the leaf margins. A total of 22 fern species had monolete spore with line laesura, one species had round spore, and one species had tetrahedral-globose spore with triradiate laesura. Spore sizes found were medium, large, and very large. All spores had a P/E ratio value of ≤1.00 with peroblate, oblate, suboblate, round oblate, and round prolate types. The surface of the perispora is very diverse, namely alate-angular, globules, shallow verrucae, verrucate, echinulate, tuberculate, rugate, globules, echinate, laevate, cristate, regulate, colliculate, granulose, and costate-alate.
Keyword: biodiversity, characterization of spores, perispore surface, sorus

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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