356,323 research outputs found
International Journal of Speleology
No full textOfficial journal of the Union International de Spéléologie, the International Journal of Speleology is an international peer-reviewed scientific journal on speleology and karst-related topics including geomorphology, hydrogeology, paleoclimate, palaeoenvironment, biology, physics etc.
ISSN 0392-6672
Printed since 1964, since 1981 owned by the Società Speleologica Italiana.
Jo De Waele is Editor-in-Chief since 2005
Dirk Rochtus maakt brandhout van Koerden-uitspraak Donald Trump
No full textInterview met Dirk Rochtus over de Koerden-uitspraak van Donald Trumpstatus: Published onlin
Engineering Geology, 99(3-4) (special issue "Engineering and Environmental Problems in Karst")
No full textParise M., De Waele J., Gutierrez F., Guest-editors of the Special Issue "Engineering and environmental problems in karst, Natural and Anthropogenic Hazards in Karst Areas", 162 page
QTL mapping for resistance to and tolerance for the rice root-knot nematode, Meloidogyne graminicola
No full textAbstract Background The root-knot nematode Meloidogyne graminicola is an obligate biotrophic pathogen considered to be the most damaging nematode species that causes significant yield losses to upland and rainfed lowland rice production in South and Southeast Asia. Mapping and identification of quantitative trait loci (QTL) for resistance to and tolerance for M. graminicola may offer a safe and economic management option to farmers. In this study, resistance to and tolerance for M. graminicola in Asian rice (Oryza sativa L.) were studied in a mapping population consisting of 300 recombinant inbred lines (RILs) derived from IR78877–208-B-1-2, an aerobic rice genotype with improved resistance to and tolerance for M. graminicola, and IR64, a popular, high-yielding rice mega-variety susceptible to M. graminicola. RILs were phenotyped for resistance and tolerance in the dry seasons of 2012 and 2013. QTL analysis was performed using 131 single nucleotide polymorphism (SNP) and 33 simple sequence repeat (SSR) markers. Results Three QTLs with main effects on chromosomes 4 (qMGR 4.1 ), 7 (qMGR 7.1 ) and 9 (qMGR 9.1 ) and two epistatic interactions (qMGR 3.1 / qMGR 11.1 and qMGR 4.2 / qMGR 8.1) associated with nematode reproduction that were consistent in the two seasons were detected. A QTL affecting root galling was found on chromosomes 4 (qGR 4.1 ) and 8 (qGR 8.1 ), and QTLs for nematode tolerance were found on chromosomes 5 (qYR 5.1 ) and 11 (qYR 11.1 ). These QTLs were consistent in both seasons. A QTL for grain yield was found on chromosome 10 (qGYLD 10.1 ), a QTL affecting filled grains per panicle was detected on chromosome 11 (qFG 11.1 ) and a QTL for fresh root weight was found on chromosomes 2 (qFRWt 2.1 ), 8 (qFRWt 8.1 ) and 12 (qFRWt 12.1 ) in both seasons. The donor of the alleles for qMGR 4.1 , qMGR 7.1 , qMGR 9.1 , qGR 4.1 , qGR 8.1 , qYR 5.1 and qFRWt 2.1 was IR78877–208-B-1-2, whereas for qYR 11.1 , qGYLD 10.1 and qFG 11.1 , qFRWt 8.1 and qFRWt 12.1 was IR64. Lines having favorable alleles for resistance, tolerance and yield provided better yield under nematode-infested conditions and could be a starting point of marker-assisted breeding (MAB) for the improvement of M. graminicola resistance and tolerance in Asian rice. Conclusion This study identified a total of 12 QTLs with main effects and two epistatic interactions in the 1st season and 2nd season related to M. graminicola resistance and tolerance, and other agronomic traits such as plant yield, percentage of filled grains, and fresh and dry root weight. Rice genotypes that have the favorable alleles for resistance (qMGR 4.1 , qMGR 7.1 , qMGR 9.1 , qGR 4.1 , qGR 8.1 ) and tolerance (qYR 5.1 , and qYR 11.1 ,) QTLs, and which are either resistant or partially resistant and tolerant, were also selected. These selected genotypes and the identified QTLs are vital information in designing MAB for the improvement of high-yielding rice genotypes but are susceptible to M. graminicola infection
Geomorphology, 106(1-2) (Special Issue "Recent developments in Surface and Subsurface Karst Geomorphology” May 2009)
No full textDe Waele J., Audra Ph., Plan L., guest-editors of the Special Issue "Recent developments in Surface and Subsurface Karst Geomorphology”, (164 pages, 14 papers
Environmental Geology, 58(2), Special Issue “Current perspectives on the environmental impacts and hazards in Karst”
No full textParise M., De Waele J., Gutierrez F., guest-editors of the Special Issue “Current perspectives on the environmental impacts and hazards in Karst”, pages 235-406 (171 pages, 15 articles
Sensitivity of <i>Meloidogyne incognita</i> second-stage juvenile hatch, motility and viability to pure cucurbitacins and cucurbitacin-containing phytonematicides
No full textPrevious claims suggested that pure active ingredients from botanicals were less effective in pest management than their fermented crude-extracts. The objective of this study was to compare the toxicity of pure (98%) cucurbitacin A and B on nematode bioactivities with those of their fermented crude-extracts, the Nemarioc-AL and Nemafric-BL phytonematicides, respectively. Purified active ingredients were each diluted to 0.00, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00, 2.25 and 2.50 μg ml‒1 and their fermented crude-extracts to 0.0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0% phytonematicide. The exposure time for second-stage juveniles (J2) hatch, motility and viability of the J2 to each concentration was 24, 48 and 72 h. The overall sensitivities (Σk) of J2 hatch to Nemarioc-AL, cucurbitacin A, Nemafric-BL and cucurbitacin B were 1, 30, 5 and 2 units, respectively, for motility 7, 12, 2 and 12 units, respectively, and for viability 2, 4, 1 and 4 units, respectively. Generally, nematodes displayed high sensitivities to cucurbitacin-containing phytonematicides than to their respective purified active ingredients (cucurbitacins). In conclusion, the cucurbitacin-containing phytonematicides were more effective in nematode suppression than their purified active ingredient
Host response of Oryza glaberrima and O. sativa rice genotypes to the rice root-knot nematode Meloidogyne graminicola in a hydroponic system under growth chamber
No full text© 2016 Taylor & Francis. The host response of 25 rice genotypes belonging to Oryza glaberrima and Oryza sativa to Meloidogyne graminicola infection was examined in a hydroponic system. The M. graminicola can build up high population densities in a hydroponic system. Resistance to this nematode species was found in O. glaberrima genotypes which supported significantly lower nematode numbers per plant and per unit root than O. sativa genotypes. The M. graminicola-infected O. sativa genotypes showed a higher root galling index than the O. glaberrima genotypes. The hydroponic system is efficient and reliable method to examine the host response of rice genotypes to M. graminicola infection, and can be useful for the fast screening of high numbers of rice genotypes for the selection of M. graminicola-resistant rice germplasm for breeding purposes.status: Publishe
Arbuscular Mycorrhizal Fungi for the Biocontrol of Plant-Parasitic Nematodes: A Review of the Mechanisms Involved
No full textArbuscular mycorrhizal fungi (AMF) are obligate root symbionts that can protect their host plant against biotic stress factors such as plant-parasitic nematode (PPN) infection. PPN consist of a wide range of species with different life styles that can cause major damage in many important crops worldwide. Various mechanisms have been proposed to play a role in the biocontrol effect of AMF against PPN. This review presents an overview of the different mechanisms that have been proposed, and discusses into more detail the plausibility of their involvement in the biocontrol against PPN specifically. The proposed mechanisms include enhanced plant tolerance, direct competition for nutrients and space, induced systemic resistance (ISR) and altered rhizosphere interactions. Recent studies have emphasized the importance of ISR in biocontrol and are increasingly placing rhizosphere effects on the foreground as well, both of which will be the focal point of this review. Though AMF are not yet widely used in conventional agriculture, recent data help to develop a better insight into the modes of action, which will eventually lead toward future field applications of AMF against PPN. The scientific community has entered an exciting era that provides the tools to actually unravel the underlying molecular mechanisms, making this a timely opportunity for a review of our current knowledge and the challenges ahead.sponsorship: This work was financially supported by a specialization grant from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen) to NS and an EU Marie-Curie International Outgoing Fellowship (PIOF-GA-2013-625551) to CV. NS is the main author. DDW corrected the first drafts of the manuscript and commented on the views and statements put forward with emphasis on the nematological content of the manuscript. BP was responsible for the daily supervision of the PhD work of NS, corrected the drafts of the manuscript and commented on its content. CV designed the review outline, co-wrote the manuscript and designed the figures. (Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen), EU Marie-Curie International Outgoing Fellowship|PIOF-GA-2013-625551)status: Publishe
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