Judul: Evaluation of Melon Genotypes (Cucumis melo L.) for Breeding New Hybrid Varieties
Abstrak: Indonesia merupakan negara produsen serta konsumen buah melon (Cucumis melo L.), tetapi impor benih melon dari luar negeri masih cukup besar. Hal tersebut membuka peluang pemulia tanaman untuk merakit varietas hibrida unggul. Penelitian ini bertujuan mempelajari karakteristik beberapa genotipe melon dan memilih genotipe potensial untuk materi perakitan varietas hibrida baru. Genotipe yang digunakan ialah enam genotipe dari koleksi Pusat Kajian Hortikultura Tropika (PKHT) IPB (IPB G1, IPB G30, IPB G41, IPB 240, IPB 283, Glamour-S1), tiga galur inbrida PKHT IPB (IPB M13, IPB M23, IPB M21), dan satu varietas pembanding (Alisha F1). Genotipe yang memiliki potensi sebagai materi pemuliaan adalah IPB G1, IPB 240, IPB G41, dan Glamour-S1. Genotipe IPB G1 dan IPB 240 memiliki keunggulan penampakan buah menarik. Genotipe IPB G41 memiliki kandungan padatan terlarut total yang tinggi dan rasanya sangat manis. Genotipe Glamour-S1 memiliki keunggulan penampakan buah menarik serta buah yang besar. Karakter bobot buah berkorelasi positif dengan diameter buah dan panjang buah. Kandungan PTT berkorelasi positif dengan umur panen., Indonesia is a melon producing as well as consuming country, yet unfortunately, the amount and value of seed import is still high. This opens an opportunity for plant breeders to develop improved hybrid varieties. This study aimed to determine the characteristics of several melon genotypes and to select potential genotypes as breeding materials for obtaining improved hybrid varieties. The genotypes used were six genotypes from a collection of the Center for Tropical Horticulture Studies (PKHT), IPB University (IPB G1, IPB G30, IPB G41, IPB 240, IPB 283, Glamour-S1), three inbred lines from PKHT IPB (IPB M13, IPB M23, IPB M21), and one commercial hybrid variety as a check (Alisha F1). Four potential melon genotypes for breeding materials are IPB G1, IPB 240, IPB G41, and Glamour-S1. IPB G1 and IPB 240 had an attractive fruit appearance. IPB G41 had a high total soluble solids content, while Glamour S1 had a large and attractive fruit appearance. Fruit weight was positively correlated with fruit diameter and fruit length. Total soluble solids was positively correlated with days to harvest.
Keyword: Genetic diversity, Melon breeding, Potential genotypes

Judul: Evaluation of Melon Genotypes (Cucumis melo L.) and Their Hybrids for Breeding Improved Varieties
Abstrak: Peningkatan kualitas melon dapat dilakukan dengan mengembangkan varietas hibrida unggul yang dilandasi oleh fenomena heterosis. Penelitian ini bertujuan mengidentifikasi genotipe potensial melon (Cucumis melo L.) dengan kualitas buah yang baik dan mengevaluasi karakter hibridanya. Penelitian dilakukan di rumah kaca Kebun Percobaan Cikabayan, Institut Pertanian Bogor, Bogor pada bulan November 2020–Maret 2021 dan di lahan terbuka Desa Tanjungsari, Kec. Jogorogo, Kab. Ngawi, Jawa Timur pada bulan April–Juli 2021. Bahan genetik pada percobaan I ialah IPB G30, IPB G1, IPB M23, IPB M21, dan varietas Alisha F1. Bahan genetik percobaan II yaitu 13 genotipe hibrida: H1, H2, H3, H4, H6, H7, H8, H9, H10, H11, H12, H13, H14; 4 genotipe tetua: IPB G1, IPB G30, IPB M21, IPB M23; dan varietas pembanding: Alisha F1. Percobaan I disusun dengan rancangan kelompok lengkap teracak (RKLT) faktor tunggal, sedangkan percobaan kedua disusun dengan rancangan kisi alfa faktor tunggal. Hibrida H4 unggul pada karakter bobot buah, bobot buah per plot, dan padatan terlarut total, sedangkan H9 unggul pada karakter warna dan rasa daging buah, serta ukuran buah. Heterosis dan heterobeltiosis tertinggi dimiliki oleh hibrida H7, H10, dan H14. Galur IPB M23 dan IPB G30 berpotensi sebagai tetua untuk perakitan varietas unggul., Improving the quality of melons can be conducted by developing improved hybrid varieties based on heterosis phenomenon. This study aimed to identify the potential melon genotypes with good fruit quality and evaluate the characters of the hybrids. The research was conducted in a greenhouse at the Cikabayan Experimental Station of the IPB University, Bogor from November 2020 to March 2021 and in an open field in Tanjungsari Village, Jogorogo, Ngawi, East Java from April to July 2021. The genetic materials for the first experiment were IPB G30, IPB G1, IPB M23, IPB M21, and one commercial hybrid variety as a check (Alisha F1). The genetic materials for the second experiment were 13 hybrid genotypes: H1, H2, H3, H4, H6, H7, H8, H9, H10, H11, H12, H13, H14; four parental genotypes: IPB G1, IPB G30, IPB M21, IPB M23; and Alisha F1 as a check. The first experiment was arranged using a single factor randomized complete block design (RCBD), while a single factor alpha lattice design was used for the second experiment. The H4 hybrid had good fruit traits, while H9 had good flesh color and taste, and ideal fruit size. The H7, H10, and H14 hybrids had the highest mid parent and best parent heterosis. The IPB M23 and IPB G30 had the potential to be used as parents for breeding improved varieties.
Keyword: heterosis, hibridisasi, kualitatif, kuantitatif, varietas hibrida

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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