17 research outputs found
Determinisme genetique de la resistance au puceron vert (Myzus persicae) chez le pecher. Resultats complementaires
Chez le pĂȘcher, une Ă©tude gĂ©nĂ©tique du mode dâhĂ©rĂ©ditĂ© de la rĂ©sistance Ă Myzus persicae a Ă©tĂ© faite Ă partir dâun gĂ©niteur rĂ©sistant S2678:47, et dâun gĂ©niteur sensible S1161:12. Cette rĂ©sistance a un dĂ©terminisme gĂ©nĂ©tique simple: elle est dominante et monogĂ©nique (symboles, Rm1, rm1). Il nây a pas de liaison entre le locus qui dĂ©termine la rĂ©sistance et les loci qui concernent le port pleureur (PI, pl), le triangle liĂ©geux (T, t), le type de fleur (Sh, sh) et la couleur de la chair du fruit (Y, y). La rĂ©sistance sâest maintenue sur 4 gĂ©nĂ©rations consĂ©cutives et nâa pas jusquâici Ă©tĂ© surmontĂ©e. Cette Ă©tude fait partie dâun programme de crĂ©ation de variĂ©tĂ©s rĂ©sistantes Ă Myzus persicae.The mode of heredity of resistance to Myzus persicae was established in the peach using a resistant parent S2678:47 and a susceptible parent S1161:12. This resistance follows a simple genetic determinism: it is dominant and monogenic (Symbols Rm1, rm1). No link was found between the locus determining aphid resistance and the loci determining weeping shape (PI, pl), corky triangle (T, t), flower shape (Sh, sh), and fruit flesh colour (Y, y). Aphid resistance was maintained over 4 consecutive generations and has not been overcome yet. This study is part of a breeding programme to create varieties resistant to Myzus persicae
Transmission experimentale du virus de la sharka par Brachycaudus persicae Passerini
Des expĂ©riences rĂ©alisĂ©es en laboratoire ont Ă©tabli que B persicae est un vecteur de la sharka. Les adultes, aptĂšres ou ailĂ©s, ont transmis le virus Ă de jeunes plants de 2 cultivars de pĂȘcher, GF 305 et Rubira. B persicae pourrait intervenir dans la propagation naturelle de la maladie car il colonise toute lâannĂ©e les vergers de pĂȘcher, abricotier et prunier.In laboratory experiments B persicae, apterous and alate adults transmitted plum pox virus to seedlings of 2 peach cultivars, GF 305 and Rubira. It is considered that the aphid might participate in the natural spread of plum pox disease because it colonizes peach, apricot and plum orchards throughout the year
Influence in vitro des composes phenoliques des jeunes feuilles du pecher, Prunus persica (L.) Batsch, sur le puceron vert du pecher, Myzus persicae Sulzer
Lâinfluence dâextraits phĂ©noliques de jeunes feuilles de pĂȘcher sur la survie et le gain pondĂ©ral des larves de Mysus persicae a Ă©tĂ© Ă©valuĂ©e en les incorporant Ă une nourriture artificielle. Les feuilles ont Ă©tĂ© prĂ©levĂ©es sur 2 hybrides issus dâun mĂȘme croisement, lâun sensible, lâautre rĂ©sistant au puceron. Les fondatrices et les fondatrigĂšnes du puceron ne demeurent pas plus de 24 Ă 72 heures sur les feuilles de lâhybride rĂ©sistant. Les extraits phĂ©noliques totaux des 2 hybrides sont dĂ©favorables au puceron mais celui provenant de lâhybride rĂ©sistant est plus dĂ©favorable car au 7e jour dâĂ©levage il est lĂ©tal Ă 300 mg 1-1 contre 600 mg 1-1. Lâhybride sensible est plus riche en phĂ©nols que lâhybride rĂ©sistant. Les fractions obtenues Ă partir des extraits totaux sont moins actives que ces derniers mais une fraction de lâhybride rĂ©sistant est trĂšs active. DiffĂ©rentes substances phĂ©noliques, ou les produits de leur transformation, sont donc dĂ©favorables Ă lâinsecte. Les 2 hybrides diffĂšrent par leur contenu en acides hydroxycinnamiques, notamment les dĂ©rivĂ©s inconnus des acides p. coumarique et fĂ©rulique. Ces substances pourraient ĂȘtre associĂ©es Ă la rĂ©sistance du pĂȘcher au puceron vert du pĂȘcher.Myzus persicae larvae were tested on synthetic diets with phenolic extracts of young peach leaves. Survival and weight increase of the nymphs were noted. Leaves were collected from 2 F2 hybrids, one susceptible and the other resistant to M. persicae. The fundatrix and the fundatrigeniae of the aphid stayed no longer than 24 to 72 h on the leaves of the resistant hybrid. Total phenolic extracts from both hybrids were deleterious to the aphid but the resistant hybrid extract was more deleterious than the susceptible one : on the 7th day, the lethal concentrations were 300 mg 1-1 and 600 mg 1-1 respectively. Fractions obtained from the whole extracts were less deleterious than the whole extracts but one fraction of the resistant hybrid extract was very deleterious. Consequently some phenolic compounds or their derivatives in the resistant hybrid seem to be more important than the higher overall level of phenolics in the susceptible hybrid. The 2 hybrids differ in their content of hydroxycinnamic acids and unknown derivatives ofp-coumaric and ferulic acids. These substances could be associated with the resistance of peach to M. persicae
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