Responses of Grain Yield and Yield Related Parameters to Post-Heading Low-Temperature Stress in Japonica Rice

Abstract

There is unprecedented increase in low-temperature stress (LTS) during post-heading stages in rice as a consequence of the recent climate changes. Quantifying the effect of LTS on yields is key to unraveling the impact of climatic changes on crop production, and therefore developing corresponding mitigation strategies. The present research was conducted to analyze and quantify the effect of post-heading LTS on rice yields as well as yield and grain filling related parameters. A two-year experiment was conducted during rice growing season of 2018 and 2019 using two Japonica cultivars (Huaidao 5 and Nanjing 46) with different low-temperature sensitivities, at four daily minimum/maximum temperature regimes of 21/27 °C (T1), 17/23 °C (T2), 13/19 °C (T3) and 9/15 °C (T4). These temperature treatments were performed for 3 (D1), 6 (D2) or 9 days (D3), at both flowering and grain filling stages. We found LTS for 3 days had no significant effect on grain yield, even when the daily mean temperature was as low as 12 °C. However, LTS of between 6 and 9 days at flowering but not at filling stage significantly reduced grain yield of both cultivars. Comparatively, Huaidao 5 was more cold tolerant than Nanjing 46. LTS at flowering and grain filling stages significantly reduced both maximum and mean grain filling rates. Moreover, LTS prolonged the grain filling duration of both cultivars. Additionally, there was a strong correlation between yield loss and spikelet fertility, spikelet weight at maturity, grain filling duration as well as mean and maximum grain filling rates under post-heading LTS (p < 0.001). Moreover, the effect of post-heading LTS on rice yield can be well quantified by integrating the canopy temperature (CT) based accumulated cold degree days (ACDDCT) with the response surface model. The findings of this research are useful in modeling rice productivity under LTS and for predicting rice productivity under future climates.

Extreme Low-Temperature Stress Affects Nutritional Quality of Amino Acids in Rice

“…Furthermore, the increase in amino acid content was also due to the dilution effect caused by decreasing grain yield under LTS at the flowering stage. Our previous results with this same experiment showed that LTS after flowering did not significantly decrease grain weight, except under D3T4 treatment in Nanjing 46 ( Ali et al, 2021 ). And this result was similar to the previous studies ( Huang et al, 2021 ; Shi et al, 2021 ).…”

“…And this result was similar to the previous studies ( Huang et al, 2021 ; Shi et al, 2021 ). Therefore, we assume that the main reason for the dilution effect of the amino acids content could be the decreasing grain number due to reduced seed-setting rate under LTS, as reported in our previous study ( Ali et al, 2021 ), and the decreasing grain number under LTS could significantly reduce the sink capacity. Moreover, the nitrogen uptake of rice under LTS maintains to a larger extent ( Jia et al, 2015a ).…”

“…Environment-controlled phytotron experiments with two rice varieties, namely, Huaidao 5 and Nanjing 46, were conducted from 2018 to 2020 at Rugao Base (32°16N, 120°45E) in Jiangsu Province, China. Under LTS, the Nanjing 46 cultivar showed a larger reduction in grain yield compared to the Huaidao5 cultivar., indicating that Nanjing 46 was more sensitive to LTS than Huaidao 5 ( Ali et al, 2021 ). Seeds were sown in May in a nearby field ( Table 1 ) and raised on a dry seedbed.…”

Impacts of chilling at the tillering phases on rice growth and grain yield in Northeast China

“…The phenology change led to different pre‐ and post‐flowering photosynthetic contribution to aboveground biomass accumulation (Venkateswarlu and Prasad, 1980). In addition, the relatively low temperature during flowering and grain filling period for the chilling treatment at the tillering phases resulted in source‐sink relationship change and grain filling rate decrease (Tao et al, 2006; Gong et al, 2013; Shi et al, 2016; Ali et al, 2021) and finally decreased rice yield. Previous study also suggested different response of rice growth to temperature at pre‐ and post‐flowering phases (Zhang et al, 2020).…”

Genetic and molecular factors in determining grain number per panicle of rice

“…Hence, the environment conditions and cultivation methods also have significant effect on GN. High temperatures occurring at flowering and young microspore stages cause decrease of GN in rice due to spikelet degeneration and decreased pollen viability ( Hu et al, 2021 ; Park et al, 2021 ); while chilling stress also results in reduced GN through impairing pollen germination and reducing spikelet fertility ( Zeng et al, 2017 ; Hussain et al, 2018 ; Ali et al, 2021 ). Water stress during the meiosis stage leads to a severe reduction (40–45%) in GN due to pre-flowering spikelet abortion ( Kato et al, 2008 ; Yang et al, 2019 ).…”