Judul: Optimasi Konsentrasi BAP dan Media Dasar untuk Perbanyakan Sereh Wangi (Cymbopogon nardus) secara In Vitro
Abstrak: Citronella (Cymbopogon nardus) is a herbaceous plant belonging to the Poaceace family which has a lot of uses. It is used as raw material in production of essential oil. Currently citronella production in Indonesia decreases, and it also has lower quality, whereas the seedling price increase. One of the efforts to reduce the seedling price is to apply seedling production by using in vitro propagation technique with a simple basic medium. This study aimed to determine the optimum concentration of BAP and simple basic medium that can be used for citronella in vitro propagation. Application of BAP in MS medium showed significant effect on citronella shoot multiplication. For citronella shoot multiplication, optimum concentration of BAP was 2 mg/l. Basic medium composed of 2 g/l Hyponex (20:20:20) gave the same effect with MS medium for shoot multiplication of citronella, therefore Hyponex medium at a concentration of 2 g/l can be used to substitute the MS medium
Keyword: Bogor Agricultural University (IPB), citronella., plant propagation, Hyponex, Growmore, BAP

Judul: Application Types and Concentrations of Media and Concentrations of BAP on Secondary Protocorm and Planlet Induction of Dendrobium tobaense var. giganteum
Abstrak: Anggrek genus Dendrobium merupakan jenis anggrek yang memiliki nilai ekonomi tinggi dan banyak diminati. Hal tersebut menyebabkan beberapa spesies mulai terancam keberadannya, salah satunya yaitu Dendrobium tobaense var. giganteum. Penelitian ini bertujuan mempelajari pengaruh jenis dan konsentrasi media serta BAP dalam menginduksi proliferasi protocorm sekunder dan planlet D. tobaense var. giganteum secara in vitro. Jenis media yang digunakan yaitu Knudson C, Schenk and Hildebrant, dan Vacin and Went dengan konsentrasi 1/2 dan 3/4 kali konsentrasi hara makro dan mikro. Zat pengatur tumbuh BAP (Benzyl Amino Purine) yang ditambahkan yaitu 0, 1, 2, dan 3 mg L-1. Eksplan yang digunakan adalah protocorm primer D. tobaense var. giganteum aksesi dari hutan Aceh Tengah. Hasil penelitian ini menunjukkan jenis media berpengaruh sangat nyata terhadap pembentukan protocorm sekunder dan tunas D. tobaense var. giganteum. Media yang optimal untuk proliferasi protocorm membentuk protocorm sekunder dan menghasilkan jumlah protocorm sekunder tertinggi yaitu media 1/2 SH sebanyak 1,68 protocorm sekunder. Interaksi jenis media dengan konsentrasi BAP berpengaruh nyata terhadap jumlah kalus. Sebanyak 1,13 kalus berhasil terbentuk pada media 1/2 VW + 2 mg L-1 . Pada pembentukan tunas diperoleh kombinasi media yang optimal yaitu media 1/2 SH + 2 mg L-1 BAP dengan rata- rata jumlah tunas 4,08 tunas per eksplan., Orchid genus Dendrobium is a type of orchid that has high economic value and is in great demand. This has caused several species to be threatened, one of which is Dendrobium tobaense var. giganteum. This study aimed to study the effect of the type and concentration of media and BAP in inducing proliferation of secondary protocorms and plantlets of D. tobaense var. giganteum in vitro. The types of media used were Knudson C, Schenk and Hildebrant, and Vacin and Went with concentrations of 1/2 and 3/4 times the concentration of macro and micronutrients. The growth regulators BAP (Benzyl Amino Purine) added were 0, 1, 2, and 3 mg L-1. The explants used were primary protocorm D. tobaense var. giganteum accession from the forests of Aceh Tengah. Result of this experiment is the type of media had a very significant effect on the formation of the secondary protocorm and shoots of D. tobaense var. giganteum. The optimal medium for protocorm proliferation formed a secondary protocorm and produced the highest number of secondary protocorms, namely 1/2 SH media as much as 1.68 secondary protocorms. The interaction of the type of media with the concentration of BAP significantly affected the number of callus. A total of 1.13 callus were successfully formed on 1/2 VW + 2 mg L-1 media. In the formation of shoots, the optimal combination of media was obtained, namely media 1/2 SH + 2 mg L-1 BAP with an average number of shoots of 4.08 shoots per explant.
Keyword: protocorm, Dendrobium tobaense var. giganteum, Benzyl Amino Purine, Knudson C, Schenk and Hildebrant, Vacin and Went

Judul: igenvalues and Eigenvectors of Tridiagonal Matrix with Non Constant and Recurrent Diagonal Entries.
Abstrak: Matriks tridiagonal adalah suatu matriks yang mempunyai entri-entri bernilai nol kecuali pada diagonal utama, di bawah diagonal utama (subdiagonal) dan di atas diagonal utama (superdiagonal). Entri pada diagonal utama tidak konstan dan berulang. Setiap entri pada matriks tridiagonal ini adalah bilangan kompleks. Dalam karya ilmiah ini, akan dibuktikan 3 teorema untuk menentukan nilai eigen dengan 2 kasus dan 1 teorema untuk menentukan vektor eigen. Teorema pertama menentukan polinomial karakteristik dari matriks tridiagonal. Polinomial karakteristik dari matriks tridiagonal tersebut digunakan untuk menentukan nilai eigen pada teorema kedua dan ketiga serta menentukan vektor eigen pada teorema keempat
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