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A Rapid Tomato Seedling Assay for Verticillium Wilt
Author(s) -
Madhosingh C.
Publication year - 1996
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/j.1439-0434.1996.tb01501.x
Subject(s) - biology , fusarium wilt , verticillium wilt , wilting , seedling , incubation , wilt disease , horticulture , verticillium dahliae , fusarium oxysporum , cultivar , bacterial wilt , botany , biochemistry
A rapid (10‐min) tomato seedling assay was developed for determining the wilt‐capacity of cell‐free culture filtrates of race 1 and race 2 isolates of Verticiilium dahliae. The assay also rapidly determined the differences in wilt resistance between tomato cultivars. Rapidity was attained by manipulating incubation conditions to promote rapid wilting. These included inducing elongated stems in the susceptible cv. Bonny Best seedlings by growth of plants in subdued light (2.2 × 10 2 lux) and by concentrating two‐fold the cell‐free culture filtrates of the pathogen. Further, rapid uptake of the wilt factors in the culture filtrates was facilitated during incubation by increasing transpiration with bright light (23.8 × 10 3 lux), a wind stream (125–150 metres/min) across the assay seedlings, low relative humidity (28%) and a relatively high assay temperature (30 C). When necessary, these conditions were altered to extend the assay times. This assay system was used to determine optimal incubation time, temperature and medium for obtaining culture filtrates with increased wilt capacities. The assay also determined the relative wilt capacities of races 1 and 2 and the comparative resistance of four tomato cultivars to wilt caused by races 1 and 2.