Menjivar Barahona, Roy Donald: The systemic activity of mutualistic endophytic fungi in Solanaceae and Cucurbitaceae plants on the behaviour of the phloem-feeding insects Trialeurodes vaporariorum, Aphis gossypii and Myzus persicae. - Bonn, 2010. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc:
author = {{Roy Donald Menjivar Barahona}},
title = {The systemic activity of mutualistic endophytic fungi in Solanaceae and Cucurbitaceae plants on the behaviour of the phloem-feeding insects Trialeurodes vaporariorum, Aphis gossypii and Myzus persicae},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2010,
month = jun,

note = {The biocontrol activity of mutualistic endophytic fungi inoculated into the rhizosphere on the root-knot nematode Meloidogyne incognita and the phloem-feeding insects: Trialeurodes vaporariorum (Westwood) the green house whitefly (GHWF), Aphis gossypii (Glover) the melon aphid, and Myzus persicae (Sulzer) the green peach aphid were investigated on host plants in two plant families.
Fusarium oxysporum strain 162 (Fo162) was successfully re-isolated from the roots of squash, melon and pepper, 27.8, 27.4 and 28.8 percent respectively, following endophyte pre-inoculation at sowing. The results showed for the first time that Fo162 was able to effectively colonize these three new host plants. Early root penetration of M. incognita was reduced 83, 70 and 73 percent in the three plants, respectively. In the absence of Fo162, the level of nematode galling was significantly higher in all crops compared to the rate of galling on endophyte inoculated plants. Organic matter amendments did not affect the biological control activity of Fo162. Strain Fo162 as well as five other endophytic isolates with known biological control activity toward plant-parasitic nematodes, were investigated for their potential to induce systemic effects against the GHWF on tomato. The endophytic isolates of Trichoderma atroviride MT-20 and S-2 as well as Fo162 added to the soil at sowing significantly reduced the number of GHWF on the leaves of tomato over the controls in a choice-test as measured over a 10 day period after insect release. The highest level of biocontrol activity was obtained with Fo162. The endophytic fungi did not alter chlorophyll content of the tomato leaves, which was thought to have influenced host selection behaviour. The choice-test also demonstrated that Fo162 negatively affected GHWF behaviour on tomato, squash, and melon at the time of host selection and oviposition. 79 and 74 percent of the adults and eggs detected on the tomato leaves were found on untreated plants, whereas on squash and melon plants the presence of Fo162 reduced host preference of the GHWF equally 80 percent. Significant negative effects of Fo162 on T. vaporariorum reproduction in tomato, A. gossypii in melon and squash as well as on M. persicae in pepper were also detected. Tomato plants treated with Fo162 had a reduced number of 2nd and 3rd nymphal stages and total eggs that were able to complete their life cycle. In squash there was a significant negative effect on the reproductive rate of the melon aphid and in Fo162 treated plants as compared to the control plants. Pepper plants inoculated with Fo162 also had a negative effect on the reproduction of the green peach aphid. Final populations only reached 15% on treated plants of that attained on the untreated plants. RP-HPLC analysis demonstrated that tomato, squash, melon and pepper plants colonized by Fo162 had altered concentrations of metabolite accumulation both in the presence and in the absence of the phloem-feeding insects. Metabolite accumulation in the presence of the phloem-feeding insect populations increased and was negatively correlated with different developmental stages of T. vaporariorum. The results of the present studies demonstrated that the mutualistic fungal endophytes are able to induce systematic resistance in host plants when applied to the soil at sowing. Endophytic root colonization enhanced systemically plant defence mechanisms simultaneously against the root-knot nematode M. incognita in the roots and toward phloem-feeding insects in the leaves.},

url = {}

The following license files are associated with this item: