Judul: Improve Selection Method of Rice for Suboptimum Phosphorus
Abstrak: Ketersediaan fosfor (P) yang rendah di tanah masam dan daya beli petani yang rendah merupakan faktor yang menyebabkan permasalahan kekurangan unsur hara P di berbagai wilayah budidaya padi. Pengembangan varietas yang adaptif terhadap kondisi P suboptimum sangat penting untuk meningkatkan produktivitas padi pada wilayah tersebut. Metode seleksi yang efektif merupakan faktor penting dalam program pemuliaan untuk mengatasi permasalahan kondisi P suboptimum. Penelitian ini bertujuan mengembangkan metode seleksi yang efektif untuk menghasilkan galur padi yang adaptif pada kondisi tanah P suboptimum. Kegiatan penelitian dilaksanakan selama empat musim tanam dari bulan April 2012 hingga bulan Desember 2014 di KP Muara, Bogor dan lahan petani di Desa Leuwiliang. Dua kombinasi persilangan digunakan pada penelitian ini yaitu IR6008023/Bemas Prima dan Gampai/Progol. Dua populasi generasi F 3 ditanam pada lingkungan seleksi P suboptimum di KP Muara Bogor, mulai bulan April sampai Agustus 2012 dengan menggunakan metode seleksi bulk. Benih generasi F 4 dipanen dan dibagi empat untuk diseleksi pada lingkungan P optimum (36 kg ha-1 P2O5) dan P suboptimum (tanpa diberi pupuk P) dengan metode pedigree dan bulk modifikasi hingga generasi F 5• Dari setiap populasi, metode seleksi dan lingkungan seleksi dipilih 40 tanaman untuk dievaluasi pada generasi F6• Evaluasi generasi F6 dilakukan di lahan petani Desa Leuwiliang, Jawa Barat dari bulan Juli sampai Desember 2014. Populasi generasi F6 ditanam pada lingkungan produksi P optimum dan P suboptimum menggunakan rancangan augmented., The low availability of phosphorus (P) in acid soils and low purchasing power of farmers is a factor that led to the problem of P deficiency in different rice cultivation areas. The development of varieties that are adaptive to P sub-optimum condition is important to increase the productivity of rice in the region. Effective selection method is an important factor in breeding programs to overcome the problems of P sub-optimum conditions. This research aimed to develop an effective selection method to produce rice lines that are adaptive to the sub-optimum P conditions. The research was carried out during four seasons from April 2012 to December 2014 in Muara Experimental Farm, Bogor and farmers' land in the Leuwiliang village. Two cross combinations were used in this research i.e IR6008023/Bernas Prima and Gampai/Progol. Two populations of F3 generations were planted in the sub-optimum P selection environment in Muara Experimental Farm, Bogor from April to August 2012 using bulk selection method. The F 4 generation seed were harvested and split into four to be selected at the optimum P environment (36 kg ha-1 P2O5) and sub-optimum P (without P) with pedigree and bulk modified methods until F5 generation.
Keyword: bulc modification, pedigree selection method, rice, selection environment, Rice Cultivation, Acid Soils, Adaptasi Tanaman, Plant Biotechnology, Rice Productivity, production environment, optimum and suboptimum phosphor

Judul: Studi Mikrob Pelarut Fosfat untuk Mengurangi Dosis Pupuk P Anorganik pada Sistem Budidaya Padi Pengelolaan Tanaman Terpadu (PTT) dan System of Rice Intensification (SRI)
Abstrak: Phosphorus (P) fertilizer has an important role in increasing the production of paddy rice (Oryza sativa L.). Application of high rate P fertilizer is not suitable with the availability of P in the soil because most P bounded by Al, Fe and Ca so make it unavailable to plants. This leads to inefficient use of P fertilizers. Utilization of phosphate solubilizing microbes (PSM) is one of the means to increase the availability of P that can be absorbed by plants, thus reducing the use of inorganic-P fertilizer. Therefore, the aims of the experiment were (1) isolating and selecting some phosphate solubilizing microbes, (2 )to test its effectiveness of PSM in increasing the availability P available on cultivation system of ICM and SRI, (3) to know the effect of PSM to reducing rate inorganic-P fertilizer on the growth and yield of rice. The experiment was conducted of two experiment. First experiment was conducted in Soil Biotechnology Laboratory, Department of Soil Science and Land Resources, Faculty of Agriculture, Bogor Agricultural University in October 2011 - April 2012. Second experiment was conducted at Field Experiment Sawah Baru, University Farm, Bogor Agricultural University in May to August 2012. The first experiment was (1) isolating and selecting PSM (phosphate solubilizing bacteria and fungi) from biofertilizers. (2) Phosphate solubilizing index test (PSI) to measure the clear zone around the colony. (3) Test the ability of solubilizing P from insoluble phosphate source (Ca3(PO4)2, AlPO4, FePO4). (4) Antagonistic test to know ability of phosphate solubilizing bacteria and fungi and compatibility both in the growing medium and identified of phosphate solubilizing bacteria and fungi. The second experiment was conducted using a split block design with two factors and three replications. First factor as main factor is cultivations system (ICM and SRI) and second factor as sub plot is Combination of rate inorganic-P fertilizer and PSM namely 100% inorganic-P; 75% inorgaic-P; 75% inorganic-P + Phosphate solubilizing bacteria (PSB); 75% inorganic-P + phosphate solubilizing fungi (PSF); 50% inorgaic-P; 50% inorganic-P + PSB; 50% inorganic-P + PSF; PSB only; PSF only; and PSB + PSF. The results of laboratory experiment obtained isolate of PSB BPFA5 (Pseudomonas aeruginosa) and the isolate of PSF FPFE1 (Aspergillus niger) has high phosphate solubilizing index, with wide of clear zone is 2.29 and 1.22, ability of phosphate solubilizing from P source Ca3(PO4)2 is 259.86 dan 537.26 ppm-P and compatible (non antagonistic) in same medium. Both of these isolates used for inoculation in the field. The result of second experiment in the field showed that treatment of cultivation system produced that number productive of tillers, weight of dry plant ,number of grain per panicle, weight of 1000 grain, yield, and population of phosphate solubilizing microbes higher on SRI cultivation system than ICM cultivation system. Combination of 75% inorganic-P fertilizer + PSM on SRI cultivation system produced number of productive tillers, yield, and uptake P of viii grain higher than other treatments. PSM application (PSB and PSF) increase of yield and nutrient-P uptake of straw and grain.
Keyword: integrated crop management (ICM), phosphate solubilizing bacteria, phosphate solubilizing, fungi, system of rice intensification (SRI)

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology