Istianto, M., K. Untung, Mulyadi, Y. A. Trisyono, and T. Yuwono. 2004.
Key words: Essential oil; Sweet orange; Pumello; Panonychus citri; Development;
Diposting oleh Dr.Ir.Mizu Istianto, MT. di 9:20 PM
Oleh : Dr.Ir. Mizu Istianto, MT.
Hama penggerek buah jeruk (Citripestis sagittiferela) menyebabkan kerugian cukup besar bagi petani jeruk terutama untuk jeruk manis (sweet orange) dan jeruk besar (pumello). Buah yang terserang hama ini tidak bisa dikonsumsi karena daging buah busuk. Beberapa teknik pengendalian yang ada masih belum memberikan hasil yang memuaskan. Walaupun demikian, telah ditemukan penggunaan bahan penolak (repellent) yang mampu menekan tingkat serangan hama ini. Produk bahan penolak tersebut merupakan formulasi minyak atsiri tumbuhan yang tidak disukai hama ini. Penggunaan bahan penolak ini mampu menekan tingkat serangan antara 60-80%.
Diposting oleh Dr.Ir.Mizu Istianto, MT. di 10:45 PM
Evaluation of Essential Oils for Antifungal Activity Against Antracnose Disease (Colletotrichum sp) Attacks Banana Fruit in Strorage
for more information e-mail : Ir_Mizu@yahoo.co.id
Antracnose, caused by Colletotrichum sp, is important disease that attack banana fruit in storage. The technologies recommended to control antracnose are applying fungicides and heat treatment. Although these fungicides control antracnose effectively, they have negative effect to consumer especially in healthy. Alternative technologies that consider the safety of consumer and environment are needed to replace fungicide application. Essential oils have long been recognized as having good fungitoxic compounds. The aim of this experiment was to understand antifungal activity of essential oils extracted from Cinnamomum bumanni, Cymbopogon nardus, and Citrus grandis against antracnose disease. The experimant was conducted in laboratory of Indonesian Tropical Fruit Resesearch Institute at room temperature. The result showed that essential oils had negative effect to the growth of Colletotrichum sp’s mycelial. Essential oil extracted from C. bumanni had highest inhibition value (65-72%) to the mycelial growth of Colletotrichum sp, followed with inhibition value of C. nardus (62-64%) and C. grandis (14-19%) at last observation. These results showed that essential oil had good potency to be developed as alternative technology that considered consumer and environment safety. The next research to evaluate these essential oil at lower temperature (cold storage) was suggested to be conducted because of distribution banana fruits for long distance usually use cold storage.
[Keywords: essential oils; Cinnamomum bumanni; Cymbopogon nardus; Citrus grandis; Colletotrichum sp; antifungal activity]
(a) (b) (c) (d)
Fig. 1. Mycelial growth of Colletotricum sp treated with essential oil of C. bumanni (a), C. nardus (b), C. grandis (c), and untreated
Diposting oleh Dr.Ir.Mizu Istianto, MT. di 12:00 PM
From Wikipedia, the free encyclopedia
Drosophila melanogaster (from the Greek for black-bellied dew-lover) is a two-winged insect that belongs to the Diptera, the order of the flies. The species is commonly known as the fruit fly, and is one of the most commonly used model organisms in biology, including studies in genetics, physiology and life history evolution. Flies belonging to the Tephritidae are also called fruit flies, which can lead to confusion.
Wildtype fruit flies have red eyes, are yellow-brown in colour, and have transverse black rings across their abdomen. They exhibit sexual dimorphism: females are about 2.5 millimetres (0.1 inches) long; males are slightly smaller and the back of their bodies are darker. Males are easily distinguished from females based on colour differences (males have a distinct black patch at the abdomen, less noticeable in recently emerged flies (see fig)) and the sexcombs (a row of dark bristles on the tarsus of the first leg). Furthermore, males have a cluster of spiky hairs (claspers) surrounding the anus and genitals used to attach to the female during mating.
There are extensive images at Fly Base.
The developmental period for Drosophila melanogaster varies with temperature, as with many ectothermic species. The shortest development
time (egg to adult), 7 days, is achieved at 28 °C. Development times increase at higher temperatures (30 °C, 11 days) due to heat stress. Under ideal conditions, the development time at 25 °C is 8.5 days , at 18 °C it takes 19 days and at 12 °C it takes over 50 days. Under crowded conditions, development time increases , while the emerging flies are smaller. Females lay some 400 eggs (embryos), about five at a time, into rotting fruit or other suitable material such as decaying mushrooms and sap fluxes. The eggs, which are about 0.5 millimetres long, hatch after 12–15 h (at 25 °C). The resulting larvae grow for about 4 days (at 25 °C) while molting twice (into 2nd- and 3rd-instar larvae), at about 24 and 48 h after eclosion. During this time, they feed on the microorganisms that decompose the fruit, as well as on the sugar of the fruit themselves. Then the larvae encapsulate in the puparium and undergo a four-day-long metamorphosis (at 25 °C), after which the adults eclose (emerge).
Females become receptive to courting males at about 8-12 hours after emergence. Males perform a sequence of five behavioral patterns to court females. First, males orient themselves while playing a courtship song by horizontally extending and vibrating their wings. Soon after, the male positions itself at the rear of the female's adbdomen in a low posture to tap and lick the female genitalia. Finally, the male curls its abdomen, and attempts copulation. Females can reject males by moving away and extruding their ovipositor. The average duration of successful copulation is 30 minutes, during which males transfer a few hundred very long (1.76mm) sperm cells in seminal fluid to the female. Females store the sperm, which may need to compete with other males' stored sperm to fertilize eggs.
The D. melanogaster lifespan is about 30 days at 29 °C.
Charles W. Woodworth is credited with being the first to breed Drosophila in quantity and for suggesting to W. E. Castle that they might be used for genetic research during his time at Harvard University. Beginning in 1910, fruit flies helped Thomas Hunt Morgan accomplish his studies on heredity. "Thomas Hunt Morgan and colleagues extended Mendel's work by describing X-linked inheritance and by showing that genes located on the same chromosome do not show independent assortment. Studies of X-linked traits helped confirm that genes are found on chromosomes, while studies of linked traits led to the first maps showing the locations of genetic loci on chromosomes" (Freman 214). The first maps of Drosophila chromosomes were completed by Alfred Sturtevant.
The genome of D. melanogaster (sequenced in 2000, and curated at the FlyBase database) contains four pairs of chromosomes: an X/Y pair, and three autosomes labeled 2, 3, and 4. The fourth chromosome is so tiny that it is often ignored, aside from its important eyeless gene. Its sequenced genome of ~132 million bases has been annotated and contains approximately 13,767 protein-coding genes which comprise ~20% of the genome. More than 60% of the genome appears to be functional non-protein-coding DNA involved in gene expression control. Determination of sex in Drosophila occurs by the ratio of X chromosomes to autosomes, not because of the presence of a Y chromosome as in human sex determination.
Drosophila genes are traditionally named after the phenotype they cause when mutated. For example, the absence of a particular gene in Drosophila will result in a mutant embryo that does not develop a heart. Scientists have thus called this gene tinman, named after the Oz character of the same name (Cf. Azpiazu & Frasch (1993) Genes and Development: 7: 1325-1340.). This system of nomenclature results is a wider range of gene names than in other organisms.
About 75% of known human disease genes have a recognizable match in the genetic code of fruit flies (Reiter et al (2001) Genome Research: 11(6):1114-25), and 50% of fly protein sequences have mammalian analogues. An online database called Homophila  is available to search for human disease gene homologues in flies and vice versa. Drosophila is being used as a genetic model for several human diseases including the neurodegenerative disorders Parkinson's, Huntington's, Spinocerebellar ataxia and Alzheimer's disease. The fly is also being used to study mechanisms underlying immunity, diabetes, and cancer, as well as drug abuse.
Embryogenesis in Drosophila has been extensively studied, as its small size, short generation time, and large brood size makes it ideal for genetic studies. It is also unique among model organisms in that cleavage occurs in a syncytium.
During oogenesis, cytoplasmic bridges called "ring canals" connect the forming oocyte to nurse cells. Nutrients and developmental control molecules move from the nurse cells into the oocyte. In the figure to the left, the forming oocyte can be seen to be covered by follicular support cells.
After fertilization of the oocyte the early embryo or (syncytial embryo) undergoes rapid DNA replication and 13 nuclear divisions until approximately 5000 to 6000 nuclei accumulate in the unseparated cytoplasm of the embryo. By the end of the 8th division most nuclei have migrated to the surface, surrounding the yolk sac (leaving behind only a few nuclei, which will become the yolk nuclei). After the 10th division the pole cells form at the posterior end of the embryo, segregating the germ line from the syncytium. Finally, after the 13th division cell membranes slowly invaginate, dividing the syncytium into individual somatic cells. Once this process is completed gastrulation starts.
Nuclear division in the early Drosophila embryo happens so quickly there are no proper checkpoints so mistakes may be made in division of the DNA. To get around this problem the nuclei which have made a mistake detach from their centrosomes and fall into the centre of the embryo (yolk sac) which will not form part of the fly.
The gene network (transcriptional and protein interactions) governing the early development of
the fruitfly embryo is one of the best understood gene networks to date, especially the patterning along the antero-posterior (AP) and dorso-ventral (DV) axes (See under morphogenesis).
The embryo undergoes well-characterized morphogenetic movements during gastrulation and early development, including germ-band extension, formation of several furrows, ventral invagination of the mesoderm, posterior and anterior invagination of endoderm (gut), as well as extensive body segmentation  until finally hatching from the surrounding cuticle into a 1st-instar larva.
During larval development, tissues known as imaginal discs grow inside the larva. Imaginal discs develop to form most structures of the adult body, such as the head, legs, wings, thorax and genetalia. Cells of the imaginal disks are set aside during embryogenesis and continue to grow and divide during the larval stages - unlike most other cells of the larva which have differentiated to perform specialized functions and grow without further cell division. At metamorphosis, the larva forms a pupae, inside which the larval tissues are reabsorbed and the imaginal tissues undergo extensive morphogenetic movements to form adult structures.
In 1971, Ron Konopka and Seymour Benzer published "Clock mutants of Drosophila melanogaster", a paper describing the first mutations that affected an animal's behavior. Wild-type flies show an activity rhythm with a frequency of about a day (24 hours). They found mutants with faster and slower rhythms as well as broken rhythms - flies that move and rest in random spurts. Work over the following 30 years has shown that these mutations (and others like them) affect a group of genes and their products that comprise a biochemical or biological clock. This clock is found in a wide range of fly cells, but the clock-bearing cells that control activity are several dozen neurons in the fly's central brain.
Since then, Benzer and others have used behavioral screens to isolate genes involved in vision, olfaction, audition, learning/memory, courtship, pain and other processes, such as longevity.
The first learning and memory mutants (dunce, rutabaga etc) were isolated by William "Chip" Quinn while in Benzer's lab, and were eventually shown to encode components of an intracellular signalling pathway involving cylic AMP, protein kinase A and a transcription factor known as CREB. These molecules were shown to be also involved in synaptic plasticity in Aplysia and mammals.
Male flies sing to the females during courtship using their wing to generate sound, and some of the genetics of sexual behavior have been characterized. In particular, the fruitless gene has several different splice forms, and male flies expressing female splice forms have female-like behavior and vice-versa.
Furthermore, Drosophila has been used in neuropharmacological research, including studies of cocaine and alcohol consumption.
The compound eye of the fruit fly contains 800 unit eyes or ommatidia,
and are one of the most advanced among insects. Each ommatidium contains 8 photoreceptor cells (R1-8), support cells, pigment cells, and a cornea. Wild-type flies have reddish pigment cells, which serve to absorb excess blue light so the fly isn't blinded by ambient light.
Each photoreceptor cell consists of two main sections, the cell body and the rhabdomere. The cell body contains the nucleus while the 100-μm-long rhabdomere is made up of toothbrush-like stacks of membrane called microvilli. Each microvillus is 1–2 μm in length and ~60 nm in diameter. The membrane of the rhabdomere is packed with about 100 million rhodopsin molecules, the visual protein that absorbs light. The rest of the visual proteins are also tightly packed into the microvillar space, leaving little room for cytoplasm.
The photoreceptors in Drosophila express a variety of rhodopsin isoforms. The R1-R6 photoreceptor cells express Rhodopsin1 (Rh1) which absorbs blue light (480 nm). The R7 and R8 cells express a combination of either Rh3 or Rh4 which absorb UV light (345 nm and 375 nm), and Rh5 or Rh6 which absorb blue (437 nm) and green (508 nm) light respectively. Each rhodopsin molecule consists of an opsin protein covalently linked to a carotenoid chromophore, 11-cis-3-hydroxyretinal. 
As in vertebrate vision, visual transduction in invertebrates occurs via a G protein-coupled pathway. However, in vertebrates the G protein is transducin, while the G protein in invertebrates is Gq (dgq in Drosophila). When rhodopsin (Rh) absorbs a photon of light its chromophore, 11-cis-3-hydroxyretinal, is isomerized to all-trans-3-hydroxyretinal. Rh undergoes a conformational change into its active form, metarhodopsin. Metarhodopsin activates Gq, which in turn activates a phospholipase Cβ (PLCβ) known as NorpA.
PLCβ hydrolyzes phosphatidylinositol (4,5)-bisphosphate (PIP2), a phospholipid found in the cell membrane, into soluble inositol triphosphate (IP3) and diacylgycerol (DAG), which stays in the cell membrane. DAG or a derivative of DAG causes a calcium selective ion channel known as TRP (transient receptor potential) to open and calcium and sodium flows into the cell. IP3 is thought to bind to IP3 receptors in the subrhabdomeric cisternae, an extension of the endoplasmic reticulum, and cause release of calcium, but this process doesn't seem to be essential for normal vision. 
Calcium binds to proteins such as calmodulin (CaM) and an eye-specific protein kinase C (PKC) known as InaC. These proteins interact with other proteins and have been shown to be necessary for shut off of the light response. In addition, proteins called arrestins bind metarhodopsin and prevent it from activating more Gq.
TRP, InaC, and PLC form a signaling complex by binding a scaffolding protein called InaD. InaD contains five binding domains called PDZ domains which specifically bind the C termini of target proteins. Disruption of the complex by mutations in either the PDZ domains or the target proteins reduces the efficiency of signaling. For example, disruption of the interaction between InaC, the protein kinase C, and InaD results in a delay in inactivation of the light response.
Approximately two-thirds of the Drosophila brain (about 200,000 neurons total) is dedicated to visual processing. Although the spatial resolution of their vision is significantly worse than that of humans, their temporal resolution is approximately ten times better.
The wings of a fly are capable of beating at up to 220 times per second. Flies fly via straight sequences of movement interspersed by rapid turns called saccades. During these turns, a fly is able to rotate 90 degrees in fewer than 50 milliseconds.
Drosophila, and probably many other flies, have optic nerves which lead directly to the wing muscles (while in other insects they always lead to the brain first), making it possible for them to react extremely quickly.
It was long thought that the characteristics of Drosophila flight were dominated by the viscosity of the air, rather than the inertia of the fly body. However, research in the lab of Michael Dickinson has indicated that flies perform banked turns, where the fly accelerates, slows down while turning, and accelerates again at the end of the turn. This indicates that inertia is the dominant force, as is the case with larger flying animals.
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When two Drosophila melanogaster of the opposite sex encounter one another, they often first exhibit "cleaning behavior". After this behavior is engaged for some time, the male will proceed towards the rear of the female from either the left or right side. He will then begin a "dance" in which he describes a semi-circle around the female. During this dance the male may or may not vibrate his wings. If the female is not receptive, she will move away and courtship ends. If she is receptive however, the male will approach her rear and make contact with her using his proboscis. The female may then scissor her wings and allow the male to mount. When intercourse, which usually takes about 30 minutes, has finished, the female will dislodge the male with a violent kicking of her hind legs.
Diposting oleh Dr.Ir.Mizu Istianto, MT. di 1:11 AM
Sumber : www.iptek.net.id
Family : Anacardiaceae
Mangga - yang berasal dari daerah Probolinggo, Jawa Timur - ini merupakan salah satu varietas unggul yang telah dilepas oleh Menteri Pertanian. Buahnya berbentuk jorong, berparuh sedikit, dan ujungnya meruncing. Pangkal buah berwarna merah keunguan, sedangkan bagian lainnya berwarna hijau kebiruan. Kulitnya tidak begitu tebal, berbintik-bintik kelenjar berwarna keputihan, dan ditutupi lapisan lilin. Daging buahnya tebal, berwarna kuning, lunak, tak berserat, dan tidak begitu banyak mengandung air. Rasanya manis segar, tetapi pada bagian ujungnya kadan:gkadang terasa asam. Bijinya kecil, lonjong pipih, dan panjangnya antara 13-14 cm. Panjang buahnya dapat mencapai 15 cm dengan berat rata-rata per buah 450 g. Produktivitasnya cukup tinggi, dapat mencapai 54 kg/pohon.
Diposting oleh Dr.Ir.Mizu Istianto, MT. di 8:31 PM