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: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf