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Manis Subang, Indonesia

Koide Y.,International Rice Research Institute | Koide Y.,Japan International Research Center for Agricultural science | Kawasaki A.,Japan International Research Center for Agricultural science | Telebanco-Yanoria M.J.,International Rice Research Institute | And 7 more authors.
Plant Breeding

Gene pyramiding is considered one of the most effective strategies for achieving durable resistance against blast disease (Magnaporthe oryzae B. Couch) in rice (Oryza sativa L.), although few studies have evaluated the combining effect of the resistance genes. We report the development of pyramided lines with two major blast resistance genes, Pish and Pib, and the evaluation of the combining effect of them. The two genes pyramided lines were selected from the progenies of a cross between one near isogenic line (NIL), which harbours Pish, and another NIL, which harbours Pib, in the genetic background of blast susceptible variety, CO 39. The presence of the resistance genes was confirmed by DNA markers linked to them. To obtain DNA markers for Pish, we genetically mapped the Pish locus. We confirmed the additive effect of Pish and Pib in the pyramided lines by their reaction patterns to blast isolates, suggesting the potential availabilities of the combinations of these genes. In addition, we provide DNA markers linked to Pish for marker aided selection in rice blast resistance breeding. © 2010 Blackwell Verlag GmbH. Source

Horgan F.G.,International Rice Research Institute | Naik B.S.,Directorate of Rice Research | Iswanto E.H.,Indonesian Center for Rice Research | Almazan M.L.P.,International Rice Research Institute | And 2 more authors.
Entomologia Experimentalis et Applicata

This study examines the nature of intraspecific interactions among Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) planthoppers feeding on resistant and susceptible rice varieties. Planthopper nymphs produced less honeydew and gained less weight when feeding on rice variety IR62 (resistant) compared to susceptible rice varieties. A series of bioassays was conducted that varied N. lugens nymph densities on IR62 and IR22 (susceptible). Increasing nymph density facilitated feeding by conspecifics; however, intraspecific competition increased mortality of nymphs on IR62 (but rarely on IR22). Furthermore, nymph weights declined with increasing conspecific density on IR22, and the effects were weak on IR62. More female nymphs than males survived on IR62 but this was not affected by density. Nitrogenous fertilizer increased competition among N. lugens on young plants of IR22, but not on IR62. Results indicate that nymphs have a low efficiency in accessing resources when feeding on IR62, even where the plants have received fertilizer. Female-biased survival and biomass compensation for mortality may promote population recovery after development on the resistant plant and accelerate adaptation to the resistant variety. Entomologia Experimentalis et Applicata © 2016 The Netherlands Entomological Society. Source

Safitri H.,Indonesian Center for Rice Research | Purwoko B.S.,Bogor Agricultural University | Dewi I.S.,Indonesian Center for Agricultural Biotechnology | Ardie S.W.,Bogor Agricultural University
Journal of the International Society for Southeast Asian Agricultural Sciences

Salt accumulation in irrigated soil is one of the main factors limiting rice productivity. A greenhouse experiment was conducted at Cimanggu Experiment Station, Bogor, Indonesia from May to September 2014 using a completely randomized design in a factorial arrangement with three replications. Four salt tolerant and two salt sensitive genotypes of rice were used in this experiment. The treatments were five concentrations of NaCl (0, 20, 40, 60 and 80 mM) applied on 21 day-old seedlings and maintained until harvest time. The study sought to evaluate the response of several rice genotypes to various NaCl concentrations through observation of morphological and physiological characters. The study showed that the increase of NaCl concentrations in soil significantly reduced plant height, number of panicles plant-1, panicle length, leaf length, 1000 grain weight, and grain yield. On physiological characters, salinity increased [Na+], decreased [K+] and [Ca2+] concentrations, and reduced K+/Na+ and Ca2+/Na+ ratios in the leaf tissue. The addition of 40 mM NaCl can distinguish tolerant and sensitive genotypes. The grain yield of sensitive genotypes decreased 90-100% at 40 mM NaCl, while the tolerant genotypes showed <70% in grain yield reduction. © 2016, International Society for Southeast Asian Agricultural Sciences. All Rights Reserved. Source

Blyton M.D.J.,Australian National University | Herawati N.'A.,Australian National University | Herawati N.'A.,Indonesian Center for Rice Research | O'Brien C.L.,The Canberra Hospital | And 2 more authors.
Environmental Microbiology Reports

The probability of detecting Escherichia coli varies between host species with different diets and body sizes. An experimental study that mimicked the effect of different carnivore body masses found that digesta transit times influence E.coli abundance. In this study, we investigated how the host's gastrointestinal dynamics affected E.coli abundance and genotype in a system that reflected an herbivorous host. Forty rats from nine litters were fed a diet high in fermentable fibre. We found a small effect of fibre concentration on the difference between the liquid and particle digesta retention times. However, the rats' litter membership explained the majority of the retention time differences (79%). In turn, we found that as the difference between liquid and particle retention times increased, E.coli faecal cell densities decreased, while the likelihood that an animal's dominant E.coli strain possessed a gene involved in adhesion (agn43) increased. Thus, this experiment revealed an unanticipated high degree of association between the hosts' litter, their gastrointestinal dynamics and the E.coli genotypes. Furthermore, by comparing our findings to previous work, we show that the presence of fermentable fibre in the diet appears to change the relationship between the host's phenotype and E.coli. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd. Source

Suwarto,Jenderal Soedirman University | Susanto U.,Indonesian Center for Rice Research | Nurchasanah S.,Jenderal Soedirman University
Research Journal of Pharmaceutical, Biological and Chemical Sciences

Using the variability present in the F2 population originating from New Plant Type (NPT) rice population, selection was practiced for high grain yield. Expected response to selection was estimated in F3 generation and compared with F2 generation. The F3 generation showed significant positive selection response for plant height, number of grain per panicle, panicles length, and flowering (days to 50% flowering), thus indicating the effectiveness of selection for these characters. This indicates the effectiveness of selection for these characters in F2 generation. The correlation and regression coefficient between F2 and F3 generation was significant for these characters. But, grain yield per clump showed non significant response in F3 generation. The correlation and regression coefficient between F2 and F3 generation was non significant for grain yield per clump, which indicates straight selection for this character during early generation (F2) may not be effective. Selection for plant height, number of grain per panicle, panicles length, and flowering (days to 50% flowering) can be made in the early segregating generation. Grain yield per clump is not effective for selection in early generation. Source

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