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: Optimization of Basic Media and Growth Regulator for In Vitro Multiplication of Jeruk Kunci (Citrus x microcarpa Bunge) Plant
Abstrak: Jeruk kunci (Citrus x microcarpa) merupakan tanaman jeruk dengan habitus semak yang banyak tumbuh di wilayah Bangka-Belitung. Jeruk ini memiliki banyak manfaat baik secara langsung atau tidak langsung. Akan tetapi, pertumbuhan dan perkembangbiakannya lambat, sehingga salah satu upaya memperbanyak tanaman tersebut ialah dengan kultur in vitro. Penelitian ini bertujuan menentukan kombinasi antara media dasar MS atau DKW dengan BAP yang optimal untuk multiplikasi tunas jeruk kunci secara in vitro. Penelitian ini menggunakan RAL dengan dua faktor, yakni jenis media dan taraf konsentrasi BAP. Pemberian BAP pada 0,1-2,0 mg/L ke dalam media MS atau DKW mampu menginduksi kalus dan tunas adventif dibandingkan tanpa BAP. Perlakuan DK3 dan DK4 menunjukkan waktu muncul kalus tercepat pada minggu kedua, sedangkan waktu muncul tunas adventif secara berurutan juga paling cepat pada minggu ketiga dan kelima. Rata-rata jumlah tunas adventif (7,2 tunas), tinggi tunas (2,14 cm), jumlah tunas aksilar (19,6 tunas), dan jumlah daun (50,4 helai) tertinggi ditunjukkan oleh perlakuan DK3., Citrus x microcarpa, given in Indonesia as jeruk kunci, is a citrus plant with a shrub habitus that grows in the majority in the Bangka-Belitung Islands, offering numerous direct and indirect benefits. However, its growth and reproduction are slow, so one of the efforts to reproduce the plants is by in vitro culture. This study aimed to determine an optimal combination of MS or DKW basic media with benzyl amino purine (BAP) growth regulator to get multiple shoots in vitro. This study was designed in CRD with two factors: the basic media type and BAP concentration levels. The provision of BAP at 0,1-2,0 mg/L added to MS or DKW media induced callus and adventitious buds compared to the control without BAP. The DK3 and DK4 treatments showed the fastest callus emerging time, which was in the second week, while adventitious buds were also obtained the most rapid in both media, the third and fifth weeks, respectively. The highest average number of adventitious buds (7,2 buds), shoot height (2,14 cm), number of axillary buds (19,6 buds), and number of leaves (50,4 leaves) were shown by treatment DK3.
Keyword: adventitious bud, axillary bud, BAP concentration, basic medium

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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