Judul: Effectiveness of Arbuscular mycorrhiza fungi and natural phosphorus fertilizer utilization on growth, biomass and asiaticoside production of asiatic pennywort (Centella asiatica l. Urban) on Andosol.
Abstrak: Consumer demands for safe and healthy food require more advanced agricultural production that is free of chemical contaminant and heavy metals harmful for health. Arbuscular mycorrhiza fungi (AMF) as biological agent in several species of plants are now starting to get much attention. AMF are very important which is involved in various biogeochemical of nutrients in order to ensure plant fitness as well as terrestrial ecosystem stability. Currently, it is important to find the alternative materials that can be used as sources of phosphorus due to the need of lower cost, environmentaly friendly, and easily available. Rock phosphate and cow bone meal are some of the natural materials that can be used as a phosphorus sources alternative. Public interest increased to medicines derived from natural products including asiatic pennywort (Centella asiatica L. Urban), and required the availability of adequate of raw material supplies and quality. Cultivation of raw material to produce standardized of asiatic pennywort is not known completely, so its need research support. This dissertation is based on four experiments with the main objective was to find the role of AMF and its relation to the use of natural phosphorus fertilizer on growth, development, biomass, and asiaticoside production of asiatic pennywort. Results of the researches showed that many different types of AMF spores extracted from rhizosphere of asiatic pennywort. Symbiosis AMF with asiatic pennywort was quite compatible that is indicated by high to very high root colonization relatively, and the effectiveness to increase yield and nutrient uptake of N, P, K. Isolates mixture of AMF was more effective than single spores in increasing biomass of asiatic pennywort. Rock phosphate and cow bone meal are the source of natural P that are potential to substitute for synthetic fertilizers, especially on acid soils. Inoculation of AMF increased leaf dry weight, shoot dry weight, and total dry weight by 14.7, 17.1, and 18.0% respectively. Inoculation of AMF significantly increased the growth, nutrient uptake, biomass, and asiaticoside content of asiatic pennywort. Different inoculation timing of AMF did not significantly affect all the variables of growth, development, and plant biomass, but increased asiaticoside production. Timing of inoculation at seedling stage and transplanting resulted on the highest leaf dry weight, shoot dry weight, and total dry weight 4.88 g, 15.22, and 18.05 g plant-1 or increased 77.6, 70.1, and 88.2% respectively, than without AMF (control) plants. Rock phosphate and cown bone meal did not significantly affect growth, development, and plant biomass but provide positive effect on the high roots colonization of AMF 79.4 and 82.0% respectively, than control.
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Judul: Variability and growth response and asiaticoside production of asiatic pennywort (Centella asiatica (L.) Urban) at different site elevations and shades.
Abstrak: In developing products derived from asiatic pennywort there is a lack of guarantee in terms of raw material supply and quality. To support such needs, standardized plant material will ensure production level and quality. The objectives of this research were: 1) to obtain information of the genetic parameters, i.e. of asiatic pennywort morphological characters and criterion of selection to produce high content of asiaticoside and dry shoot production, obtaining asiatic pennywort accessions which have high content of asiaticoside and dry shoot production, and information about the result of asiatic pennywort selection based on independent culling level, a single selection, weighted and unweighted standardized selection indexes, 2) to analyse and evaluate genetic distances of 17 accessions asiatic pennywort based on morphological, RAPD, and the data of markers combination, and 3) to obtain response of the growth and asiaticoside production of six asiatic pennywort plant accessions in different shades on low and high elevation areas. Results of the research showed that number of leaf; length, width, and leaf area: number of vein leaf, and segment length on the longest stolon have wide genetic variability and high heritability. The length and diameter of leaf petiole: leaf thickness, number of runner, content and production of asiaticoside that showed narrow genetic variability and heritability from low to moderate. Narrow genetic variability and high heritability were shown by characters of dry shoot weight. Direct selection toward dry shoot production could be conducted through selection of leaf area. The selection indicated that 4 accessions of asiatic pennywort showed high content of asiaticoside and dry shoot weight, namely Casi 016, Casi 003, Casi 008, and Casi 002. Grouping of asiatic pennywort accessions based on morphological, RAPD, and the basis of markers combination divided the 17 accessions of asiatic pennywort into 4, 5, and 4 groups at similarity level of 0.33, 0.73, and 0.72, respectively. In high elevation, highest production of asiaticoside (2.34 g m-2) and content of asiaticoside above MMI standard (1.33%) occured in Casi 002 planted without shade.
Keyword: Medicinal plants, Genetic variability, High elevation, Shade, Low elevation, Centella asiatica L. (Urban)

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix