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Degradation in soil fertility is an enormous problem in agricultural intensification system. Availability in phosphate is one of among encountered problems. Peat soils have large areas and great potential for agriculture and plantations, but have many obstacles in their management. One of the issues is the low soil fertility and low availability of nutrients, especially phosphate which exists in many organic forms that are not available to plants. Phosphorous is an essential element after nitrogen, which plays an important role in plant growth and metabolism and the process of soil microbiology. Introduction of phosphate-solubilizing bacteria (PSB) as biofertilizer, is a renewable energy based which can increase the availability of phosphate to plants can overcome this problem and at the same time reducing the use of inorganic P fertilizer. Indigenous PSB, isolated from palm oil plantation could be used as a better and friendly bio-agent to improve soil fertility, specifically for phosphate availability. Eight PSB have been isolated from peat soil in oil palm platation. Morphological, biochemical characterization and molecular identifications showed that the 8 isolates belonged to Flavobacterium and Enterobacter genera, more precisely the species of Burkholderia sp and Novosphingobium nitrogenifigens. Characterization of isolates of the highest PSB activity consisted of the ability to dissolve phosphate in Pikovskaya solid medium, temperature resistance optimization and the ability to produce phosphatase enzyme. Results showed that isolate with the highest potentiality of dissolving phosphate formed 3.5 cm of clear zone diameter and the phosphatase activity at 9 days of incubation 5.992 units (μmol / ml / min). The peak of enzyme's activity was reached at 6 days , which corresponded to 54.782 ppm of phosphorus solubilised. The lowest pH (3.2) was reached at 1 st day of incubation. These isolates showed the ability to grow optimally at temperature range of 25 to 30 0 C. Indigenous PSB could be used as biofertilizer agents which are eco friendly.

<p>ABSTRACT</p><p>Effort to increase productivity and other elite characters in Indonesia oil palm breeding program is facing a problem because of the narrow genetic diversity. To broaden the genetic diversity, germplasm exploration has been done in Angola, Central Africa. The objective of this research was to assess the genetic diversity and population structure of Angola originated oil palm germplasm based on 20 SSR markers. The plant materials used were 27 accessions consisted of 136 palms planted in Riau, Sumatera. The DNA was isolated and amplified using PCR. Phylogeny analysis was constructed using Unrooted Neighbor-Joining by DARwin software 6.0.8. The result showed that polymorphic information content (PIC) value is 0.55 (0.17 to 0.75 for each locus) with 102 total number of alleles. Genetic diversity between individuals was higher compared to the genetic diversity within accessions or regions and between accessions or regions. Phylogenetic analysis of 27 accessions showed that accessions were divided into three main groups. Every group containing individuals originated from 5 spatial distribution regions. Principal coordinates analysis (PCoA) showed that accessions were distributed in one structure. Using more primers and samples to get more representative data is recommended for the following research.</p><p>Keywords: allele, locus, germplasm, molecular marker, polymorphic</p>

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