Judul: Karakter Vegetatif Dan Reproduktif Tanaman Mutan Padi Toleran Aluminium
Abstrak: Increasing rice productivity is important to stabilize food supply in Indonesia. The rice demand increased annually, but the rice fields decreased rapidly due to transformation of the rice fields into settlement and industry, leaving dry land that are dominated with acid soil for agriculure. Dry soils in wet climate is usually acid, and contains high solubility of toxic compounds such as aluminum (Al) and mangan. Al toxicity is one of problems of rice production in acid soils. Although Al tolerant rice mutant was being developed but its vegetative and reproductive characters have not been characterized. This research was aimed to study vegetative and reproductive characters of Al tolerant rice mutant developed from cultivar IR64 that was originally Al sensitive. Screening of 69 mutant numbers (2323 seeds) based on root regrowth as a screening parameter resulted four rice mutants M2 that were potentially Al tolerant with good primary and secondary roots growth after being exposed to 15 ppm for 72 hours. Vegetative characters of rice that were affected by Al stress were the number of panicle and plant height. Reproductive characters of rice that were affected by Al stress were the number of productive tiller, the date of flowering, and harvesting. The research result showed that the number of productive tiller showed negative correlations with panicle length. The screening of the M3 mutants obtained one number of potentially Al tolerant mutant, 1-12-4-183.
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Judul: Karakter Pertumbuhan Akar sebagai Parameter Toleransi Tanaman Padi terhadap Cekaman Aluminium
Abstrak: The improvement of rice productivity in acid soils could be achieved by utilizing Aluminum (Al)-tolerant rice varieties. The objective of this study was to obtain root growth characters of rice seedling that can be used as an Al-tolerance parameter in rice. The study evaluated three root growth characters, which were Root Re-growth (RRG), Root Elongation (PPA), and Relative Root Length (PAR), in three Al-sensitive (Ciherang, IR64, and Situbagendit) and an Al-tolerant rice varieties (Hawara Bunar). Those four varieties were grown in minimal nutrient solution with and without the addition of 15 ppm Al. The RRG test showed inconsistency between the relative RRG and the nature of Al-tolerance character of the tested rice suggesting the RRG character was not appropriate rice tolerance paramater. Analyses of PPA and PAR showed a consistency between PPA and PAR pattern indicating that both charaters could be used as Altolerance parameter in rice. Haematoxyline root staining showed the presence of Al in cortex and epidermis root tip cell higher in Al-sensitive rice than that of Al-tolerant rice.
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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