Identification of a Disease on Cocoa Caused by Fusariumin Sulawesi

A disease presumed to be caused by Fusarium was observed in cocoa open fields with few or without shade trees. Within the population of cocoa trees in the field, some trees had died, some had yellowing leaves and dieback, and the others were apparently healthy. In order to demonstrate Fusarium species as the causal pathogen and to obtain information concerning the incidence of the disease, its distribution and its impact on sustainability of cocoa, isolation of the pathogen, inoculation of cocoa seedlings with isolates and a survey of disease has been conducted. Fusarium was isolated from roots and branches, and inoculated onto cocoa seedlings (one month old) via soil. Symptoms appeared within 3-4 weeks after infection. These symptoms consisted of yellowing of leaves beginning from the bottom until the leaves falldown, and browning internal of vascular tissue. Darkened vascular traces in the petiole characteristic of vascularstreak dieback infection were absent. The occurrence of Fusarium in the field was characterized by the absence of obvious signs of fungal infestation on root of infected trees, yellowing of leaves on twigs, dieback, and tree mortality in severe infestations. Disease incidence could reach 77% and in this situation it was difficult for trees recover from heavy infections or to be regenerated in the farm. The study proves that Fusarium is a pathogen causing dieback and the disease is called as Fusarium vascular dieback (FVD). Its development is apparently enhanced by dry conditions in the field

Plant residue based-composts applied in combination with Trichoderma asperellum improve cacao seedling growth in soil derived from nickel mine area

Cacao is widely grown in Sulawesi close to areas of nickel (Ni) mines indicating a possibility that the plant is affected by this heavy metal. By using soil collected from a Ni mining area, we evaluated three compositions of composted plant residues consisting of firstly gliricidia, billy goat, and rice straw, secondly gliricidia, stalk of palm oil fruit, and rice straw, and thirdly gliricidia, coconut husk, and rice straw, without and with addition of Trichoderma asperellum, in supporting growth of cacao seedling. Treatment with the respective compost types without any addition of T. asperellum caused an increase of seedling height by 18.9%, 28.5%, and 43.8%, stomata opening area by 17.2%, 4.3%, and 41.3%, stomata number by 13.4%, 22.7%, and 14.3%, and leaf Ni content by 3.8%, 12.8%, and 48.8% respectively. Following treatment with the three compost types included T. Asperellum, the increase of seedling height was 36.5%, 45.3%, and 54.7%, stomata opening area 15.9%, 21.3%, and 53.5%, stomata number 5.4%, 7.1%, and 0.0% and leaf Ni content 25.1%, 87.8%, and 161,4% respectively. Leaf analysis indicated that nitrogen content was increased when treated by the combination of composted plant residues and T. asperellum, potassium was increased in all treatments without T. asperellum, while phosphorus was decreased in all treated seedlings. These data suggest that one cause of cacao seedling growth improvement in soil containing Ni by composted plant residues and its combination with T. asperellum was the increase of Ni levels in leaves. Composts treatment could therefore potentially be used for cacao field application around Ni mining areas

Extensive morphological and behavioural diversity among fourteen new and seven described species in Phytophthora Clade 10 and its evolutionary implications

During extensive surveys of global Phytophthora diversity 14 new species detected in natural ecosystems in Chile, Indonesia, USA (Louisiana), Sweden, Ukraine and Vietnam were assigned to Phytophthora major Clade 10 based on a multigene phylogeny of nine nuclear and three mitochondrial gene regions. Clade 10 now comprises three subclades. Subclades 10a and 10b contain species with nonpapillate sporangia, a range of breeding systems and a mainly soil- and waterborne lifestyle. These include the previously described P. afrocarpa, P. gallica and P. intercalaris and eight of the new species: P. ludoviciana, P. procera, P. pseudogallica, P. scandinavica, P. subarctica, P. tenuimura, P. tonkinensis and P. ukrainensis. In contrast, all species in Subclade 10c have papillate sporangia and are self-fertile (or homothallic) with an aerial lifestyle including the known P. boehmeriae, P. gondwanensis, P. kernoviae and P. morindae and the new species P. celebensis, P. chilensis, P. javanensis, P. multiglobulosa, P. pseudochilensis and P. pseudokernoviae. All new Phytophthora species differed from each other and from related species by their unique combinations of morphological characters, breeding systems, cardinal temperatures and growth rates. The biogeography and evolutionary history of Clade 10 are discussed. We propose that the three subclades originated via the early divergence of pre-Gondwanan ancestors > 175 Mya into water- and soilborne and aerially dispersed lineages and subsequently underwent multiple allopatric and sympatric radiations during their global spread

OPTIMALISASI TEKNIK PCR UNTUK DETEKSI DINI BAKTERI LAYU RALSTONIA SOLANACEARUM PADA BEBERAPA VARIETAS BENIH KENTANG

Budidaya tanaman kentang seringkali dihadapkan oleh masalah hama dan penyakit tanaman yang dapat menurunkan produksi umbi kentang secara nyata. Beberapa jenis penyakit utama yang menyerang tanaman kentang adalah layu bakteri dan virus. Berdasarkan hal tersebut penelitian ini bertujuan untuk mendapatkan metode PCR yang optimal untuk deteksi dini keberadaan bakteri Ralstonia solanacearum pada empat varietas benih kentang yang selanjutnya dapat digunakan untuk produksi benih kentang yang sehat dan bebas patogen. Penelitian ini dilaksanakan di Laboratorium Bioteknologi Pertanian, Pusat Kegiatan Penelitian (PKP) Universitas Hasanuddin Makassar. Deteksi patogen penyebab layu secara molekuler (PCR) menggunakan primer spesifik untuk R. solanacearum. Sebagai kontrol positif digunakan DNA dari kultur murni R. solanacearum dan dari tanaman kentang yang diinfeksi bakteri. Pada tahap awal dilakukan proses optimalisasi ekstraksi dengan menggunakan kit dan proses ekstraksi secara manual, serta variasi pengenceran DNA pada kontrol positif. Hasil optimalisasi selanjutnya digunakan untuk mendeteksi keberadaan penyakit layu bakteri oleh R. solanacearum pada umbi benih kentang varietas Atlantik, Granola, Kalosi dan Nikola. Hasil pengujian menunjukkan bahwa ekstraksi DNA tanpa menggunakan kit memberikan hasil yang lebih baik baik dari segi kuantitats maupun kualitas. Pengujian pada empat varietas bibit kentang menunjukkan hasil yang negatif. Keberadaan R. solanacearum hanya dideteksi pada kontrol tanaman yang bergejala dan pada DNA dari kultur murni baketri yang ditandai dengan munculnya pita pada ukuran 287 bp

OPTIMALISASI TEKNIK PCR UNTUK DETEKSI DINI BAKTERI LAYU RALSTONIA SOLANACEARUM PADA BEBERAPA VARIETAS BENIH KENTANG

Budidaya tanaman kentang seringkali dihadapkan oleh masalah hama dan penyakit tanaman yang dapat menurunkan produksi umbi kentang secara nyata. Beberapa jenis penyakit utama yang menyerang tanaman kentang adalah layu bakteri dan virus. Berdasarkan hal tersebut penelitian ini bertujuan untuk mendapatkan metode PCR yang optimal untuk deteksi dini keberadaan bakteri Ralstonia solanacearum pada empat varietas benih kentang yang selanjutnya dapat digunakan untuk produksi benih kentang yang sehat dan bebas patogen. Penelitian ini dilaksanakan di Laboratorium Bioteknologi Pertanian, Pusat Kegiatan Penelitian (PKP) Universitas Hasanuddin Makassar. Deteksi patogen penyebab layu secara molekuler (PCR) menggunakan primer spesifik untuk R. solanacearum. Sebagai kontrol positif digunakan DNA dari kultur murni R. solanacearum dan dari tanaman kentang yang diinfeksi bakteri. Pada tahap awal dilakukan proses optimalisasi ekstraksi dengan menggunakan kit dan proses ekstraksi secara manual, serta variasi pengenceran DNA pada kontrol positif. Hasil optimalisasi selanjutnya digunakan untuk mendeteksi keberadaan penyakit layu bakteri oleh R. solanacearum pada umbi benih kentang varietas Atlantik, Granola, Kalosi dan Nikola. Hasil pengujian menunjukkan bahwa ekstraksi DNA tanpa menggunakan kit memberikan hasil yang lebih baik baik dari segi kuantitats maupun kualitas. Pengujian pada empat varietas bibit kentang menunjukkan hasil yang negatif. Keberadaan R. solanacearum hanya dideteksi pada kontrol tanaman yang bergejala dan pada DNA dari kultur murni baketri yang ditandai dengan munculnya pita pada ukuran 287 bp

Kebahasaan : fonologi, morfologi, dan semantik

Buku ini merupakan bahan belajar mengenai kebahasaan.vii, 318 hlm.: ilus.; 24 cm

Kebahasaan : fonologi, morfologi, dan semantik

315 hlm., 27 hlm

Oviposition deterrent and ovicidal properties of Calotropis gigantea (L.) leaf extract to Paraeucosmetus pallicornis (Dallas) in rice

Paraeucosmetus pallicornis (Dallas) is a new pest in Indonesia which decreases rice production and quality. This pest causes the grains to become flat, hollow, brownish, break easily when milled, and bitter. This research represents the first study on Calotropis gigantea extract as an oviposition deterrent and ovicide against P. pallicornis. The study was conducted under laboratory conditions using four extract concentrations i.e. 0.5, 1.0, 1.5 and 2.0%. The oviposition deterrent effect was determined by counting the number of eggs laid and hatched. Percent reproductive control (PRC) and ovicidal activity was calculated using Tennyson’s formula. Results indicated that all concentrations of C. gigantea leaf extract reduced the number of eggs laid and hatched. The PRC also showed a gradual reduction of oviposition of the P. pallicornis and the ovicidal activity ranged between 86.5 and 100%. The extract concentration which showed the highest potential as an oviposition deterrent and ovicide against P. pallicornis was in the range of 1.0–2.0%. The overall results indicated that C. gigantea leaf extract has the potential to be used as an oviposition deterrent and ovicide against P. pallicornis