Abstract
Field experiments were conducted in 1996 and 1997 with a marked strain of Pyricularia grisea to determine if inoculum from infested rice grain could cause primary infections and sustain a rice blast epidemic during the growing season by giving rise to leaf, collar, and neck symptoms. The marked strain, a sulfate nonutilizing (sul) mutant of P. grisea, was grown on autoclaved rice seed for 7 days at 25°C. Infested rice grains were applied to the soil surface at the time of plant emergence (approximately 10 days after planting) at densities of 0, 0.5, 5, 25, and 50 grains per 0.1 m 2 in plots planted to the blast susceptible cv. M-201. Leaf blast symptoms were first detected in the plots containing infested grain 35 days after plant emergence in both 1996 and 1997. The sul mutant was isolated from more than 90% of the lesions sampled from rice seedlings 35 to 45 days after plant emergence. Leaf blast increased more rapidly in plots with 25 and 50 infested grains per 0.1 m 2 than in plots with less inoculum pressure (0.5 and 25 infested grains per 0.1 m 2 ), although in 1996, leaf blast incidence recorded at midseason in plots containing 0.5 and 5 infested grains per 0.1 m 2 was 41 and 55%, respectively. At the end of both seasons, the sul mutant was recovered from over 90% of the leaf, collar, and neck blast lesions except for one sample date in 1996. Rice blast was not detected in the control plots (no infested grain) in 1997 and not until 65 days after planting in 1996. Comparisons of disease progress on leaves between the marked strain and the parental wild-type strain under field conditions indicated that development of disease caused by the sul mutant was similar to disease caused by the wild-type strain.
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Claims 8
Claim · model-written summary
Leaf blast first appeared in infested-grain plots 35 days after plant emergence in both years.
- Taxon
- Rice
Oryza sativat0 - Treatment
- infested graine0
- Outcome
- Leaf blast symptomse0
- Value
- 35 dayse0
- Setting
- plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf blast symptoms were first detected in the plots containing infested grain 35 days after plant emergence in both 1996 and 1997.”
t0“Rice Blast Epidemics Initiated by Infested Rice Grain”
Claim · model-written summary
The marked pathogen was isolated from more than 90% of sampled rice seedling lesions at 35–45 days after emergence.
- Taxon
- RiceOryza sativat0
- Interactor
- P. grisea
Pyricularia griseae1pathogen - Outcome
- sul mutant was isolatede0
- Value
- more than 90%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The sul mutant was isolated from more than 90% of the lesions sampled from rice seedlings 35 to 45 days after plant emergence.”
e1“a sulfate nonutilizing (sul) mutant of P. grisea”
t0“Rice Blast Epidemics”
Claim · model-written summary
Leaf blast increased more rapidly at 25 and 50 infested grains per 0.1 m 2 than under lower inoculum pressure.
- Taxon
- RiceOryza sativat0
- Treatment
- 25 and 50 infested grains per 0.1 m 2e0
- Outcome
- Leaf blaste0
- Direction
- increased more rapidlye0
- Comparator
- less inoculum pressuree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaf blast increased more rapidly in plots with 25 and 50 infested grains per 0.1 m 2 than in plots with less inoculum pressure (0.5 and 25 infested grains per 0.1 m 2 )”
t0“Rice Blast Epidemics”
Claim · model-written summary
In 1996, midseason leaf blast incidence was 41% at 0.5 infested grains per 0.1 m 2.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in 1996, leaf blast incidence recorded at midseason in plots containing 0.5 and 5 infested grains per 0.1 m 2 was 41 and 55%, respectively.”
t0“Rice Blast Epidemics”
Claim · model-written summary
In 1996, midseason leaf blast incidence was 55% at 5 infested grains per 0.1 m 2.
- Taxon
- RiceOryza sativat0
- Treatment
- 5 infested grains per 0.1 m 2e0
- Outcome
- leaf blast incidencee0
- Value
- 55%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in 1996, leaf blast incidence recorded at midseason in plots containing 0.5 and 5 infested grains per 0.1 m 2 was 41 and 55%, respectively.”
t0“Rice Blast Epidemics”
Claim · model-written summary
The marked mutant was recovered from over 90% of leaf, collar and neck blast lesions at the end of both seasons, apart from one 1996 sample date.
- Taxon
- RiceOryza sativat0
- Interactor
- P. griseaPyricularia griseae1pathogen
- Outcome
- sul mutant was recoverede0
- Value
- over 90%e0
- Qualifier
- except for one sample date in 1996e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At the end of both seasons, the sul mutant was recovered from over 90% of the leaf, collar, and neck blast lesions except for one sample date in 1996.”
e1“a sulfate nonutilizing (sul) mutant of P. grisea”
t0“Rice Blast Epidemics”
Claim · model-written summary
Rice blast was absent in untreated control plots in 1997 and appeared only 65 days after planting in 1996.
- Taxon
- RiceOryza sativae0
- Outcome
- Rice blast was not detectede0
- Value
- 65 dayse0
- Comparator
- control plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rice blast was not detected in the control plots (no infested grain) in 1997 and not until 65 days after planting in 1996.”
Claim · model-written summary
Disease development caused by the sul mutant was similar to that caused by the wild-type strain in field comparisons.
- Taxon
- RiceOryza sativat0
- Treatment
- sul mutante0
- Outcome
- development of diseasee0
- Direction
- similare0
- Comparator
- wild-type straine0
- Setting
- field conditionse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“development of disease caused by the sul mutant was similar to disease caused by the wild-type strain.”
e1“under field conditions”
t0“Rice Blast Epidemics”
The same questions in other papers
infection · disease · Oryza sativa (rice)Positive and negative results
12 papers in the same direction as this paper · 15 in the opposite direction
- negative
- positive
- positive
24 papers more in this group
See all 28 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.