Judul: Studi Poliembrioni, Viabilitas Benih dan Identifikasi Genetik Semaian Jeruk Japansche Citroen (Citrus limonia Osbeck.) menggunakan SSR
Abstrak: Japansche Citroen (Citrus limonia Osbeck) or JC is citrus rootstock that is often used by Indonesian citrus farmer because its wide adaptation ability and has resistant to several diseases. JC seeds should have physical, physiological, genetic and health quality. Seed has maximum quality when it is reached at the time of physiological maturity. Seed maturity, in general is decided by physical appearance of fruit, such as rind colour changes. JC seeds have polyembryony characteristic; threrefore one or more embryos per seed consist of either zygotic embryo and or nucellar embryo. Nucellar embryo can be useful for clonal propagation. Nevertheles, there were off type seedling. It is necessary to identify seedling base on morphology and molecular marker such as SSR marker. Morphology marker was easy to used and cheap, but the trully genetic must be identify with SSR. SSR could differenciate between homozygot and heterozigot genotype. The aims of this research were to acquire information about poliembryony on JC citrus, to determine physiological maturity of JC seed base on rind colour and fruit hardness, to know the effect of fruits maturity to physical and physiological quality of seed, genetic quality and number of seedling, and to identify JC seedling base on morphology marker and SSR marker. The research was conducted in Indonesian Citrus and Subtropical Fruits Research Institute from April 2012 to January 2013. The research consisted of three experiments, there were 1) study on polyembryony of JC , 2) study on effect of fruits maturity level to physical and physiological quality of seed, genetic quality and number of seedling, and 3) identification of JC seedling base on morphology marker and SSR marker. Experiment I was conducted based on visual observations on each of 30 seeds of five maturity levels. Criteria of fruit maturity are 1) dark green rind, hard fruit (> 7 kg/cm2), 2) green yellow rind, rather hard (6-7 kg/cm2), 3) pieces of yellowish green rind, rather soft (5-5.9 kg/cm2), 4) >90% yellow rind, soft (4-4.9 kg/cm2) and 5) pieces of yellow-orange rind, very soft (< 4 kg/cm2). The experiment variable were seed coat colour, the mean number of embryos per seed, polyembryony seed percentage (%) and the dominant colour of the embryo. Experiment II used randomized completely block design (RCBD) one factor. The factor is five maturity level base on fruits maturity. The criteria of fruits maturity are equal to experiment I. Each treatment was repeated three times so that there was 15 units of experiments with experimental unit consisted of 100 seeds. The experiment variable were seed moisture content (%), dry weight of 10 seeds (g), vigor index (%), seed growth rate (%/etmal), germination percentage (%), the growth percentage (%), multiple seedling percentage (%), total seedlings, off type seedling percentage (%), and total true to type seedling. Data were analyzed with analysis of variance (ANOVA). If the results obtained by analysis of variance were significant different, then tested by Duncan's Multiple Range Test (DMRT) at 5% level. Experiment III was the identification of true to type seedlings and off type seedling with morphology marker and molecular markers. This experiment
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