- Botany, Production and Uses
- The soybean : botany, production and uses
- The soybean: botany, production and uses - Semantic Scholar
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- The soybean: botany, production and uses
Full Name Comment goes here. Are you sure you want to Yes No. Tharuka Wijesekara. Pyush Salhotra. Show More. No Downloads. This figure is available in colour at JXB online. On the primary and lateral racemes of basal and central node positions photoperiod extension significantly increased the duration of the pod lag phase from 3 to 23 td depending on the photoperiod treatment and the node position within the plant Table 3. The same tendency was observed at the apical nodes, but it was not statistically significant.
The prolongation of the pod lag phase, in response to photoperiod extension, was stronger at the basal nodes compared to the central ones and on the primary racemes compared to the lateral ones. Shading also increased the pod lag phase at the basal and central nodes, but only on the primary racemes.
Mean pod lag phase duration of the first fruit on primary and lateral racemes at basal, central or apical nodes of the main stem of plants. These results indicate that both pod and embryo developments were delayed under extended photoperiods and that the internal ovule and embryo development correlate well with the length of the pod or seed.
External and internal development of the first reproductive organ on the primary raceme at a central main stem node of unshaded plants under control or 3h extended photoperiod in Exp2. Pods in the P 0 category from plants under extended photoperiod were collected successively every week until they reached the next category P 1. Boxed numbers are the days after R1 when each developmental state was reached.
External development bar, 1cm. Photoperiod extension increased pod number at usually dominated positions within the node lateral racemes and delayed pod elongation at dominant positions the primary raceme. To test the association between these two processes we analysed all the data using two-path analysis, one for the pods on primary racemes and another for pods on lateral racemes, including flowering duration and flower number data Fig. Two path diagrams showing causal relationships between: pod number on primary 5 and lateral racemes 6 and the component variables: pod lag phase duration 1 , flowering duration 2 and flower number on primary 3 and lateral racemes 4.
All variables are expressed on node basis and include basal, central and apical node data from both experiments. The double-arrowed lines indicate mutual association as measured by correlation coefficients r between two variables subscripts and the single-arrowed lines represent direct influence as measured by path coefficients. Additionally, the correlation between both response variables is shown.
The duration of the pod lag phase and flowering were correlated to each other and were also correlated with the number of opened flowers on each raceme Fig. Surprisingly, the correlation in the number of flowers with the duration of the pod lag phase was higher than its correlation with the duration of the flowering period.
In fact, within each node, flowering stopped when seed filling began data only available for Exp2 as the fitted relationship between these dates Fig. Relationship between time to last flower and time to first filling pod in thermal days, td at basal, central and apical nodes of the main stem of plants under full radiation filled symbols or shade empty symbols and control circles , 1. No significant correlation was found between flower and pod number on the primary raceme Table 4. However, pod number was negatively correlated with the duration of the flowering period and the pod lag phase.
These correlations were low but significant and were caused by the strong direct negative effect of the duration of the pod lag phase on pod set on primary racemes Supplementary Fig. Direct and indirect path coefficients of pod lag phase and flowering duration thermal days and flower number on pod number on primary or lateral racemes. Correlation and P -value of the correlation between the three variables associated with the dynamics of pod setting and pod number are given.
Otherwise, on the lateral racemes high and significant correlations were found between the three component variables pod lag phase, flowering duration and flower number and pod number Table 4. The number of flowers had a high correlation with pod number on lateral racemes that was mainly due to its direct effect. Flowering duration had a high correlation with pod number on lateral racemes due to its own direct effect and indirect effects mediated by the number of flowers.
The duration of the pod lag phase had a higher correlation with the number of pods on lateral racemes, mainly through its indirect effects through flowering duration and the number of flowers Supplementary Fig. Given the negative effect of the duration of the pod lag phase on the number of pods on primary racemes and the inverse positive effect on the number of pods on lateral racemes, a negative correlation is expected between the number of pods on primary and lateral racemes; however, this correlation was low.
Photoperiod affected pod number on lateral racemes through its effects on individual pod development pod lag phase duration. Our study revealed that photoperiod extension during post-flowering increased the number of pods per node, mainly by increasing pod number on the lateral racemes at some main stem nodes. Pod number on the lateral racemes was increased when photoperiod was extended because i more flowers opened and ii more pods set on those racemes. Photoperiod extension also delayed individual pod elongation and the beginning of seed filling, which started once the pods reached their maximum size.
More flowers opened on the lateral racemes, due to the extension of the flowering period associated with the delay in the effective seed filling period at that node on the primary racemes. These associations and possible photoperiodic effects on pod development that might increase pod number at the node level constitute a novel finding that is supported by many results of the present work.
In our experiments, reductions in incident radiation from flowering onwards only depressed flower production and pod setting at the basal nodes and these negative effects were diluted at the plant level. As expected, plants under an extended photoperiod had more pods per node on their main stems, as previously reported Guiamet and Nakayama, ; Morandi et al. This effect was observed in both experiments which were sown in different dates even though the environmental conditions and the number of nodes and pods per m 2 were different between experiments Nico et al.
A more detailed analysis at the node level at different positions of the main stem revealed that the magnitude and significance of the photoperiodic effect was variable between main-stem node positions, as recently reported by Kantolic et al. Additionally, we found a clear differential effect of long days on primary and lateral racemes that, to our knowledge, has not been previously reported. At some node positions the earliest flowering ones , photoperiod extension reduced pod number on the primary racemes but this negative photoperiodic effect was usually compensated by a positive effect on pod production on lateral racemes.
These findings suggest the existence of a compromise between pod set at dominant and dominated positions to maximize pod production at the node level. When exposed to long days after flowering, some soybean varieties have shown flowering reversion Han et al. However, no evidence of this phenomenon was observed in the present work, so photoperiodic effects on pod development were apparently not linked to flowering reversion.
In our experiments, the photoperiodic effect on pod number on lateral racemes was associated with increases in both the number of opened flowers and pod set. Van Schaik and Probst also found that long days increased the number of flowers per node but, in contrast to our work, pod set depended on the magnitude of the photoperiod extension and also the temperature : when photoperiods were too long or temperature was too high, the negative effect of flower and pod shedding cancelled the positive effect of enhanced flower production.
The number of opened flowers on primary racemes presented low variation as observed in the number of pods. In the present study, photoperiod extension treatments were imposed after R1, when flower differentiation culminates on primary racemes but continues on lateral racemes Saitoh et al. Thereby, we may not have observed any effect of photoperiod extension on the number opened flowers on primary racemes if this response was associated with the differentiation of flower primordia.
Besides the aforementioned effect of photoperiod, Egli and Bruening a also observed that at isolated nodes the number of flowers on the primary raceme seemed fixed at a relatively modest number, implying a relatively short flowering period, while the lateral racemes had a great potential to increase the length of the period and thereby to produce a large number of flowers per node.
Thus, the extension of the flowering period and the enhancement of flower number at the node level, seem to depend on the lateral racemes. At the whole plant level, a positive linear relationship between flowering duration and the number of flowers has been found when photoperiod was manipulated van Schaik and Probst, ; Summerfield et al. Under a natural photoperiod, Dybing found that the total number of flowers was more related to the flowering rate than to its duration.
At node level, we confirmed the positive relationship between flowering duration and the number of opened flowers, revealing that plants under long photoperiods have long flowering periods not just because they have more flowering nodes, but also because flowering lasts longer at each node. We found that the flowering period was extended due to the appearance of flowers on lateral racemes.
Unfortunately, Dybing — who found a weak relationship between flowering duration and the number of flowers — did not count the number of flowers on lateral racemes. At each node, the flowering period was prolonged in accord with the delay of pod development under long photoperiods.
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Egli and Bruening b also observed this association between flowering end and the beginning of the linear phase of seed growth at phloem-isolated soybean nodes. This correspondence was attributed to a competition between sinks because, when seeds enter into the linear phase of growth and accumulate assimilates at maximum rate, they become a relatively large reproductive sink that may limit flowering Spaeth and Sinclair, The simultaneous growth of pods of different hierarchies position and age has been postulated as a critical aspect of assimilate utilization Egli and Bruening, a.
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Even though flowers are normally produced in excess, the dynamics of flower production have been proposed as an important aspect in the complex process of pod and seed number determination. By delaying pod development, long days could be alleviating, or at least postponing, the interaction between dominant and dominated pods.
Photoperiod effects on pod elongation and node appearance might have modified the temporal dynamics of the source-sink ratio at the node level. However, Nico et al. Furthermore, the inhibition of late-appearing flowers or small pods by earlier or larger pods has been largely studied, and several mechanisms and putative signals have been proposed.
Huff and Dybing , propose that flower abortion could be caused by hormonal induction suggesting indoleacetic acid as the candidate hormone. Abscisic acid could also be involved, because it has an inhibitory role on flowering Bernier et al. Even though the interaction between dominant and dominated pods is evident, it is still not clear whether there is an optimal temporal flowering profile in soybean Egli, as both long Egli and Bruening, ; Kantolic and Slafer, and short flowering periods Egli and Bruening, a have been associated with increased pod set.
The soybean : botany, production and uses
The rapid increase in assimilate utilization by older pods make them the preferred sink and causes the abortion of late flowers at distal positions. Therefore, Egli and Bruening a proposed a strategy to increase pods per node synchronizing the production of many early flowers that would grow together rapidly. Therefore, these synchronous flowers were not only temporally uncoupled from pods in active growth but also spatially detached.
Our results suggest that there is another possible strategy to increase pod number per node based on the idea proposed by Egli and Bruening a. Instead of looking for more synchronous and earlier flowering at the dominated positions, we propose to obtain synchronous development delaying the growth of the dominant pods. Thus, more flowers will be already opened at the time of rapid pod and seed growth, and they would also grow together, although not rapidly. In fact, recent modelling with SOYPODP [a whole plant model that assembles SOYPOD node units by Egli ] revealed that lengthening the sensitive period of pod growth pod lag phase diminishes the competition for assimilates between pods of different age, increasing pod set and the number of pods per plant.
We suggest, based on our studies, that the delay in pod development when plants are exposed to long days increases the potential number of seeds through the avoidance of competition for assimilates or signals triggered during the beginning of active pod and seed growth. Post-flowering photoperiod extension effects were not alike during all pod developmental phases. We mentioned before that long days delayed seed filling, which begins once pods have reached their final length and width.
Photoperiod extension delayed the onset of pod elongation, prolonging the pod lag phase. Zheng et al. The photoperiodic prolongation of the pod lag phase was greater on those pods which also had longer pod lag phases under natural photoperiod according to their node position and raceme. As the natural photoperiod diminished when the crop season advanced and therefore the extended photoperiod did so as well , photoperiod was shorter when the later flowers opened.
Pod elongation after the pod lag phase continued similarly for primary and lateral racemes of all photoperiod and shading treatments in line with that reported by Zheng et al. These results observed at the individual pod level are in line with those observed at the plant or community level, where partitioning of assimilates to pods was delayed but afterwards continued at the same rate when photoperiod was extended Nico et al. Assuming that photoperiod is triggering a developmental elongation signal, the beginning of dry matter accumulation into pods and seeds could be uncoupled from the beginning of flowering, as suggested by Thomas and Raper This uncoupling could reproduce the effects observed on pod set when photoperiod is extended from flowering onwards and could be used as a favourable trait in soybean breeding programmes.
Some evidence of this independence has been found in other species. In groundnuts, photoperiod regulates the onset of pod growth but not flowering [ Arachis hypogaea in Flohr et al. In potato, flowering and tuberization are photoperiodically regulated by two members of the potato FT-like gene family that respond to different environmental cues Navarro et al.
In conclusion, our results suggest that long days during post-flowering enhance pod number per node alleviating the competition between pods of different hierarchy. The photoperiodic effect on dominant pod development, delaying their elongation and therefore postponing their active growth, extends flowering and allows pod set at usually dominated positions. Some questions are still unanswered in relation to the nature of the interaction between dominant and dominated pods: Are long days altering the competition for assimilates between dominant and dominated pods?
Or are they removing some sort of chemical inhibition? This is the subject of future research. Supplementary Fig. The dynamics of pod development presented in Fig. The relationship between the duration of the pod lag phase and pod number-determining variables. The relationship between pod lag phase duration and the photoperiod explored during the day the flower opened.
We thank P.
The soybean: botany, production and uses - Semantic Scholar
Lo Valvo, C. Pedace for their excellent field assistance and technician G. Zarlavsky for useful advice on the preparation of histological microscopic sections. National Center for Biotechnology Information , U.
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J Exp Bot. Published online Oct Mantese , 2 Daniel J. Miralles , 3 , 4 , 5 and Adriana G. Kantolic 1.
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Anita I. Daniel J. Adriana G. Author information Copyright and License information Disclaimer. E-mail: ra. Abstract In soybean, long days during post-flowering increase seed number. Key words: Development, elongation, embryo, flowering, fructification, Glycine max , lag phase, node, photoperiod, pod set, radiation, seed filling, shade, soybean. Introduction Soybean Glycine max L. Measurements and estimated variables At R1, three plants were tagged within each plot. Open in a separate window. Statistical analysis A mixed linear model was fitted to all measured and estimated data using the lme procedure of the nlme package Pinheiro et al.
Light microscopy In Exp2, flowers A , small pods P 1 and P 2 and transverse sections pods P 3 , P 4 and BF were collected as they appeared on primary racemes of central nodes of unshaded plants under control or 3h extended photoperiod. Table 1. Table 2. Dynamics of flowering and pod development at the node level As treatments were imposed immediately after the beginning of flowering R1 , flower opening at successive upper nodes advanced alongside under both photoperiodic and shading treatments.
Table 3. Relationship between pod development and pod number Photoperiod extension increased pod number at usually dominated positions within the node lateral racemes and delayed pod elongation at dominant positions the primary raceme. Table 4. Discussion Our study revealed that photoperiod extension during post-flowering increased the number of pods per node, mainly by increasing pod number on the lateral racemes at some main stem nodes.
Supplementary Data: Click here to view. Acknowledgements We thank P. Physiological signals that induce flowering. The Plant Cell 5 , — Assimilatory capacity effects on soybean yield components and pod number. Crop Science 35 , — Source strength influence on soybean yield formation during early and late reproductive development. Influence of photoperiods upon the differentiation of meristems and the blossoming of Biloxi soybeans. Botanical Gazette 99 , — Rates of progress towards flowering and podding in Bambara Groundnut Vigna subterranea as a function of temperature and photoperiod.
The soybean: botany, production and uses
Annals of Botany 80 , — Relationship between photosynthesis and seed number at phloem isolated nodes in soybean. Crop Science 39 , — Leaf starch accumulation and seed set at phloem-isolated nodes in soybean. Field Crops Research 68 , — Plant Physiology 75 , — Reproductive morphology. Soybeans: Improvement, Production, and Uses. Buenos Aires: Hemisferio Sur. Growth, yield, and yield component changes among old and new soybean cultivars.
Agronomy Journal , — Soybean flower production as related to plant growth and seed yield. Crop Science 34 , — Cultivar maturity and response of soybean to shade stress during seed filling. Field Crops Research 52 , 1—8. Seed biology and the yield of grain crops. CAB International: Madison. Flowering, pod set and reproductive success in soya bean. Journal of Agronomy and crop science , — Control of seed growth in soya beans.
Annals of Botany 48 , — Crop growth rate and seeds per unit area in soybean. Crop Science 31 , — Potential of early-maturing soybean cultivars in late plantings. Agronomy Journal 92 , — Crop Science 42 , — Field Crops Research 79 , 9— European Journal of Agronomy 24 , 11— Field Crops Research 98 , — Stages of soybean development. Ames, Iowa.
NC Ac Experimental Agriculture 26 , — Bloom and pod set in determinate and indeterminate soybeans grown in China.
Agronomy Journal 76 , — The effects of long days upon reproductive growth in soybeans Glycine max L. Japanese Journal of Crop Science 53 , 35— Effects of temperature and photoperiod on flowering in soya bean Glycine max L. Merrill : a quantitative model. Annals of Botany 53 , — Discovery of flowering reversion in soybean plants.