Xanthomonas oryzae pv. oryzae (Xoo), a causal agent of bacterial leaf blight (BLB), is one of the most important pathogens of rice. The effectiveness of ten Streptomyces spp. isolates in suppressing Xoo disease was assessed in planta and in vitro. In planta experiments were carried out in a greenhouse and arranged in a randomized completely block design (RCBD) with three replications. Twenty treatments were tested which included plants inoculated with both Streptomyces spp. and Xoo, and plants inoculated with only Streptomyces spp. Plants inoculated with Xoo and sprayed with a chemical bactericide, and plants inoculated with only Xoo served as positive controls, whereas plants not inoculated with either Streptomyces spp. or Xoo were used as negative controls. The results showed that the effect of endophytic Streptomyces spp. on BLB disease expressed as area under disease progress curve (AUDPC) was not significantly different to that on control plants (P > 0.05). However, plants inoculated with endophytic Streptomyces spp. were significantly taller and produced higher tiller number than control plants (P < 0.05). Streptomyces spp. isolate AB131-1 gave the highest plant height. In vitro studies on biocontrol mechanisms of selected Streptomyces spp. isolates showed that isolate LBR02 gave the highest inhibition activity on Xoo growth, followed by AB131-1 and AB131-2. Two isolates (AB131-1 and LBR02) were able to produce chitinase, phosphatase, and siderophore which included biocontrol characteristics. Morphological and colonization studies under SEM and light microscopy confirmed that the three isolates were endophytic Streptomyces spp. from different species. These studies found that the paddy plant which was inoculated with endophytic Streptomyces spp. AB131-1 and infected by Xoo could increase the height of plant and number of tillers.

Six actinomycete strains isolated from soil and plant-litter samples in Indonesia were studied for their taxonomic position by using a polyphasic approach. Phylogenetically, all the strains were located in the broad cluster of the genus Actinokineospora. Chemotaxonomic data [cell-wall diamino acid, meso-diaminopimelic acid; cell-wall peptidoglycan, type III (A1γ); major sugars, galactose and arabinose; major menaquinone, MK-9(H4); major fatty acid, iso-C16 : 0; major phospholipid, phosphatidylethanolamine] supported the affiliation of all six strains to the genus Actinokineospora. The results of DNA–DNA hybridization with DNA from type strains of Actinokineospora species with validly published names revealed three DNA–DNA relatedness groups. Group I (ID03-0561T) showed low relatedness to the other strains studied. The three strains in group II (ID03-0784T, ID03-0808 and ID03-0809) formed a group with high relatedness (98–100 %) and showed low relatedness to the other strains studied. The two strains in group III (ID03-0810T and ID03-0813) showed 58–68 % relatedness to Actinokineospora terrae NBRC 15668T and showed low relatedness (2–24 %) to the other strains studied. The description of three novel species is proposed: Actinokineospora baliensis sp. nov., for the single strain in group I (type strain ID03-0561T =BTCC B-554T =NBRC 104211T), Actinokineospora cibodasensis sp. nov., for the strains in group II (type strain ID03-0784T =BTCC B-555T =NBRC 104212T), and Actinokineospora cianjurensis sp. nov., for the strains in group III (type strain ID03-0810T =BTCC B-558T =NBRC 105526T).

The taxonomic positions of actinomycete strains T and ID03-0825, isolated from soil on the Indonesian island of Bali, were examined using a polyphasic taxonomic approach. The morphological and chemotaxonomic characteristics of these organisms are typical of the genus Streptomyces. Phylogenetic analyses performed using almost-complete 16S rRNA gene sequences demonstrated that the strains were closely related to Streptomyces glauciniger and Streptomyces lilacinus. However, DNA-DNA hybridization and phenotypic characteristics revealed that the strains differed from known Streptomyces species. Therefore, we conclude that strains ID03-0915 T and ID03-0825 (5BTCC B-563) represent a novel species of the genus Streptomyces, for which we propose the name Streptomyces baliensis sp. nov. The type strain is strain ID03-0915 T (5BTCC B-608 T 5NBRC 104276 T ).

Sorghum (Sorghum bicolor) and soybean (Glycines o r g h u m ; s o y b e a n ; l a n d productivity. AbstrakPenanaman sorgum (Sorghum bicolor) dan kedelai (Glycine max) sebagai tanaman tumpangsari merupakan pilihan yang tepat untuk mendukung upaya pengembangan pertanian berkelanjutan dan peningkatan produksi pangan Indonesia. Lahan karet belum menghasilkan cukup luas untuk dimanfaatkan untuk upaya tersebut. Penelitian ini bertujuan untuk mendapatkan pola tanam tumpangsari yang tepat dan melihat interaksinya terhadap tanaman karet baik dalam hal penyebaran penyakit jamur akar putih dan kesuburan tanah. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) dengan dua faktor perlakuan dengan tiga ulangan. Faktor perlakuan yang digunakan yaitu jarak tanaman tumpangsari 0,5 m, 1 m dan 1,5 m terhadap tanaman karet, dan jenis tanaman tumpangsari yaitu sorgum dan kedelai. Penelitian dilakukan di gawangan tanaman karet umur 1 tahun (TBM 1) dan umur 3 tahun (TBM 3). Hasil penelitian menunjukkan bahwa pengaruh jarak ta n a m a n tu m p a n g s a r i p a d a s e tia p perlakuan tidak berbeda nyata terhadap pertumbuhan tanaman karet. Tanaman