Communautés de nématodes phytoparasites dans la Réserve de Biosphère de l arganeraie marocaine : réponse à l anthropisation

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1 Communautés de nématodes phytoparasites dans la Réserve de Biosphère de l arganeraie marocaine : réponse à l anthropisation Plant-parasitic nematode communities in the Moroccan Argan Biosphere reserve: responses to anthropization A. El Mousadik Z. Ferji T. Mateille B. Martiny J. Tavoillot

2 Background 1 : the plant-parasitic nematodes plant-parasitic nematodes (PPN) are obligate parasites living in soil and plantroots. IRD PPN are everywhere present in communities (= mixtures of species). they do not migrate long distances (=> no natural invasions). plant production depend more on community structures than on emblematic species.

3 Background 2 : ecology of communities PPN management requires prior knowledge about species coexistence in communities. evolution approach + Comparative approach between ecosystems natural or relict ecosystems & synchronic analyses Original system (Argan forest) land-use changes Anthropized system (crops)

4 Background 3 : major cropping systems in Argan Biosphere root-knot nematodes Associated crops grain crops vegetables Total deforestation vegetables under greenhouses citrus orchards lesion nematodes cropping intensification => increased parasitic constraints e.g. PPN that induce high yield losses.

5 Questionning: 1. Are these nematodes present in the natural Argan forest? 2. How PPN communities respond to land-use changes? 3. What factors are involved in structuring the communities? Risks? - for agroforestry strategies. - for Argan forest regeneration and intensification.

6 Materials & Methods Chichaoua river C h i a d m a Essaouira 1 2 Tensift river Chichaoua El Mehl river Marrakech 27 sites x 3 trees (100m transects) = 81 samples + geolocalisation + modality (natural / cropped) + plant communities Zeltene river Nfiss river Sidi-Ifni Guelmin 20 D r a a Agadir 15 Tiznit Bouzakaren 27 H a h a Asif Tinkert Argana Taroudant Tafraout H i g h - A t l a s S o u s s - M a s s a Massa river A n t i - A t l a s Noun river Msanda et al., Souss river Igherm M o r o c c o Aoulouz 9 Oostenbrink soil elutriation ISO_ morphological diagnostics (genus level) Species diagnostics incognita primers incognita 1500 pb 1000 pb 800 pb 600 pb 400 pb 200 pb jav/aren/inc primers arenaria molecular approach morphology

7 Number of taxa Results 1 Very high richness = 12 families 34 genera 70 species diversity 40 C = Chiadma H = Haha HA = Haut-Atlas SM = Souss-Massa 30 AA = Anti-Atlas D = Draa y = 16.06ln(x) R 2 = 0.80 C C D D y = 9.63ln(x) R 2 = 0.84 HA H H HA Number of samples AA SM AA SM species genera Richness = f(sampling effort)

8 Results 2 Shannon-Wiener Nematodes /dm 3 ofsoil (x10 3 ) diversity Eveness index Number of species 2 Abundance (N) NS Richness (S) NS a a Diversity a Eveness Evenness (E) ab b ab b b ab b ab b b Chiadma Haha Haut-Atlas Souss Massa Anti-Atlas Draa Chiadma Haha Haut-Atlas Souss Massa Anti-Atlas Draa 0 => decrease of diversity and evenness from North to South

9 Mean abundance (Log N/dm 3 of soil) Results Cac Ned Cos Zyg Rot Nep Qui Lon Bol Amp Nag Het Mac Dit Ott Bit Mal Sau Hop Bas Tyl Apo Pra Mel Scu Not Mer Hel Xip Fil Par Pro Amp = Amplimerlinius Apo = Aphelenchoides Apu = Aphelenchus Bas = Basiria Bol = Boleodorus Bit = Bitylenchus Cac = Cactodera Cos = Coslenchus Dit = Ditylenchus Fil = Filenchus Hel = Helicotylenchus Het = Heterodera Hop = Hoplolaimus Lon = Longidorus Mac = Macroposthonia Mal = Malenchus Mel = Meloidogyne Frequency (%) Tel Apu dominant genera Mer = Merlinius Nag = Nagelus Ned = Neodolichorhynchus Nep = Neopsilenchus Not = Nothotylenchus Ott = Ottolenchus Par = Paratylenchus Pro = Pratylenchoides Pra = Pratylenchus Qui = Quinisculcius Rot = Rotylenchus Sau = Sauertylenchus Scu = Scutylenchus Tel = Telotylenchus Tyl = Tylenchorhynchus Xip = Xiphinema Zyg = Zygotylenchus Dominance

10 Mean abundance (Log N/dm 3 of soil) Results Cac Ned Cos Zyg Rot Nep Qui Lon Bol Amp Nag Het Mac Dit Ott Bit Mal Sau Hop Bas Tyl Apo Pra Mel Scu Not Mer Hel Xip Fil Amp = Amplimerlinius Apo = Aphelenchoides Apu = Aphelenchus Bas = Basiria Bol = Boleodorus Bit = Bitylenchus Cac = Cactodera Cos = Coslenchus Dit = Ditylenchus Fil = Filenchus Hel = Helicotylenchus Het = Heterodera Hop = Hoplolaimus Lon = Longidorus Mac = Macroposthonia Mal = Malenchus Mel = Meloidogyne Frequency (%) dominance PPN specialized on vegetables and on fruit crops are present and more or less abundant in the natural Argan forest. Par Pro Tel Apu Mer = Merlinius Nag = Nagelus Ned = Neodolichorhynchus Nep = Neopsilenchus Not = Nothotylenchus Ott = Ottolenchus Par = Paratylenchus Pro = Pratylenchoides Pra = Pratylenchus Qui = Quinisculcius Rot = Rotylenchus Sau = Sauertylenchus Scu = Scutylenchus Tel = Telotylenchus Tyl = Tylenchorhynchus Xip = Xiphinema Zyg = Zygotylenchus

11 Results 4 community patterns TEL F2=13.4 % G1 F1=17.4 % APH ROT HEL PR HET A PRO PAR ZYG SC MEU L HOP LON G3 G2 G1 F1 G2 MER TYL Argan haplotype groups (Gn) G3 no correspondence with with Argan climatic diversity. conditions. altitude. El Mousadik & Petit, 1996

12 Results 5 community patterns TEL F2=13.4 % F1=17.4 % APH ROT HEL MER TYL PR HET A PRO PAR ZYG SC MEU L HOP LON Cup Are Eup Cac Rha F1 Cac = Cactaceae Are = Arecaceae Eup = Euphorbiaceae Rha = Rhamnaceae Cup = Cupressaceae correspondence with Argan forest typology Opuntia ficus-indica Euphorbia echinus

13 Results 6 community patterns TE L F2=13.4 % Crop effect F1=17.4 % APH ROT HEL PR HET A PRO PAR ZYG SCU ME L HOP LON N C F1 N = natural C = cropped MER TYL N = «wild» ; C = cropped Longitude effect W1 correspondence with land-use changes and with soils W5 W2 W3 W4 F2 W5 W4 W3 W2 W

14 Conclusion In natural conditions evidence of PPN community structuration in the Argan Biosphere reserve according to its typology (genetic variation of A. spinosa, Argan landscapes). In cropped conditions undercropping leads to the development of specialized PPN species. It can be concluded that anthropic disturbances (especially cropping) induce new PPN community structures with high pathogenicity. Risk anticipation what risks induced by agroforestry intensification? what risks for new Argan orchards? resistance screenings of Argan accessions biocontrol strategies (mycorrhization)? Photo R. Bellefontaine (2010) Photo R. Bellefontaine (2010)

15 Acknowledgements Pr. I. Aïtichou Pr. A. Aït Benaomar Pr. H. Boubaker Pr. H. Boudyach Pr. H. Lakhtar Pr. F. Lekjaa Pr. C. Harrouni M. Boulabiar Dr. E. Dmowska Dr. R. Arfi Thank you for your attention