Ecole Nationale Supérieure Agronomique de Montpellier ... - CIAM

More documents

Recommendations

Info

B. Bilan Ce travail a permis de disposer d’une technique pour détecter spécifiquement l’agent responsable de l’ESFY dans des plantes ou des insectes ; des protocoles de quantification du phytoplasme dans son vecteur ont également été définis. Ces méthodes peuvent ensuite être utilisées dans deux types d’études présentées dans les paragraphes suivants : un suivi exploratoire du taux d’infection du vecteur en conditions naturelles, et une série d’expériences en conditions contrôlées sur les capacités de C. pruni à acquérir et à transmettre le phytoplasme. III. Prévalence et transmissibilité de ‘Ca. P. prunorum’ dans les populations naturelles de son vecteur On souhaite connaître l’évolution des capacités d’acquisition et de transmission de C. pruni au cours de sa vie pour déterminer en particulier si chaque stade peut acquérir et transmettre le phytoplasme de l’ESFY pendant la période qu’il passe sur les Prunus. Une première approche a consisté à explorer le fonctionnement du système en conditions naturelles. La proportion d’insectes porteurs du phytoplasme a été suivie d’une part sur les lieux d’hivernage identifiés, et d’autre part au cours de la période passée par le vecteur dans un massif de prunelliers isolé contenant des plantes infectées par ‘Ca. P. prunorum’. A. Article III : “Survival of European Stone Fruit Yellows Phytoplasma Outside Fruit Crop Production Areas: a Case Study in Southeastern France” Michel Yvon, Gérard Labonne et Gaël Thébaud Acta Horticulturae (2004) 657 : 477-481 - 60 -
Survival of European Stone Fruit Yellows Phytoplasma Outside Fruit Crop Production Areas : a Case Study in Southeastern France M. Yvon, G. Labonne and G. Thébaud INRA, UMR BGPI, 2 place Viala, 34060 Montpellier, France Keywords: ESFY, epidemiology, Cacopsylla pruni, Prunus spinosa, overwintering ABSTRACT The aim of the study was to assess the role of blackthorn (Prunus spinosa) in the epidemiological cycle of ESFY and to search if an epidemiological cycle may exist independantly of stone fruit orchards. A typical blackthorn hedge was chosen in an area free of fruit orchards. A sample of 58 plants was tested for ESFY and 2 plants were detected infected. Samples of the population of Cacopsylla pruni (vector of ESFY) found on the hedge were taken at regular intervals from February to June and were tested for the presence of ESFY. The proportion of reimmigrants (C. pruni arriving after overwintering to reproduce on Prunus) infected remained stable during their 3 months of presence. Infected individuals were also detected in the new generation. On overwintering sites (conifers in a montainous area several km apart on the North-West), 2 C. pruni were detected infected by ESFY. From these results it is suggested that an epidemiological cycle of ESFY can be achieved in wild reservoirs of the phytoplasma even in the absence of Prunus orchards. On the other hand, the blackthorn hedge do not seem to be a very efficient reservoir of ESFY. INTRODUCTION European stone fruit yellows phytoplasma (ESFY-P) damages mainly apricot (Prunus armeniaca) and Japanese plum (P. salicina) crops, but can also be hosted by other Prunus species, either cultivated (P. amygdalus, P. domestica), used as rootstock (P. cerasifera, P. marianna) or wild (P. spinosa). In the south of France, the desease on apricot trees (apricot chlorotic leaf roll) has been noticed many years ago (Chabrolin, 1924) and is considered to be the first cause of decline of this crop in some areas (Lemaire et al., 1998). During the last years, large apricot and Japanese plum orchards were planted over previously uncultivated areas. In some cases a high prevalence of ESFY has been observed in the new orchards. Thus the question of the arrival of the first inoculum in these new areas arised. The first inoculum can originate from planting material, from infectious vectors comming from abroad or from wild reservoirs of phytoplasma which act as sources for the vectors. Each of these 3 origins is possible : althought a strict certification scheme is used for Prunus trees, infected plants are sometimes noticed in nurseries ; wild spontaneous or subspontaneous Prunus reservoirs of ESFY phytoplasma were demonstrated (Carraro et al., 2002, Jarausch et al , 2001) ; the vector has been identified as the psyllid Cacopsylla pruni (Carraro et al., 1998). It is suspected to migrate between Prunus and conifers (Ossiannilsson, 1992 ; Lauterer, 1999) and to be infectious at the time it arrives on its Prunus host-plants (reimmigrants) to reproduce (Carraro et al., 2001). In this work, we search if an epidemiological cycle may exist independantly of stone fruit orchards and can constitute a threat for new plantations. We investigated the infection status of the psyllid population from a typical P. spinosa hedge far from any area of infected Prunus orchards and then the status of infection of 2 populations at their overwintering sites. MATERIAL AND METHODS Location of the Blackthorn Plants The study was carried out in the Languedoc plain, in an area of « garrigue» vegetation and vineyards. The first stone fruit orchards were 25 to 30 km apart and they are grown under - 61 -
Page 1 and 2:
Ecole Nationale Supérieure Agronom
Page 3 and 4:
Glossaire A leur première occurren
Page 5 and 6:
C. Conclusions sur l’étude des v
Page 7 and 8:
Introduction - 7 - « Deux grands m
Page 9 and 10: l’intensification permanente de l
Page 11 and 12: Ceci nous amène aux enjeux liés
Page 13 and 14: (b) Coût de la lutte contre l’ES
Page 15 and 16: Royaume- Uni Espagne Allemagne Belg
Page 17 and 18: 1992) ; par contre, le cerisier dou
Page 19 and 20: 6) Vection Le vecteur de l’ESFY (
Page 21 and 22: (b) Caractéristiques de la vection
Page 23 and 24: Conifères ? Rétention du phytopla
Page 25 and 26: Partie I : Identifier des facteurs
Page 27 and 28: Identifying Risk Factors from a Sur
Page 29 and 30: MATERIALS AND METHODS Data Record a
Page 31 and 32: visual inspection of their spatial
Page 33 and 34: Influence of the Risk Factors. The
Page 35 and 36: Model Application This kind of mode
Page 37 and 38: ACKNOWLEDGEMENTS We are much indebt
Page 39 and 40: 42. Seemüller, E., and Schneider,
Page 41 and 42: TABLE 5: Analysis of deviance for e
Page 43 and 44: Fig. 2. Examination of the model fi
Page 45 and 46: II. Bilan Au-delà des effets évid
Page 47 and 48: Partie II : Identifier les cycles b
Page 49 and 50: A toolbox for the specific detectio
Page 51 and 52: Bordeaux). Plant samples were also
Page 53 and 54: cycles). The analyses were performe
Page 55 and 56: The above semi-quantification relie
Page 57 and 58: Table 1. Sequence of the primers an
Page 59: ESFY G1R (X) ESFY G2 (X) AP15R (X)
Page 63 and 64: C. pruni Reimmigrants The percentag
Page 65 and 66: Table 1. Detection of ESFY from C.
Page 67 and 68: Si l’expérience est répétée d
Page 69 and 70: Il y a cependant deux réserves à
Page 71 and 72: The spread of European stone fruit
Page 73 and 74: inside the cage. The cages were rem
Page 75 and 76: Quantification of ‘Ca. P. prunoru
Page 77 and 78: prunorum’: the infectious reimmig
Page 79 and 80: Table 2. Occurrence of Cacopsylla p
Page 81 and 82: Number of C. pruni on P. spinos 40
Page 83 and 84: V. Bilan sur le fonctionnement de l
Page 85 and 86: Partie III : Tester des hypothèses
Page 87 and 88: émergents migrent dans des massifs
Page 89 and 90: identique à Qc(d) sauf qu’elle e
Page 91 and 92: MATERIALS AND METHODS Characteristi
Page 93 and 94: allows summarising in one graph (i)
Page 95 and 96: (A) (B) Fig. 1. Summary of the spat
Page 97 and 98: Investigating Disease Spread betwee
Page 99 and 100: when some plants may be missing for
Page 101 and 102: the graphical display by an appropr
Page 103 and 104: shows that the proportion of missin
Page 105 and 106: the approach developed by Pélissie
Page 107 and 108: APPENDIX Test 2. This section corre
Page 109 and 110: several types of points. J. R. Stat
Page 111 and 112:
TABLE 4. Type I error and power of
Page 113 and 114:
Fig. 2. Spatiotemporal pattern of d
Page 115 and 116:
IV. Application à l’analyse de c
Page 117 and 118:
Verger D1-4 Verger BH1 Verger BH2 V
Page 119 and 120:
annuelle (Figure 1 de l’Article V
Page 121 and 122:
consiste à disposer de vergers à
Page 123 and 124:
Partie IV : Synthétiser l’inform
Page 125 and 126:
Tableau 6. Propriétés biologiques
Page 127 and 128:
Conclusion - 127 - « Il importe de
Page 129 and 130:
fonctionnement du système épidém
Page 131 and 132:
Tableau 7. Avantages et inconvénie
Page 133 and 134:
malades correspondrait alors unique
Page 135 and 136:
Expérimentations expérimentales S
Page 137 and 138:
Références bibliographiques - 137
Page 139 and 140:
30. Chabrolin C. (1924) Quelques ma
Page 141 and 142:
86. Institute of Medicine (1992) Em
Page 143 and 144:
138. Morvan G. (1977) Apricot chlor
Page 145 and 146:
190. Torres E., Martin M. P., Paltr
Page 147 and 148:
Annexes - 147 -
Page 149 and 150:
if (estim!=1) W2.99) text(B2,0,past
Page 151 and 152:
if ((sum(Do[1:4])!=0)&(sum(do1D)==0
Page 153 and 154:
III. Annexe 3 : Programme R pour si
Page 155 and 156:
IV. Annexe 4 : “Testing Boolean A
Page 157 and 158:
Testing boolean assumption in the n
Page 159 and 160:
ehavior, which is difficult to obse
Page 161 and 162:
distributed. So, the length distrib
Page 163 and 164:
ule which transforms the tangent po
Page 165 and 166:
large void segments will clearly ap
Page 167 and 168:
together with local measurements at
Page 169 and 170:
Kamphorst E.C. , Chadøeuf J. , Jet
Page 171 and 172:
c.d.f 0.0 0.2 0.4 0.6 0.8 1.0 0 1 2
Page 173 and 174:
0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4
Page 175 and 176:
c.d.f. c.d.f. c.d.f. 0.0 0.2 0.4 0.
Page 177:
RESUME Les maladies (ré-)émergent
show all

Ecole Nationale Supérieure Agronomique de Montpellier ... - CIAM

Create successful ePaper yourself

Delete template?

Save as template?