Judul: Yield Potential Evaluation of Tomato Mutant Genotypes for Assembling Tomatoes Tolerant to Cracking Fruit in the Lowlands
Abstrak: Pecah buah merupakan salah satu gangguan fisiologis yang terjadi pada tanaman tomat. Pecah buah dapat mengurangi hasil produksi dan berdampak nyata pada kerugian buah yang dapat dipasarkan. Penelitian ini bertujuan untuk menguji genotipe-genotipe mutan yang toleran pecah buah dan berproduksi tinggi. Penelitian ini dilaksanakan pada bulan Juli-November 2019 di Kebun Percobaan Leuwikopo IPB, Dramaga, Bogor, Jawa Barat. Percobaan dilakukan menggunakan Rancangan Acak Kelompok Lengkap (RAKL) dengan satu faktor yaitu perlakuan genotipe tomat mutan dengan 13 taraf. Penelitian dilakukan dengan tiga ulangan sehingga diperoleh 39 satuan percobaan. Hasil penelitian menunjukan bahwa perlakuan genotipe memberikan pengaruh nyata pada beberapa karakter seperti tinggi tanaman, diameter buah, panjang buah, bobot per buah, bobot buah per tanaman, dan produktivitas. Genotipe M5/990 Kudamati 1/9-4 memiliki nilai bobot per buah dan produktivitas per hektar tertinggi sebesar 934,7 g dan 29,91 ton ha-1 dan toleran terhadap pecah buah dengan kriteria tahan, Cracking fruit is one of the physiological disorders that occur in tomato plants. Cracking fruit can reduce production yields and have a significant impact on marketable fruit losses. This study aims to examine mutant genotypes that are tolerant of fruit breaking and high yielding. This research was conducted in July- November 2019 at the Leuwikopo Experimental Garden, IPB, Dramaga, Bogor, West Java. The experiment was conducted using a Completely Randomized Block Design (RAKL) with one factor, namely the treatment of mutant tomato genotypes with 13 levels. The study was conducted with three replications so that 39 experimental units were obtained. The results showed that the genotype treatment had a significant effect on several characters such as plant height, fruit diameter, fruit length, weight per fruit, fruit weight per plant, and productivity. Genotype M5/990 Kudamati 1/9-4 had the highest weight value per fruit and productivity per hectare of 934.7 g and 29.91 tons ha-1 and was tolerant of fruit breaking with the criteria of resistance.
Keyword: fruit  breaking, tomatoes, plant breeding, productivity

Judul: Genetic Analysis of Quantitative and Fruit Cracking Characters in Tomato (Lycopersicon esculentum Mill.).
Abstrak: Tomato fruit cracking had became one of the problems in lowland cultivation. Morphology characterization of twenty five tomato genotypes were carried out to evaluate the fruit cracking tolerance level and the genetic diversity. Ten genotypes were selected to estimate variance and heritabilities of crack index character, yield and component of yield, fruit and vegetative character and then six genotypes were selected to conduct a 6×6 full diallel cross set of tomato to estimate genetic parameter, combining ability and hybrid performance. The experiment was conducted from April until August 2012 and from April until August 2013 at Leuwikopo Field Station (6o56‟34‟‟S, 106o72‟56‟‟E), Bogor Agricultural University. Randomized complete block design was used with three replications. The genetic diversity was analyzed by clustering analysis. Marker character were selected based on heritabilities value and correlation between character. Genetic parameter was analized by Hayman method and combining ability was analyzed by Griffing Method. The difference between the hybrids and varieties comercial was analyzed by Dunnet‟s tested. Result of resistance evaluation showed that fruit crack index of 25 tomato genotypes range from 0.00 to 20.58. According to quantitative character some genotype can be selected as material breeding. Based on genetic diversity analysis, all genotypes could be divided into four groups. Tomato genotypes IPBT1, IPBT3, IPBT13, IPT33, IPBT60, IPBT64, IPBT73, IPBT 78, IPBT83 dan IPBT86 were recommended as parent of diallel cross to fruit cracking genetic analysis. The marker selection on tomato breeding program to develop tomato varieties that have high yield and fruit cracking resistant using characters with high heritabilities value, correlated significantly and directly influent to the fruit crack index. Fruit cracking character, yield and components of yield, fruit character and vegetative character include to the high category of heritability. According correlation and path analysis the three components very highly correlated with crack index were fruit crack weight percentage of plant, number of fruit crack percentage of plant and total soluble solids. The three components that very highly correlated with yield per plant were marketable fruit weight, individual fruit weight and plant height. Fruit cracking character is controlled by additive and dominant gene effect, but dominant effect more significant than additive effect. Based on genetic parameter and combining ability, the control of additive as well as v non-additive gene effects for all of the character were highly significant. The highest significant reciprocal effect occurs for yield per plant, number of fruit, individual fruit weight, fruit length, fruit diameter, number of locule and fruit thickness. The analysis of variance for general combining ability (GCA) and specific combining ability (SCA) were significant for all traits. Pure line varieties breeding programs could be developed if variance for GCA were highly significant and the genotype parent has a good estimated GCA value. Tomato genotype IPBT78 proved to be the best general combiner for yield and yield components. Hybrid varieties breeding programs developed if variance for SCA were highly significant and the genotype parent has a good estimated SCA value. The most recommended cross combinations are IPBT3×IPBT78, IPBT78×IPBT3, IPBT13×IPBT78 and IPBT64×IPBT78. Hybrids performance show that some character are better than commercial variety
Keyword: correlation, diallel, genetic diversity, Griffing method, Hayman method

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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