Host plant preference amongst several fruit species was studied for two fruit fly species i.e. Bactrocera carambolae (Drew & Hancock) and Bactrocera dorsalis (Drew & Hancock), which both belong to B. dorsalis species complex. Both fruit fly species are known to be polyphagous and cause significant economic losses as pests of fruit crops. The aim of this research was to assess the host range of these major pests in Indonesia. The research was conducted at the Entomology Laboratory and Insect Specimen Collection Laboratory, Indonesian Center for Agriculture Biotechnology and Genetic Resource Research and Development, Bogor, West Java, Indonesia from June 2011 to March 2012. Comparative host preference for both species was studied with regard to malaya varieties of star fruit (Averrhoa carambolae), manalagi varieties of mango (Mangifera indica), guava aka water apple (Psidium guajava), citra water guava (Eugenia aquae), jamaica bol guava (Eugenia malaccenensis), and california papaya (Carica papaya). Our results suggest the strongest preference for malaya star fruit by B. carambolae followed by manalagi mango; and for california papaya followed by manalagi mango by B. dorsalis. The study also found that welahan variety star fruit is least preferred by both species of fruit fly.

<p class="abstrakinggris">Increasing productivity of soybean has often been constrained by pod sucking bugs (<em>Riptortus</em> spp.) which caused a serious damage  and yield losses up to 80%. Breeding for obtaining soybean variety resistant to pod suckers needs the availability of soybean germplasm resistant to the pest. The study aimed to obtain a candidate for soybean variety resistant to Riptortus spp. through the selection of 100 accessions of soybean. The study included the preparation of test plants and test insects, pest infestations, observations, and looking for a practical screening method for pod sucking pests. The experiment used a completely randomized design for two treatments (infested and non-infested <em>Riptortus</em> spp.). Cikuray variety and PI-092734 accession were used as a control. Results showed that there was a very low correlation among variables observed. Twelve soybean accessions showed a resistance to <em>Riptortus </em>spp., i.e. C7301-113AC-POP, Lokal Madiun-3549, Lokal Klungkung, ML.2974, Singgalang, Lokal Jepara, Lokal Jatim, Lokal Trenggalek, Lokal Tulungagung, Lokal Tabanan, Lokal Blitar, and Lokal Kuningan 10. These accessions were more resistant than the popular released variety such as Wilis, Grobogan, Detam 2, and Gepak Ijo. Small seed size was not a major determinant of soybean resistance to pod suckers. The addition of observational components, i.e. probing preference and oviposition, indicated that crop damage was indirectly influenced by the high frequency of probing and oviposition, although its relation to plant tolerant mechanisms still needs further investigation. Indeterminate plant types require further validation as to whether they contribute significantly to plant resistance against pod sucking insects.</p>

<p>Biji sorgum dimanfaatkan sebagai sumber pangan, pakan dan bahan industri. Batang tanaman sorgum umumnya mengandung senyawa gula, sehingga dapat dimanfaatkan sebagai minuman sirup dan bahan baku bioethanol. Untuk mengetahui kandungan senyawa gula pada batang tanaman sorgum dapat dilakukan dengan mengukur kadar brix dengan alat refraktometer. Untuk menghasilkan varietas sorgum yang dapat menghasilkan brix tinggi diperlukan sumber genetik untuk pemuliaan tanaman sorgum. Penelitian telah dilaksanakan terhadap 219 aksesi plasma nutfah sorgum koleksi Bank Gen Balitbangtan di BB Biogen. Bahan batang tanaman diperoleh dari pertanaman sorgum yang ditanam pada tahun 2017. Sampel batang tanaman sorgum dipotong menjadi 3 bagian yang sama panjangnya dan diukur kandungan brix dengan refraktometer. Hasil penelitian menunjukkan aksesi plasma nutfah sorgum dari batang bagian bawah, tengah dan atas memiliki kandungan brix bervariasi yaitu berkisar antara 0.2 – 15.1 %. Aksesi sorgum introduksi ICSV 93051, ICSV 93032, ICSV 93047, ICSR 91026, ICSV 8906, dan ICSV 93007 memiliki kandungan brix lebih dari 14% yang dapat dipergunakan sebagai bahan pemuliaan sorgum manis. Genotipe yang memiliki sifat ganda yang mampu menghasilkan hasil biji dan kandungan brix baik pada tanaman induk maupun ratun perlu mendapat perhatian.</p><p> </p><p> </p><p align="center"><strong>Abstract</strong><strong></strong></p><p align="center"><strong> </strong></p><p>       Sorghum seeds are used as a source for food, feed, and industrial materials. Stems of sorghum plants generally contain sugar compounds, so it can be used as a beverage of syrup and raw materials of bioethanol. The content of sugar compounds on the stem of the sorghum plant could be done by measuring brix by using refractometer. Genetic resources are needed to develop sorghum varieties that can produce high brix content in its plant breeding program. A study has been conducted on 219 germplasm accessions of IAARD Gene Bank collection at BB BIOGEN. The plant stem material is derived from the planting of sorghum grown in 2017. The stem of the sorghum plant is cut into 3 equal lengths and brix content measured by refractometer. The results showed that the accession of the sorghum germplasm from the lower, middle, and upper stems reveal that brix content varied from 0.2 to 15.1%. Introduction accession of sorghum i.e. ICSV 93051, ICSV 93032, ICSV 93047, ICSR 91026, ICSV 8906, and ICSV 93007 had a brix content of more than 14% and can be used as parent materials for sweet sorghum breeding. Multiple traits of genotipe which are capable producing seed yield and brix content in both primary plants and ratoon need further attention.</p><p> </p><p><strong><em><br /></em></strong><em></em></p>

<p>Dioscorea spp. merupakan tanaman umbi-umbian yang termasuk dalam kategori pangan fungsional karena mengandung senyawa bioaktif, di antaranya ialah diosgenin. Senyawa ini merupakan senyawa golongan steroid saponin digunakan sebagai bahan baku dalam sintesis obat golongan steroid. Sumber utama senyawa diosgenin adalah Dioscorea spp. Indonesia sebagai salah satu center of origin Dioscorea berpeluang untuk menjadi produsen diosgenin dunia karena mempunyai beragam plasma nutfah Dioscorea. Oleh sebab itu, perlu dikaji potensi diosgenin dari Dioscorea spp. lokal Indonesia. Dalam penelitian ini dilakukan karakterisasi kuantitatif senyawa diosgenin menggunakan metode spektrofotometri Ultra Violet-Visible (UV-Vis) pada 26 aksesi Dioscorea spp. lokal Indonesia, terdiri atas 10 aksesi D. alata, 7 aksesi D. esculenta, dan 9 aksesi D. hispida. Validasi metode spektrofotometri UV-Vis ditentukan berdasarkan nilai korelasi linear, LOD, dan LOQ. Ekstraksi diosgenin dilakukan dengan refluks dan<br />hidrolisis pada saat yang bersamaan dengan pelarut isopropanol 70% dan H2SO4 20%. Metode UV-Vis yang digunakan dalam penelitian ini cukup sensitif dan akurat dengan nilai korelasi linear 0,996, LOD 2,604 μg, dan LOQ 7,890 μg. Kandungan diosgenin tertinggi diperoleh dari aksesi D. hispida dengan kode II sebesar 0,294%. D. hispida dapat dimanfaatkan sebagai kandidat sumber potensial senyawa diosgenin.</p>

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