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 Vegetatif Dan Reproduktif Tanaman Mutan Padi Sensitif Aluminium
Abstrak: Aluminum (Al) tolerant mechanism in rice has not been fully understood. Aluminum tolerant mechanism can be studied using Al-sensitive plant originated from Al-tolerant plant. The research objective was to study the vegetative and reproductive characters of Al-sensitive rice mutant derived from rice cv Hawara Bunar (HB) that originally tolerant to Al. Seedlings of rice mutant generation M2 were screened using hydroponic technique based on Root Re-growth (RRG). Five days old seedlings were grown on minimum culture solution containing 15 ppm of Al for 72 hours and then transferred to non Al-treated culture solution for 48 hours. The value of RRG was determined based on the length difference between root seminal length after recovery and after Al stress. The selected seedlings were grown in green house according to low land rice cultivation technique. The result showed that the seminal root of Al sensitive rice mutants was not able to regrow during period of recovery. The screening result obtained 13 numbers of Al-sensitive mutants in M2 generation. Mutant number 20-11 had the lowest of RRG average value and the highest percentage of mutants. Vegetative and reproductive characters of rice mutant generation M2 were varied significantly. Mutant plants similar to wild type were numbers 20-11-5, 16-20-14, and 20-11-6. The mutant numbers 20-11-5 and 20-11-6 were potential to be developed, because they were the most similar to the wild type, except the tolerance to Al. Al-sensitive mutant plants is not fully stable until the third generation.
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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