Judul: Penetapan Kadar Air Kapasitas Lapang dengan Metode Alhricks, Drainase Bebas, dan Pressure Plate pada Berbagai Tekstur Tanah untuk Tanaman Bunga Matahari (Helianthus annuus L.)
Abstrak: Soil water availability is one of the important factors influencing plant growth. Field capacity is an upper limit of available water for plants. Field capacity can be determinated by different methods. The objectives of this research are to compare among methods of field capacity measurement and to observe a response of sunflower growth in the range of field capacity that define with different methods. This research was initiated with field capacity measurement with three diffrent methods, i.e. Alhricks, Free drainage, and Pressure Plate at different soil textures, i.e. clay, sandy clay loam, and sandy loam. Furthermore, sunflower planting with different watering treatment based on field capacity of each mentioned methods was carried out in greenhouse. The research was designed by completely randomized design factorial with three replications. The result showed that soil texture and field capacity method and interaction of both significantly affected a field capacity value. In clay textured soil, watering treatment based on field capacity of each method did not significantly affect on plant height, number of leaves, stem diameter, and dry root biomass but significantly affected on wet root biomass, wet and dry canopy biomass, and root length. The result also showed that different texture will affect growth response of sunflower.
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Judul: Pengaruh penambahan pasir dengan ketersediaan air maksimum pada tanah Paleudult tipik Parung dan pertumbuhan tanaman bunga matahari (Helianthus annuus L.)
Abstrak: Ketersediaan air tanah sangat menentukan untuk keperluan dan perkembangan tanaman. Penelitian ini bertujuan untuk melihat hubungan tekstur tanah dengan ketersediaan air maksimum bagi tanaman dan melihat respon pertumbuhan bunga matahari pada kisaran kapasitas lapang. Disamping itu penelitian ini juga ingin melihat pada pF berapa sebenarnya kapasitas lapang dicapai. Penelitian ini menggunakan tanah Paleudult Tipik dengan perlakuan penambahan pasir sehingga tanah berubah klas teksturnya. Adapun klas tekstur yang dicobakan adalah tekstur liat (T0) dengan kandungan pasir 5%, tekstur liat berpasir (TI) dengan kandungan pasir 50%, tekstur lempung liat berpasir (T2) dengan kandungan pasir 65%, dan tekstur pasir berlempung dengan kandungan pasir 80%. Perlakuan pemberian air dilakukan pada 40%, 60%, 80%, 100%, dan 120%. Rancangan percobaan yang digunakan adalah rancangan faktorial acak lengkap 4 X 5. Untuk membandingkan pengaruh masing-masing perlakuan dilakukan uji Tukey. Pada tahap awal dilakukan pengukuran kadar air kapasitas lapang dengan menggunakan metoda Alhricks, kemudian dilanjutkan dengan penanaman bunga matahari dirumah kaca. Pada pertumbuhan vegetatif maksimum tanaman dilakukan pelayuan ..dst
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Judul: Mitochondrial DNA Gene Organization and Phylogenetic Relationship of Naja siamensis
Abstrak: Naja siamensis is one of Asiatic cobra in the Family of Elapidae, known as a cryptic snake. It has many morphological variations that lead to misidentification. Misidentification can cause the wrong concept in developing antivenom types due to high snakebite cases occur in Thailand. Thus, an accurate species identification using a molecular approach is crucially required. Mitochondrial DNA has been used widely in snake molecular studies. These studies were aimed to determine the arrangement of the N. siamensis partial mitochondrial genes using reptile-oriented primers and to reveal the phylogenetic relationship among other species of Asian cobra. DNA extraction was carried out based on the standard DNA salting-out protocol and was conducted by bioinformatics analysis using BLASTn and MEGA 6 software. Gene annotation was performed against N. kaouthia complete genome. A total of 3121 bp of N. siamensis mtDNA genes were sequenced consisting of partial of six regions: 16S rRNA, ND1, tRNA-Ile, CRII region, tRNA-Leu, tRNA-Gln, and COI genes. The mtDNA gene organization of N. siamensis was predicted to has a similar pattern with the common Elapidae mtDNA gene organization. This study showed that there is a monophyletic form in Naja genus and N. kaouthia is the closest species with N. siamensis based on partial 16S rRNA and ND1 gene.
Keyword: 16S rRNA, Elapidae, ND1, phylogenetic relationship