Judul: Pengaruh Perlakuan Asam Askorbat dalam Meningkatkan Toleransi Kekeringan pada Dua Varietas Padi Gogo (Oryza sativa L.)
Abstrak: The aimed of this research was to examine the effects of ascorbic acid treatment to improve drought tolerance of two varieties of upland rice growth under drought stress. The laboratory works consisted of two experiments and were designed to determine the critical osmotic potential of upland rice and to determine the optimum ascorbic acid concentration. The greenhouse study was designed to examine the effects of soaking seed in ascorbic acid on seedling growth under drought stress. Drought condition was simulated by PEG-6000 and regulation of water treatment. During the first experiment,osmotic potential was significant at all variables but varieties and interactions of both osmotic potential and varieties were no significant at all variables. Germination percentage and speed of germination were significantly decreased by increasing of osmotic potential. The second experiment showed that interactions of both factors were no significant at all variables. The result showed that the ascorbic acid treatment only improved the germination percentage and speed of germination compare the control. However, the best result was showed by 55 mM ascorbic acid. The result of green house experiment showed that the interactions were no significant except on leave wide and water deficit 1 WAP. Ascorbic acid treatment was no effect at all variables.
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Judul: Morphology and physiology adaptation of some soybean genotypes [Glycine max (L.) Merr] to drought and aluminium stress
Abstrak: The experiment was carried out to study the effect of drought and aluminium (Al) stress on morphological, physiological and yield component of tolerant and sensitive soybean genotypes. This experiment was conduct on two phase. At first was on June to September 2010 and use a randomized block design (RBD), which consists of three factors: 1) soybean genotypes (Anjasmoro, SC 56-3, PG 57-1, SP 30-4 and Tanggamus), 2) soil water content (100% , 75% and 50% field capacity), 3) the level of Al neutralization (100% neutralization, 75% neutralization and 50% neutralization). Genetically there were differences on plant height, number of leaves, leaves dry weight and root dry weight. Drought decreased plant height, number of leaves, leaves, root and nodules dry weight in most all genotypes. Stems dry weight and number of branches were affected by interact between genotype and water level. Drought and Al stress decreased stems dry weight mostly on all genotypes. On physiological parameter, leaves color index (LCI) and chlorophyll b content, were affected by genotypes. Otherwise, drought increased LCI, chlorophyll a and b content. Al stress decreased chlorophyll b content. The yield component of all genotypes were variety depend on each water level and Al neutralization. Water use efficiency (WUE) on water level 100% field capacity and neutralization Al 100% were optimal condition on most genotype. There were 10 parameters have positive correlated with yield, there are: plant height, number of leaves, number of branch, leaves dry weight, stems dry weight, roots dry weight, pods dry weight, number of pods, number of full pods and pods weight. The result of sensitivity index analysis on 10 variables were classified PG 57-1 as tolerant and SP 30-4 as sensitive genotype to drought and Al stress. The second phase axperiment was conduct on November 2010 to February 2011, use a randomized block design (RBD), which consists of three factors: 1) two soybean genotypes (PG 57-1 and SP 30-4), 2) two level of soil water content (75% and 50% field capacity), 3) the level of Al neutralization (100% neutralization, 75% neutralization and 50% neutralization). There were no differences between tolerant and sensitive genotype on proline content, net assimilation rate (NAR) and relative growth rate (RGR). But on tolerant genotype, nodules dry weight were higher than the sensitive one.
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular