Soybean seed weight responds to increases in assimilate supply during late seed-fill phase

Abstract

The understanding of source-sink dynamics during reproductive stages is essential to increase crop productivity and to describe yield component determination in eco-physiological models. Previous studies in soybean (Glycine max [L.] Merr.) evaluated the effect of changes in assimilate supply from the beginning of rapid seed growth but not at different times during the seed-filling phase or at the single-pod level. Two source-sink manipulation experiments were conducted in the greenhouse to quantify the effect of assimilate supply during the seed-filling phase on final seed weight of soybean. One pod on each node containing 3 mm seeds was marked in all plants, and pods not marked were removed at weekly intervals to avoid sink competition for assimilates. Removing pod competition on the day of marking and up to 21 days later increased final seed weight in marked pods by 25% relative to the control and by 18% when pod competition was removed 28 days after marking. Pods acquired mature color 33-35 days after marking. At 21 and 28 days after marking of individual pods, seeds had achieved 73% and 97% of their final seed weight and had 67 and 62% moisture, respectively. Our study provides new evidence that the final seed weight can still respond to increases in assimilate supply applied by the end of the seed-filling phase. These results highlight the potential to increase soybean yield through management practices and breeding efforts that extend the duration of a photosynthetically active canopy and increase assimilate supply to developing seeds during late seed-fill.

Growth Response of Two Soybean (Glycine Max (L.) Merr) Varieties Denna 1 And Rajabasa Subjected to Radiation Mutation Technique

“…The effect of the dose orientation treatment of gamma rays. It can also be concluded that the higher the radiation dose given, the plant's ability to produce leaves is also reduced [6]. As for the 0 Gy or control doses, 200 Gy, 300 Gy, 400 Gy had a lower average number of leaves.…”

“…Expansion of the planting area can be achieved by utilizing the unproductive lands, sub-optimal lands and shaded lands [5]. In line with these problems, planting shade-tolerant soybeans as intercrops is considered as one of the efforts that can be taken to increase land productivity [6]. while, increasing the production of broad meaning, including by using high-yielding varieties assembled through plant breeding programs.…”

Final Seed Size in Soybean Is Determined during Mid-Seed Filling Stage

“…In all of the previous field studies in soybean, source and sink were manipulated across the entire pod growth period. A recent study in a greenhouse setting [34] employing increased assimilate supply during different seed filling stages found that soybean seed size responds to an increase in assimilate supply until the late seed filling phase. This result suggests that seed size in soybean is determined during the late seed filling stage.…”

Genetic variation in four maturity genes and photoperiod insensitivity effects on the yield components and on the growth duration periods of soybean

“…In conditions of unfavourable day length, insufficient flow of assimilation products to growth points with a lower intensity of their accumulation and outflow leads to later formation of generative organs (Hider & Zhmurko, 2020). It has also been shown that in the field, the final weight of the seed can reach 68% to 85% of its potential, depending on environmental conditions (Chiluwal et al, 2021). The starch content of the seed is a decisive factor affecting the quality of soybean food products.…”