Abstract
Sustainable agriculture aims to manage soil and plant health while relying less on chemical inputs. The
individual effect of organic amendments or resistant crop cultivars on the suppression of root pests
through modulating soil and plant performance is being well documented. However, the interactions
between organic amendments and crop cultivars are less well studied. A pot experiment was conducted
across two tomato cultivars of distinct resistance to root-knot nematodes (RKNs, Meloidogyne incognita)
with three amendments including inorganic fertilizer (IF), conventional compost (CC) and vermicompost
(VC). All treatments were inoculated with second-stage juveniles of M. incognita to simulate the root-
knot nematode disease in
field condition and to focus on the comparison among different soil
amendment effects. Plant growth (shoot height, shoot biomass, root biomass and root C:N ratio), root
defense metabolites (phenolics) and their related genes expression, and soil properties including pH,
electrical conductivity, available nutrients, 3-indoleacetic acid (IAA), microbial biomass and activity were
analyzed at 14 and 30 days post inoculation (dpi). Compared with inorganic fertilizer, vermicompost
significantly decreased the numbers of nematode-induced galls on susceptible (Sus) and resistant (Res)
cultivar roots by 77% and 42% respectively at 14 dpi, and by 59% and 46% respectively at 30 dpi.
Vermicompost also significantly increased root defense metabolite concentrations, defense related gene
expression, and improved soil properties (p < 0.05) except for mineral nitrogen. Multivariate analyses
further indicated that soil properties particularly pH, root primary and secondary defense metabolites
were negatively associated with root gall. Moreover, soil microbial activity, pH and IAA concentration
were the main soil properties positively associated with plant defense metabolites production and
biomass for both susceptible and resistant cultivars. Overall, vermicompost could significantly suppress
root pests via modulating soil properties as well as plant defenses, particularly for the susceptible plant.
Original language | English |
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Pages (from-to) | 177 - 186 |
Number of pages | 10 |
Journal | Applied Soil Ecology |
Volume | 105 |
Early online date | 28 Apr 2016 |
DOIs | |
Publication status | First published - 28 Apr 2016 |
Keywords
- Cultivar trait
- Organic amendment
- Plant defense
- Resistance
- Root herbivore