Judul: Pengaruh Perlakuan Insersi Bakteri Rhizobium sp. dan Periode Simpan Terhadap Hasil dan Mutu Fisiologi Benih Kedelai (Glycine max L. Merrill)
Abstrak: The purpose of the experiment 1 were to confirm the present of the bacteria Rhizobium sp., which had inserted into the seed tissue through the vacum technology and to study the effect of inserted seed quality during storage periods. Experiment 2 was conducted to study the growth of inserted soybean seed on their ability of producing the soybean seed and to study the performance of the physiological character during the period of storage. The result experiment 1, the microscopy analysis of soybean seed slide indicated that the bacteria Rhizobium sp. were located on the palisade seed tissue. The bacteria remained viable inside the seed tissue during 0 – 4 months storage period. The population of bacteria cell inside the seed tissue were maintained in 10 5 cell per ml. This population was reasonable enough to qualify the requirement of root infection. The quality of seed in term of germination percentage, vigor index and germination speed of seed remained stable until 3 months storage period although the last two variables reduced significantly after 4 months. The vigor index and germination speed were reduced from 90.67 to 58.67 % and from 31.78 to 28.69 % / etmal, respectively. The experiment 2 was conducted using the split plot design with two factors that storage period as the main plot and insertion of bacteria as a sub plot. The result of the experiment showed that during the vegetatif phase, the inserted seed performed best growth which are indicated by better plant of height, number of leaf, number of nodules, wet and dried weight of nodules. Similarly during the generatif phase, the ability of plant on producing the soybean seed which are indicated from the wet and dried weight of upper and lower plant biomass, number of pod, dried weight of pod including dried weight of seed, inserted seed significantly better than control plant. The quality of seed which produced from inserted seed plant, in term of germination speed and vigor index of seed was also better than seed produced from control plant. In conclusion, inserted seed with Rhizobium sp. could support the growth of soybean plant and producing the good quality of soybean seeds compared from the uninserted soybean seed.
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Judul: Pengaruh perlakuan rizobakteri pada benih dan tanaman serta pemupukan fosfat terhadap pertumbuhan tanaman tetua betina jagung hibrida
Abstrak: The use of quality seeds from improved varieties will produce plants more productive and efficient. Seed quality constitute of genetic, physical, physiological, and health quality. Phosphate fertilizer can enhance plant growth, however only 10-30% of fertilizer P that can be absorbed by plants. The use of rhizobacteria can enhance phosphate uptake and plant growth. The objectives of this study were to improve the quality of physiological seeds and plant growth hybrid corn using rhizobacteria and phosphate fertilizers. The research has conducted in three stages of experiments in the laboratory, greenhouse and in the field. Experiment used parent of hybrid corn seed cv. Bima-3, namely: Nei9008 (female parent) and Mr14 (male parent). The groups of isolates Actinomycetes, Bacillus spp. and fluorescent pseudomonads are used in these experiments. The experiment steps were: (1) characterization and screening of rhizobakteria, (2) Evaluation of selected rhizobacteria on seed quality and seedling growth of female parent and (3) Effect of rhizobakteria treatment and phosphate fertilizer on plant growth of female parent. Experiment 3 were conducted in two seasons, season I using six isolates selected from Experiment 1 and 2, while the season II using two isolates which indicated the best result from season I. In the field experiment, the seeds has planted in polybags with sterilized soil. Experiment 3 was arranged in Split Plot Design. The main plot consisted of five doses of phosphate fertilizer, which is 0, 75, 125, 175, and 200 kg SP-36/ha (100% of recommended dosage). Subplot is rhizobacteria treatment. The results showed, there were five isolate choosed from 10 isolates of each genus of rhizobacteria based on the criteria of high producing phosphatase, negative hypersensitive reaction test, producing IAA and chitinase. Experiment 2 showed the rhizobacteria B28 and B46 increase growth rate and seed vigor index. The results of Experiment 1 and 2, rhizobacteria AB2, ATS4, B28, P14 and P31 was selected based on the ability to improve the physiological seed quality of female farent and rhizobacteria B42 based on the highest production of IAA (14.4 μg/ml). Field experiment at the season I, there were rhizobacteria ATS4 and B28 increased plant growht compare to other rhizobacteria. The results from season II, ATS4 has potential to promote plant growth with average number of leaf and plant height at 4 weeks after planting 5.2 and 56.88 cm compared to control 4.8 and 55.98 cm respectively. Phosphate fertilizer strongly influenced on the average number of leaves and plant height. In the season II at 2 and 4 weeks after planting, fertilizing with the recommended dose (200 kg SP-36/ha) showed highest average the number of leaves and the plant height compared with other treatments.
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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