Rice responses to rising temperatures – challenges, perspectives and future directions

Abstract

Phenotypic plasticity in overcoming heat stress-induced damage across hot tropical rice-growing regions is predominantly governed by relative humidity. Expression of transpiration cooling, an effective heat-avoiding mechanism, will diminish with the transition from fully flooded paddies to water-saving technologies, such as direct-seeded and aerobic rice cultivation, thus further aggravating stress damage. This change can potentially introduce greater sensitivity to previously unaffected developmental stages such as floral meristem (panicle) initiation and spikelet differentiation, and further intensify vulnerability at the known sensitive gametogenesis and flowering stages. More than the mean temperature rise, increased variability and a more rapid increase in nighttime temperature compared with the daytime maximum present a greater challenge. This review addresses (1) the importance of vapour pressure deficit under fully flooded paddies and increased vulnerability of rice production to heat stress or intermittent occurrence of combined heat and drought stress under emerging water-saving rice technologies; (2) the major disconnect with high night temperature response between field and controlled environments in terms of spikelet sterility; (3) highlights the most important mechanisms that affect key grain quality parameters, such as chalk formation under heat stress; and finally (4), we model and estimate heat stress-induced spikelet sterility taking South Asia as a case study.

Quantifying the Agronomic and Economic Performance of Hybrid and Conventional Rice Varieties

“…Third, when accounting for both paddy yield and milling quality, hybrids appear to be economically superior to conventional lines in both total profits and profit margins. Lastly, climate (specifically, exposure to high nighttime temperatures) can reduce HRY, further supporting previous findings (Cooper et al, 2006;Jagadish et al, 2014;Shi et al, 2013Shi et al, , 2015.…”

Plant Physiological, Morphological and Yield-Related Responses to Night Temperature Changes across Different Species and Plant Functional Types

“…Rustad et al (2001) conducted a meta-analysis of experimental data from ecosystem warming studies and found that elevated temperatures significantly increased above ground productivity by 19%. In fact, the effects of night temperature are different from that of day temperature (Xia et al, 2014) and produced a relatively greater challenge in estimating global change impact on crop yield and ecosystem functions (Jagadish et al, 2015). Previous studies on night temperatures have focused either on the effects of HNT and LNT alone (Friend, 1981; Seddigh and Jolliff, 1984a,b,c; Koscielniak, 1993; Bertamini et al, 2005) or the mixed effects of night temperatures and CO 2 concentration (Mortensen and Moe, 1992; Volder et al, 2004; Cheng et al, 2008, 2009, 2010), light period (Gimenez and Rumi, 1988; Turner and Ewing, 1988; Lee et al, 1991; Verheul et al, 2007), intensity (Bunce, 1985; Mortensen, 1994; Rapacz, 1998; Flexas and Osmond, 1999; Davies et al, 2002) as well as other environmental factors (Schoppach and Sadok, 2013) and growth regulators (Shah et al, 2011; Mohammed et al, 2013; Zhang et al, 2014).…”

Incidence of the mechanized sowing speed in irrigated rice

“…During this phase, plots sown at 3 km/h had a higher moisture content (plots with lower plants population). Temperatures may affect pollen formation, grain fertility [34], and decrease potential yields by up to 50% [35]. No significant differences were found for plant length.…”