Climatic constraints to yield and yield components of temperate japonica rice

Abstract

Although temperate japonica rice (Oryza sativa L.) production is limited by both low‐ and high‐temperature stresses, the primary constraint was reported to be cold stress in the past. However, the magnitudes of low‐ and high‐temperature stresses may have been altered by global warming. In this study, the major climatic constraints to the yield and yield components of temperate japonica rice grown in field conditions under the current climates were assessed using the random forests method with 14‐yr field trial data (n = 499). Low temperatures had negligible impacts on rice yield under the current climates (2005–2018) in South Korea. Meanwhile, high‐temperature stress was most significant during the ripening stage, followed by the reproductive stage. Yield losses by high temperatures were primarily associated with reduced filled‐grain percentage, followed by reduced 1,000‐grain weight. During the vegetative stage, higher temperature (or higher growing degree days, GDD) decreased the number of panicles per m2 and increased the number of spikelets per panicle, resulting in negligible changes in the number of spikelets per m2 and yield. The effect of solar radiation was most significant during the ripening stage. More solar radiation during the ripening stage enhanced rice yield by increasing filled‐grain percentage and 1,000‐grain weight. This study highlights that the primary constraints to temperate japonica rice grown under the current climates are high‐temperature stresses during the ripening and reproductive stages rather than low‐temperature stresses. Thus, there is an urgent need to explore options for improving the adaptation of temperate japonica rice to anticipated global warming.

Agronomic performance and selection of green super rice doubled haploid lines from anther culture

“…The SN47 and SN48 lines had a significantly lower percentage of filled grain than Inpari 42 Agritan GSR. According to Kim et al (2021), the percentage of filled grain might be affected by solar radiation during the grain ripening process. Meanwhile, Sadimantara et al (2018) stated that the grain yield was determined by the number of panicles per unit area, the fertility of the grains, the number of grains per panicle, and the weight of the grain.…”

“…SN46 and SN47 had WG significantly lower while two DH lines, namely SN59 and SN60 had WG significantly heavier than the Inpari 42 Agritan GSR. According to Kim et al (2021), the weight of 1000 grains was affected by solar radiation. A lot of solar radiation during the ripening stage can increase the yield of rice.…”

Responses of rice cultivars with different cold tolerance to chilling in booting and flowering stages: An experiment in Northeast China

“…The increasing demand of rice consumption coupled with the increasing intensity of extreme chilling events will challenge the rice production in the future (Kim et al, 2021). In order to achieve high and stable grain yield for rice, it is imperative to understand how rice cultivars are affected by chilling at various stages.…”