Judul: Variasi DNA Kloroplas Shorea leprosula Miq. di Indonesia Menggunakan Penanda PCR-RFLP
Abstrak: Shorea leprosula is a member of Dipterocarpaceae that occurs predominately in tropical rain forests of Southeast Asia. Dipterocarps consists of many economical and ecologically important species. In this paper PCR-RFLP markers were used to observe cpDNA variation of Shorea leprosula in Indonesia. Leaf samples from individual plants were collected from 13 populations in Java, Sumatra and Kalimantan islands. cpDNA polymorphism was assessed using combination of 4 primers and 10 enzyme restrictions. The result showed that only rbcL-Alu I combination gave polymorphic bands. From these polymorphic bands, two haplotypes were identified, namely haplotype 1 as dominant haplotype in all populations and haplotype 2 , which was found only at Bukit Tigapuluh National Park and Concession Asialog in Sumatra, and Concession ITCIKU in Kalimantan.
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Judul: Variasi DNA Kloroplas Shorea spp (Shorea acuminata Dyer, Shorea leprosula Miq dan Shorea parvifolia Dyer) Berdasarkan Penanda Mikrosatelit.
Abstrak: Shorea acuminata, Shorea leprosula, and Shorea parvifolia are members of the Diptecarpaceae family. They are ecologically and commercially important in the Southeast Asia region. In this present study, we used chloroplast microsatellites (cpSSR) to study the variation within and among Shorea species populations and the distribution of chloroplast DNA haplotypes of Shorea species. Based on chloroplast microsatellite analysis, the following diagnostic haplotypes were detected; namely haplotype A, C, and D for S. leprosula, S. parvifolia, and S. acuminata, respectively. In general, haplotype variation of cpSSR was low in this studies. The highest within population variation of cpSSR was observed in S. acuminata. The highest genetic differentiation was detected in S. parvifolia (Gst = 0.58) followed by S. acuminata (Gst = 0.31) and S. leprosula (Gst = 0.14). The haplotypes distribute evenly among different populations and between islands, and do not correspond with geographical separation among populations and islands. Some haplotypes from one species were shared by other species, indicating the possibility of gene flow via interspecific hybridization, that occurred currently and/or in the past. Introgressive hybridization probably occurred among Shorea species due to co-existance in the forest stands and overlapping flowering times.
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Judul: Desain Mekanisme Pengatur Bibit Nanas untuk Mesin Tanam Nanas.
Abstrak: Penanaman bibit nanas pada saat ini masih dilakukan secara manual dengan kapasitas rendah dan hasil penanaman yang kurang baik. Untuk memperbaiki hal itu, diperlukan mesin tanam nanas berkapasitas tinggi dengan hasil penanaman yang baik. Dalam mesin tanam nanas di mana bibit tertumpuk dengan posisi yang tidak beraturan, diperlukan mekanisme untuk mengatur posisi orientasi bibit nanas dan juga mengumpankan bibit nanas dalam posisi berdiri untuk ditanam. Tujuan dari penelitian ini adalah untuk merancang mekanisme pengatur bibit nanas tipe sucker untuk mesin tanam nanas. Mekanisme yang dirancang ini terdiri dari: 1) mekanisme pembawa bibit dari hoper bibit sekaligus memposisikannya secara tertidur satu persatu, dan 2) mekanisme pengumpan bibit dalam posisi berdiri. Mekanisme ini dirancang untuk dapat mengumpankan bibit dengan kecepatan 5.54 detik per bibit, dan unit conveyor pengarah bibit dirancang dengan kecepatan 0.081 m/s. Hasil pengujian prototipe mekanisme pengarah bibit ini menunjukkan bahwa conveyor pengarah bibit mampu membawa bibit, dan mengaturnya dalam posisi tertidur sebanyak 89.67 %. Unit penegak bibit dapat mengumpankan bibit dalam posisi berdiri sebanyak 92%. Mekanisme pengarah ini mampu mengumpankan bibit dengan kecepatan rata-rata 10.8 bibit per menit.
Keyword: Bibit nanas, conveyor, desain, mekanisme pengatur, mesin tanam