Abstract
Abstract Rhizoctonia‐resistant sugar beet varieties are the key to an integrated control strategy for Rhizoctonia root rot. Because of the unpredictable occurrence of Rhizoctonia solani in the field testing of sugar beet for resistance to Rhizoctonia root rot is difficult. The aim of the study was to develop advanced greenhouse and field techniques which allow a reliable assessment of sugar beet for resistance to R. solani. A highly infectious liquid inoculum was used for the first time in this study. It can be produced in large quantities of a standardized quality, sterile, and exactly quantified according to its carbon content. In a greenhouse trial, sugar beet grown in the same way as field grown beet was inoculated by applying a suspension of Rhizoctonia mycelium (equivalent to 10 mg carbon per plant) to the beet crown. After 3 weeks, inoculation had led to uniform and severe root rot. Disease symptoms were similar to those found under natural conditions in the field. No ‘escapes’, i.e. susceptible plants apparently expressing resistance were observed in the test. A new nine‐class disease scale was established and a Rhizoctonia index (RI) was calculated. Reliability of disease assessment was demonstrated on progeny of plants, selected from segregating populations, showing Rhizoctonia resistance more closely related to the resistant parent lines than to the susceptible ones. Sugar beet varieties could be assessed in the greenhouse within only 11 weeks. All varieties were affected by the pathogen but partially resistant varieties could be clearly recognized by a significantly lower Rhizoctonia index. Significant differences in susceptibility were also found within the group of new resistant genotypes. Infection studies performed in the field showed the superiority of the new liquid inoculum compared with a solid form and revealed the influence of inoculation date and inoculum level on the development of Rhizoctonia root rot. In field tests performed at different sites under different environmental conditions, susceptible and partially resistant sugar beet varieties could be reproducibly rated according to their susceptibility to R. solani. On average, susceptible varieties showed a Rhizoctonia index of 8 while resistant genotypes ranged from 5 to 6. The newly developed techniques allow fast and reliable evaluation of sugar beet for resistance to R. solani.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 14
Claim · model-written summary
Liquid inoculum could be made in standardized, sterile, carbon-quantified quantities.
- Value
- large quantitiese0
Verbatim
e0“It can be produced in large quantities of a standardized quality, sterile, and exactly quantified according to its carbon content”
t0“sugar beet”
Claim · model-written summary
Liquid inoculation produced uniform severe root rot after three weeks.
- Taxon
- sugar beet
Beta vulgaris subsp. vulgarise0t0 - Treatment
- inoculatione0
- Direction
- severee0
- Value
- 3 weekse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“After 3 weeks, inoculation had led to uniform and severe root rot”
t0“sugar beet”
Claim · model-written summary
Greenhouse symptoms resembled natural field symptoms.
Verbatim
e0“Disease symptoms were similar to those found under natural conditions in the field”
t0“sugar beet”
Claim · model-written summary
The test showed no apparent resistant escapes among susceptible plants.
- Value
- No ‘escapes’e0
Verbatim
e0“No ‘escapes’, i.e. susceptible plants apparently expressing resistance were observed in the test”
t0“sugar beet”
Claim · model-written summary
Progeny of resistant selections resembled resistant parents more than susceptible lines.
Verbatim
e0“progeny of plants, selected from segregating populations, showing Rhizoctonia resistance more closely related to the resistant parent lines than to the susceptible ones”
t0“sugar beet”
Claim · model-written summary
The greenhouse method assessed sugar beet varieties in 11 weeks.
- Taxon
- Sugar beetBeta vulgaris subsp. vulgarise0t0
- Value
- 11 weekse0
- Setting
- greenhousee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Sugar beet varieties could be assessed in the greenhouse within only 11 weeks”
t0“sugar beet”
Claim · model-written summary
All tested sugar beet varieties were affected by the pathogen.
- Taxon
- sugar beetBeta vulgaris subsp. vulgarise0t0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All varieties were affected by the pathogen”
t0“sugar beet”
Claim · model-written summary
Partially resistant varieties had significantly lower Rhizoctonia index values.
- Taxon
- sugar beetBeta vulgaris subsp. vulgarise0t0
- Direction
- lowere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“partially resistant varieties could be clearly recognized by a significantly lower Rhizoctonia index”
t0“sugar beet”
Claim · model-written summary
New resistant genotypes differed significantly in susceptibility.
- Taxon
- sugar beetBeta vulgaris subsp. vulgarise0t0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Significant differences in susceptibility were also found within the group of new resistant genotypes”
t0“sugar beet”
Claim · model-written summary
Liquid inoculum outperformed solid inoculum in field infection studies.
Verbatim
e0“Infection studies performed in the field showed the superiority of the new liquid inoculum compared with a solid form”
t0“sugar beet”
Claim · model-written summary
Inoculation date and inoculum level influenced Rhizoctonia root rot development.
- Taxon
- sugar beetBeta vulgaris subsp. vulgarise0t0
- Treatment
- inoculation date and inoculum levele0
- Direction
- influencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“revealed the influence of inoculation date and inoculum level on the development of Rhizoctonia root rot”
t0“sugar beet”
Claim · model-written summary
Field tests reproducibly ranked susceptible and partially resistant varieties for R. solani susceptibility.
- Taxon
- sugar beetBeta vulgaris subsp. vulgarise0t0
- Value
- reproducibly ratede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“susceptible and partially resistant sugar beet varieties could be reproducibly rated according to their susceptibility to R. solani”
t0“sugar beet”
Claim · model-written summary
Susceptible varieties averaged Rhizoctonia index 8.
- Taxon
- sugar beetBeta vulgaris subsp. vulgarise0t0
- Value
- 8e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“susceptible varieties showed a Rhizoctonia index of 8”
t0“sugar beet”
Claim · model-written summary
Resistant genotypes had Rhizoctonia index values of 5 to 6.
- Taxon
- sugar beetBeta vulgaris subsp. vulgarise0t0
- Value
- 5 to 6e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“susceptible varieties showed a Rhizoctonia index of 8 while resistant genotypes ranged from 5 to 6”
t0“sugar beet”
The same questions in other papers
inoculation · disease · Beta vulgaris (beet)Positive and negative results
16 papers in the same direction as this paper · 7 in the opposite direction
- positive
- positive
- positive
20 papers more in this group
See all 24 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.