Judul: The Growth Performance of Rhizophora apiculata Blume Seedlings Using Cut-Propagule Method
Abstrak: Penurunan luas hutan mangrove Indonesia yang tinggi membutuhkan upaya rehabilitasi yang efektif dan efisien. Salah satu upaya yang dilakukan adalah pemanfaatan Rhizophora apiculata sebagai jenis mangrove yang adaptif dan cepat tumbuh serta metode pembibitan stek propagul untuk mempercepat perbanyakan tanaman. Tujuan dari penelitian ini adalah menganalisis kinerja pertumbuhan propagul R. apiculata dengan berbagai perlakuan stek propagul, media semai, dan pemberian zat pengatur tumbuh (ZPT), serta menentukan kombinasi perlakuan terbaik untuk pertumbuhan R. apiculata. Penelitian eksperimental dilakukan di rumah kaca dengan menggunakan rancangan acak lengkap dengan 3 faktor dan 3 ulangan. Interaksi semua faktor perlakuan (AxBxC) hanya berpengaruh nyata terhadap pertambahan jumlah daun R. apiculata. Propagul lengkap dan propagul stek bagian bawah dengan kombinasi media semai lumpur+pasir dan ZPT 10.000 ppm (a0b1c1 dan a2b1c1) menghasilkan nilai terbaik pada pertumbuhan R.apiculata. Metode semai stek propagul R.apiculata dapat digunakan sebagai alternatif perbanyakan vegetatif massal dalam kegiatan rehabilitasi mangrove., A high decrease in the size of Indonesia's mangrove forests requires effective and efficient rehabilitation efforts. One of the efforts is the use of Rhizophora apiculata as the adaptive and fast-growing mangrove species and its cut-propagule seedling method for accelerating plant propagation. The objectives of this study were to analyze the growth performance of R. apiculata propagules with various treatments of propagule cutting, seedling media, and giving growth regulators (PGR), as well as to determine the best combination of treatment for the growth of R. apiculata. An experimental study was conducted in a greenhouse using a randomized design with 3 factors and 3 replications. Interaction of all treatment factors (AxBxC) only had a significant effect on the increase in the number of leaves of R. apiculata. Complete propagules and the lower part of cutting propagules with a combination of mud+sand seedling media and 10 000 ppm PGR (a0b1c1 and a2b1c1) resulted in the best value on the growth of R.apiculata. Cut-propagule seedling method of R.apiculata can be used as an alternative to mass vegetative reproduction in mangrove rehabilitation activity.
Keyword: Mangrove, cutting propagule, Rhizophora apiculata, vegetative reproduction

Judul: Pengaruh media simpan, ruang simpan, dan lama penyimpanan terhadap viabilitas Propagul Rhizophora stylosa Griff.
Abstrak: Indonesia as an archipelagic country has a coastline and partly overgrown with mangrove forest which is the dominant type of coastal areas. However, at present the mangrove forests have been degraded which causes a decrease in forest potency. The effort that can be done to improve the return potential of these mangrove forests is by rehabilitation of mangrove forest. Rhizophora sp., including the type of Rhizophora stylosa Griff., is a pioneer tree species in the mangrove forest which has an important meaning in the mangrove forest etablishment. The main problem of this type of R. stylosa that is the seed classified into the recalcitrant ones. Therefore, the technique of seed storage is a very important activity to be developed for supporting the success of mangrove rehabilitation activities that have been degraded. The purpose of this study is to discover the influence of storage media, storage room, and time of storage on the propagule viability of R. stylosa, and to compare the R. stylosa propagule germination potential between cutting test and directly propagule germination test results. The research was conducted at the greenhouse and Silviculture Laboratory, Faculty of Forestry IPB and Seed Technology Research Institute Laboratory (BPTP), Bogor. This study used a factorial experiment with completely randomized design (CRD) factorial 5x2x2 with 3 replicates. The details of the factors are: factor A (time of storage) consists of A0 (0 weeks), A1 (1 week), A2 (2 weeks), A3 (3 weeks), and A4 (4 weeks); factor B (storage room) consists of B1 (AC room) and B2 (living room); and factor C (storage media), consists of C1 (sawdust) and C2 (coconut husk). The data collected is propagule viability, the percentage of rooted propagule, moisture content of propagule, propagule germination, germination value of propagule, the growth rates of propagule and shoot and seedling root to ratio of R. stylosa. Based on these results, it is known that the influence of interaction between treatment storage time, storage room, and storage media caused a significant difference to variable germination propagule R. stylosa. The influence of interaction between storage time and storage media caused significant differences on germination, germination value, the growth rates of propagule, and seedling root to shoot ratio of R. stylosa. The influence of interaction between storage room and storage media caused significant differences to the percent of rooted propagule R. stylosa. In this study, coconut husk media storage that is placed in the air conditioner room capable to maintaining the viability of R. stylosa propagule until the time of storage for 4 weeks. The result of estimation R. stylosa propagule viability with cutting test is relatively similar with the directly propagule germination test results.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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