Abstract
Sub-optimal night temperatures below 15 degrees C (dark chilling) frequently reduce soybean [Glycine max (L.) Merrill] production. Nitrate application is known to alleviate some of the negative effects of low root zone temperatures, probably by counteracting the inhibition caused by decreased symbiotic nitrogen fixation (SNF). Under field conditions, however, dark chilling is frequently not accompanied by low root zone temperatures. The possibility that nitrate might increase dark-chilling tolerance under these conditions is still largely unexplored. In addition to quantifying vegetative development by means of the plastochron index, O-J-I-P (O-I(1)-I(2)-P) chlorophyll a fluorescence transients were recorded in soybean genotypes of contrasting chilling tolerance during and following exposure to dark chilling in the absence of low root zone temperatures. Plants, inoculated with the N(2)-fixing bacteria, Bradyrhizobium japonicum, were grown with and without nitrate supplementation. The recorded O-J-I-P chlorophyll a fluorescence transients were analysed by the so-called JIP-test which translates stress-induced alterations in these transients to changes in biophysical parameters that quantifies the energy flow through photosystem II (PSII). One of these parameters, the performance index (PI(ABS)), combines the three main functional steps (light energy absorption, excitation energy trapping, and conversion of excitation energy to electron transport) of photosynthetic activity by a PSII reaction centre complex into a single multiparametric expression. By using the PI(ABS) we could convincingly show that nitrate supplementation considerably enhances dark-chilling tolerance and recovery capacity of plants in the absence of low root zone temperatures. This was especially true for the chilling-sensitive genotype ('Java 29'), suggesting that the response of SNF to dark chilling might be an important factor contributing towards genotypic differences in chilling tolerance. Our results corroborated previous reports about the superior chilling tolerance of 'Maple Arrow', a chilling-tolerant genotype. The results obtained indicated that the PI(ABS) is a far more sensitive indicator of dark-chilling stress than the maximum quantum yield of primary photochemistry (F(V)/F(M)).
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 5
Claim · model-written summary
Nitrate supplementation enhances soybean dark-chilling tolerance without low root zone temperatures.
- Taxon
- soybean
Glycine maxe0 - Treatment
- nitrate supplementatione1
- Outcome
- dark-chilling tolerancee1
- Direction
- enhancese1
- Qualifier
- in the absence of low root zone temperaturese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [Glycine max (L.) Merrill]”
e1“By using the PI(ABS) we could convincingly show that nitrate supplementation considerably enhances dark-chilling tolerance and recovery capacity of plants in the absence of low root zone temperatures.”
Claim · model-written summary
Nitrate supplementation enhances soybean recovery capacity without low root zone temperatures.
- Taxon
- soybeanGlycine maxe0
- Treatment
- nitrate supplementatione1
- Outcome
- recovery capacitye1
- Direction
- enhancese1
- Qualifier
- in the absence of low root zone temperaturese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean [Glycine max (L.) Merrill]”
e1“By using the PI(ABS) we could convincingly show that nitrate supplementation considerably enhances dark-chilling tolerance and recovery capacity of plants in the absence of low root zone temperatures.”
Claim · model-written summary
Nitrate benefit was especially strong in chilling sensitive Java 29.
- Taxon
- soybeanGlycine maxe0
- Material
- Java 29e1
- Outcome
- chilling tolerancee1
- Qualifier
- especially truee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean genotypes of contrasting chilling tolerance”
e1“This was especially true for the chilling-sensitive genotype ('Java 29'), suggesting that the response of SNF to dark chilling might be an important factor contributing towards genotypic differences in chilling tolerance.”
Claim · model-written summary
Maple Arrow showed superior chilling tolerance.
- Taxon
- soybeanGlycine maxe0
- Material
- Maple Arrowe1
- Outcome
- chilling tolerancee1
- Direction
- superiore1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean genotypes of contrasting chilling tolerance”
e1“Our results corroborated previous reports about the superior chilling tolerance of 'Maple Arrow', a chilling-tolerant genotype.”
Claim · model-written summary
PI(ABS) was more sensitive to dark chilling than F(V)/F(M).
- Taxon
- soybeanGlycine maxe0
- Outcome
- sensitive indicator of dark-chilling stresse1
- Direction
- far more sensitivee1
- Comparator
- maximum quantum yield of primary photochemistry (F(V)/F(M))e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“soybean genotypes of contrasting chilling tolerance”
e1“The results obtained indicated that the PI(ABS) is a far more sensitive indicator of dark-chilling stress than the maximum quantum yield of primary photochemistry (F(V)/F(M)).”
The same questions in other papers
nitrogen · disease · Glycine max (soybean)Positive and negative results
6 papers in the same direction as this paper · 4 in the opposite direction
- negative
- negative
- no effect
7 papers more in this group
See all 11 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.