Einfluss unterschiedlicher Inokulationstiefen mit dem arbuskulären Mykorrhizapilz Glomus mosseae auf die Mykorrhizierung bei Reben (Vitis sp.) in Wurzelbeobachtungskästen

In einem Gefäßversuch mit Grünstecklingen der Unterlagssorte SO 4 (Vitis berlandieri x Vitis riparia) wurde der Einfluss einer unterschiedlichen Bandinokulation mit dem AM-Pilz Glomus mosseae (Nicol. et Gerd.) Gerdemann et Trappe auf die Entwicklung des Pilzes innerhalb des Wurzelsystems untersucht. Hierbei wurde in 70 cm tiefe Wurzelbeobachtungskästen mit einem P-armen, sterilisierten Rebschulboden in eine Tiefe von 9-18 cm bzw. 36-45 cm eine 9 cm dicke Inokulationsschicht eingebracht. Im unmittelbaren Inokulationsbereich war bei beiden Inokulationsvarianten mit 45 bzw. 35% der AM-Infektionsgrad am höchsten. Mit zunehmendem Abstand vom Inokulationsband waren die Rebwurzeln geringer mykorrhiziert bzw. es konnte keine AM-Infektion festgestellt werden. Durch die Inokulation im oberen Bodenbereich wurden Trockengewicht und P-Gehalt der SO 4-Stecklinge erhöht. Die Zn-Gehalte in den Blattspreiten waren bei beiden Inokulationsmethoden erhöht, der Cu-Gehalt bei Inokulation des unteren Bodenbereichs. Bereits eine Teilbesiedlung des Wurzelsystems mit AM führte zu ausreichenden Inokulationserfolgen in Form von erhöhten Nährstoffgehalten in den Blättern und erhöhter Trockensubstanzbildung. Die Inokulation in der größeren Bodentiefe (36-45 cm) führte zu einer verzögerten Mykorrhizierung der Wurzeln, so dass möglicherweise die positiven Effekte des AM-Pilzes bei dieser Inokulationsmethode nicht zum Tragen kamen.Influence of different inoculum places of the mycorrhizal fungus Glomus mosseae on mycorrhizal colonization in grapevine rootstocks (Vitis sp.)Grapevine rootstocks (Vitis berlandieri x Vitis riparia, cv. SO 4) were grown in pots with sterilised soil with low P level from a nursery to test the effect of a local supply of inoculum of an arbuscular mycorrhizal fungus (Glomus mosseae [Nicol. et Gerd.] Gerdemann et Trappe) on mycorrhizal colonization of the root system. The inoculum was placed in a 9-cm deep band either in 9-18 cm or in 36-45 cm soil depths. After 6 weeks of growth, mycorrhizal colonisation of roots was highest in the inoculated soil zone. With increasing distance from the inoculum band, mycorrhizal colonization decreased or was absent. When the inoculum was placed in the top soil, the shoot dry weight and the leaf blade Zn and P concentrations significantly increased in mycorrhizal as compared to nonmycorrhizal plants. When the inoculum was placed in 36-45 cm soil depth, leaf blade Zn and Cu concentrations increased in mycorrhizal plants, but shoot dry weight was not affected. In conclusion, a locally restricted mycorrhizal colonization of the root system was sufficient to increase growth and nutrient uptake of grape rootstocks

Effects of different N fertilizers on the activity of Glomus mosseae and on grapevine nutrition and berry composition

Grapevine N fertilization may affect and be affected by arbuscular mycorrhizal (AM) fungal colonization and change berry composition. We studied the effects of different N fertilizers on AM fungal grapevine root colonization and sporulation, and on grapevine growth, nutrition, and berry composition, by conducting a 3.5-year pot study supplying grapevine plants with either urea, calcium nitrate, ammonium sulfate, or ammonium nitrate. We measured the percentage of AM fungal root colonization, AM fungal sporulation, grapevine shoot dry weight and number of leaves, nutrient composition (macro- and micronutrients), and grapevine berry soluble solids (total sugars or degrees Brix) and total acidity. Urea suppressed AM fungal root colonization and sporulation. Mycorrhizal grapevine plants had higher shoot dry weight and number of leaves than non-mycorrhizal and with a higher growth response with calcium nitrate as the N source. For the macronutrients P and K, and for the micronutrient B, leaf concentration was higher in mycorrhizal plants. Non-mycorrhizal plants had higher concentration of microelements Zn, Mn, Fe, and Cu than mycorrhizal. There were no differences in soluble solids (degrees Brix) in grapevine berries among mycorrhizal and non-mycorrhizal plants. However, non-mycorrhizal grapevine berries had higher acid content with ammonium nitrate, although they did not have better N nutrition and vegetative growth

Arbuscular mycorrhiza symbiosis in viticulture: a review

International audienceAbstractViticulture is a major worldwide economic sector with a vine area of 7.52 million ha, wine production of 288 Mhl, and wine exports of 26 billion euros. Nevertheless, viticulture has to adapt to new challenges of pest management, such as pesticide reduction, and climate change, such as increasing droughts. Viticulture adaptation can benefit from arbuscular mycorrhiza, a plant–fungus symbiosis. Here, we review the ecosystemic services of arbuscular mycorrhiza for grapevine production. The major points are the following: (1) arbuscular mycorrhiza fungi increase grapevine growth and nutrition by a better access to soil nutrients and by activating the regulation of plant transport proteins for phosphorus (P), nitrogen (N), and other elements. (2) Arbuscular mycorrhiza fungi increase the tolerance to abiotic stresses such as water stress, soil salinity, iron chlorosis, and heavy metal toxicity. (3) Arbuscular mycorrhiza fungi protect against biotic stresses such as root diseases. (4) Arbuscular mycorrhiza fungi produce glycoproteins and a dense hyphal network that increases soil stability and save soil nutrients up to 14 % of the grape production income. (5) P fertilisation reduces mycorhization. (6) Using herbaceous plants as cover crops favors arbuscular mycorrhiza fungi