Is the yield change due to warming affected by photoperiod sensitivity? Effects of the soybean E4 locus

Abstract

Modeling studies predict that global warming will shorten growth duration and reduce seed yield of early‐maturing soybean (Glycine max) cultivars, but that late‐maturing cultivars could mitigate this reduction. This is widely discussed but has not been validated experimentally. Time of soybean maturation is determined by several photoperiod‐sensitive loci. Here, we focused on the E4 locus, and tested the hypothesis that this locus would mitigate the growth period shortening and yield reduction due to warming. We sowed cv. Enrei with the dominant E4 allele and a near‐isogenic line with recessive e4 allele (NIL‐e4) on two dates (normal vs. late, with a shorter photoperiod) and grown under three temperature regimes (near‐ambient, and 2.0 and 4.6°C above ambient) in sunlit greenhouses in a cool region of Japan. The period from sowing to flowering (R1) decreased with increasing temperature, regardless of genotype and sowing date. However, increased temperature prolonged the period from R1 to the beginning of pod filling (R3) in Enrei but not in NIL‐e4 for either sowing date. This indicates that increasing temperature shortened the period before R1, exposing Enrei with E4 to a longer photoperiod and therefore slowing its development. For both sowing dates, pod number and seed yield increased with warming in Enrei. Since the days from R1 to R3 and the cumulative radiation for this period were positively correlated with pod number in Enrei, the greater yield response was explained mostly by the prolongation of this period caused by warming. However, the yield increase resulted partially from the current mean growing season temperature, which was near or below the optimum for yield. We conclude that the E4 locus can increase seed yield under future warming in cool regions of Japan. This result demonstrates the potential importance of modifying photoperiod sensitivity to increase soybean yield under future warming.

Agricultural practice contributed more to changes in soybean yield than climate change from 1981 to 2010 innortheastChina

“…36 Changing to a variety with higher heat time requirements (thus prolonging the growth period) can therefore stabilize soybean yield. 37 Similar countermeasures have been reported for maize in the corn belt of the USA, 38 winter wheat in China, 13 and cotton on the North China Plain. 39 Numerous previous studies based on statistical or crop modeling have reported negative impacts of global warming on crop yields.…”

“…Increasing temperatures accelerate soybean growth and shorten the vegetative and reproductive growth stages, 34 a simulation study found that a reduction in soybean filling days of nearly 8% due to warming 36 . Changing to a variety with higher heat time requirements (thus prolonging the growth period) can therefore stabilize soybean yield 37 . Similar countermeasures have been reported for maize in the corn belt of the USA, 38 winter wheat in China, 13 and cotton on the North China Plain 39 .…”

Soybean (Glycine max (L.) Merr.) Yield Reduction due to Late Sowing as a Function of Radiation Interception and Use in a Cool Region of Northern Japan

“…The partial correlation coefficient between mean temperature and seeds per pod with a fixed mean FASW during the 20 days after R5 was 0.864 (p < 0.001). Although the number of seeds per pod remains stable under a wide range of temperatures [32], Kurosaki and Yumoto [33] report that low temperature (15.5 • C mean temperature) for four weeks in the flowering season reduced the number of seeds per pod in soybean cultivars in Hokkaido (the northernmost prefecture in Japan). In this study, the mean temperature was 22.6 • C during the period from R2 to R5 and 19.3 • C for the 20 days after R5 in the late-sown soybeans.…”

Long-Term Dynamic of Cold Stress during Heading and Flowering Stage and Its Effects on Rice Growth in China

“…Increasing temperature can accelerate the growth cycle, leading to earlier senescence, and decrease both canopy radiation capture and biomass [42]. Kumagai et al (2020) [43] also found crop phenological stages responded differently to increasing temperature; specifically, increased temperature shortened the period from emergence to flowering and grain filling to maturity but prolonged the period during heading and flowering. Our study found the actual lengths during heading and flowering had an increasing trend at 0.11 day•yr −1 , 0.38 day•yr −1 and 0.20 day•yr −1 in NEP, YNP and SMLYR, respectively (Table 3), which indicated that increasing temperature has shortened the period before heading or after flowering.…”