Judul: Pengaruh NaCl dan KCl terhadap pertumbuhan pseudomos solanacearum E.F.SM.IN vitro dan bibit cengkeh
Abstrak: Penelitian ini bertujuan mengetahui pengaruh garam NaCl dan KCl terhadap pertumbuhan bakteri P. solanacearum in vitro dan terhadap bibit cengkeh. Diharapkan dari hasil penelitian ini diperoleh suatu angka konsentrasi NaCl ataupun KCl yang paling efektif untuk menghambat pertumbuhan P. solanacearum. Di samping itu untuk mengetahui sampai dosis berapa bibit cengkeh toleran terhadap pemberian NaCl ataupun KCl. Diharapkan garam- garam tersebut dapat digunakan sebagai pemberantas patogen P. solanacearum yang menyebabkan penyakit layu pada tanaman cengkeh.
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Judul: Faktor-faktor yang Berpengaruh terhadap Pertumbuhan Ralstonia solanacearum Yabuuchi et al. dalam Tanah
Abstrak: Ralstonia solanacearum merupakan bakteri penyebab layu pada tanaman pangan dan hortikultura. Keragaman genetik patogen ini ditunjukkan dengan kemampuannya membentuk strain baru yang berbeda ciri-cirinya dari strain asal, misalnya strain yang berbeda virulensi serta reaksi fisiologi dan biokimianya. Faktor-faktor yang menghambat pertumbuhan R. solanacearum pada rotasi kentang dengan tanaman bukan inang belum banyak diketahui. Penelitian ini bertujuan untuk mengetahui faktor-fak.tor yang mempengaruhi pertumbuhan R. solanacearum dalam tanah. Dua puluh tujuh isolat bakteri dan cendawan diuji potensi antagonistiknya terhadap R. solanacearum. Enam isolat bakteri memiliki daya antagonistik paling potensial terhadap R. so/anacearum, yaitu PSB 10 (16,11 mm), PSB 11 (15,40 mm), PSB 12 (17,00 mm), LBB 02 (15,92 mm), LBB 06 (15,75 mm), dan CKB 20 (15,94 mm), sedangkan dua betas isolat bakteri lainnya menunjukkan daya antagonistik potensial. Tiga isolat cendawan memiliki daya antagonistik paling potensial terhadap R. solanacearum, yaitu LBC 06 (16,40 mm), LBC 07 (25,45 mm), dan PSC 09 (16,83 mm), sedangkan lima belas isolat cendawan lainnya rnenunjukkan daya antagonistik potensial. Persentase isolat bak.teri dan cendawan antagonis paling tinggi dijumpai pada rizosfer tanaman jagung (37,04%). Filtrat akar jagung dapat menghambat pertumbuhan R. solanacearum dengan zona hambat berkisar antara 17,08-26,17 mm. Demikian juga filtrat akar soba dapat menyebabkan penghambatan pertunbuhan R. so/anacearum dengan zona hambat berkisar antara 8,28-13,60 mm. Penggunaan mikoriza Glomus manihotis cenderung menurunkan populasi R. solanacearum dalam tanah yang ditanami jagung dan penurunan populasinya dimulai dari hari ke 45 sampai 60 hari setelah tanam.
Keyword: ralstonia solanacearum, bakteri dan cendawan antagonis, penghambatan pertumbuhan, cendawan antagonis, jagung dan soba

Judul: Identifikasi Molekuler Kompleks Spesies Himantura uarnak (Batoidea: Dasyatidae) di Indonesia.
Abstrak: Stingrays are one of the cartilaginous fish, apart of sharks and skates, and one of Indonesia's fishery resources. Almost of elasmobranch fishes are economically important fish. The refined products and live specimens of this fish are a lot of traded. Himantura uarnak, H. undulata and H. leoparda are stingray species in Himantura and Dasyatidae family, which are the most popular stingrays in Indonesia waters. The stingrays are major target species were used as a consumable product and trading products. Levels of species diversity of cartilaginous fish in Indonesia are very high, and also Indonesia is listed as one of the countries that use elasmobranch resources the highest in the world. Generally, this study aims to identify each species of H. uarnak species complex through molecular approaches. While specifically, this study aims to estimate the evolutionary process of species divergence and to determine the relationship between species. The methods were used in this study included field sampling, sample collection, and specimen identification, collection of genetic samples, analysis of genetic samples and data analysis . Size polymorphism nuclear DNA markers (intron EPIC) were used. Polymorphism alleles translated into genotypes and alleles frequency of five introns loci. The results of Bayesian analysis and Correspondence Analysis (CA) produced informative diagram of the population structure showed 4 different clusters. Cluster 1 and 4 were H. leoparda, Cluster 2 indicated as H. undulata and the Cluster 3 was H. uarnak. Cluster 1 was a variant of Cluster 4, in this time called as H. leoparda var.1. Separation of four clusters according to nuclear DNA need to be proved by mitochondria DNA maker by cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b). Molecular approaches were using mitochondrial DNA gene cytochrome c oxidase subunit I (COI) and cytochrome b produced 4 main groups (Group I, II, III and IV). Both of these molecular approaches showed each individual of groups were in consistent clade and the main group. Hence the H. uarnak species complex in Indonesian waters were divided into 4 main groups, and each was a particular species. The Group I and IV were the two group species that have been released as H. leoparda and Group I was H. leoparda var. 1 identified as cryptic species. Group II was one individual who grouped as H. undulata. Group III was one of other group that identified as H. uarnak and in accordance with the morphological characteristic through spotting pettern. Morphological approach to identified the stingrays of Himantura uarnak species complex clearly less accurate than the molecular approaches. Morphological approach should not be used to identify a species complex in stingrays without helped by other approaches.
Keyword: Himantura uarnak species complex, intron EPIC, cyt b, COI, spotting pattern