Abstract
The global avocado industry is growing, and farmers are seeking to expand their plantations. However, many lands suitable for avocado planting were previously cultivated with hosts of the soil-borne fungal pathogen Verticillium dahliae, which is the causal agent of Verticillium wilt (VW). VW can seriously impair avocado orchards, and therefore, planting on infested soil is not recommended. The use of different rootstock types allows avocado cultivation in various regions with diverse biotic and abiotic constraints. Hence, we tested whether genetic variance among rootstocks may also be used to manage avocado VW. Six hundred trees, mostly Hass and some Ettinger, grafted on 23 selected rootstocks were evaluated for five years in a highly V. dahliae-inoculated plot for VW symptoms, fungal infection, and productivity. The selected rootstocks displayed a significant variation related to VW tolerance, and productive avocado rootstocks with potential VW tolerance were identified. Moreover, the rootstock productivity appears to correlate negatively to the susceptibility level. In conclusion, planting susceptible rootstocks (e.g., VC66, VC152, and VC26) in infested soil increases the likelihood of massive tree loss and low productivity. Whereas, tolerant rootstocks (e.g., VC804 and Dusa) may restrict VW and enable avocado cultivation on infested soils.
Highlights
The global avocado (Persea americana Mill.) market is constantly growing, with the harvested area tripled in the last two decades (FAOSTAT data)
The pathogen V. dahliae survives in the soil as microsclerotia for prolonged periods of over 20 years [8,9]
We evaluated whether genetic variance may be used to overcome avocado Verticillium wilt (VW)
Summary
The global avocado (Persea americana Mill.) market is constantly growing, with the harvested area tripled in the last two decades (FAOSTAT data). Avocado growers are constantly seeking to expand their orchards. Many agricultural lands suitable for avocado were previously used for the cultivation of crops that are hosts of the fungal soil-borne pathogen Verticillium dahliae. As a result of crop rotation history, using susceptible hosts, many soils are suspicious for V. dahliae infestation [7]. The pathogen V. dahliae survives in the soil as microsclerotia for prolonged periods of over 20 years [8,9]. The microsclerotia germinate and invade the host roots [10]. Mycelium develops in the root cortex and enters the xylem vessels [11], where produced conidia spread up to the host canopy [10]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call