Characterization of heat tolerance in wheat cultivars and effects on production components

Abstract

There is a need for heat tolerant wheat cultivars adapted to the expansion of cultivation areas in warmer regions due to the high demand of this cereal for human consumption. The objective of this study was to evaluate the effect of high temperatures on grain yield and yield components of wheat and characterize heat tolerant wheat genotypes at different development stages. The genotypes were evaluated in the field with and without heat stress. High temperatures reduced the number of spikelets per spike (21%), number of grains per spike (39%), number of grains per spikelet (23%), 1000-grain weight (27%) and grain yield (79%). Cultivars MGS 1 Aliança, Embrapa 42, IAC 24-Tucuruí and IAC 364-Tucuruí III are the most tolerant to heat stress between the stages double ridge and terminal spikelet; MGS 1 Aliança, BRS 264, IAC 24-Tucuruí, IAC 364-Tucuruí III and VI 98053, between meiosis and anthesis; and BRS 254, IAC-24-Tucuruí, IAC-364-Tucuruí III and VI 98053, between anthesis and physiological maturity. High temperatures reduce grain yield and yield components. The number of grains per spike is the most reduced component under heat stress. The genotypes differed in tolerance to heat stress in different developmental stages.

Sustainable and technological strategies for basic cereal crops in the face of climate change: A literature review

“…Ji et al (2017) analyzed the impact of low temperatures on wheat yield, identified the stages of ear formation and grain filling as being of greater sensitivity in cultivars of controlled environment. With the same conclusions but for high temperatures, Pimentel et al (2015) observed the 79% reduction in yield. Boutraa et al (2015) evaluated the growth of Saudi wheat under heat stress in a controlled environment, observing a reduction in physiological and growth indicators.…”

Componentes produtivos do trigo em função da temperatura no período de diferenciação de espiguetas

“…Embora os componentes de produção de plantas de trigo não tenham diferido entre as duas temperaturas testadas, houve diferença significativa entre as cultivares. A diferença entre as cultivares já era esperada diante do conhecimento sobre a variabilidade genética dentro da cultura (CARGNIN et al 2006, MACHADO et al 2010, FAROOQ et al 2011, OLIVEIRA et al 2011) e a influência do genótipo sobre componentes como número de espiguetas por espiga, grãos por espiga e grãos por espigueta (PIMENTEL et al 2015), entre outros fatores.…”

Potential area and limitations for the expansion of rainfed wheat in the Cerrado biome of Central Brazil

“…The wheat-growing areas identified in the present study are potential and valid only if there are no other factors restricting the development of the crop in the indicated sites and seasons. To consolidate a tropical, effectively sustainable, and competitive wheat cultivation in Brazil, it is necessary to implement changes in plant breeding and crop management by developing early-cycle wheat cultivars, improving the tolerance of cultivars both to blast disease for sowing at the beginning of February (Maciel, 2011) and to heat (Cargnin et al, 2009;Pimentel et al, 2015), and better exploring soil water availability. This can be achieved by adopting conservationist principles throughout the Cerrado biome or by taking the genetic route, using regionally adapted cultivars that better explore the deep soil profile due to the effectiveness of their root system or that have mechanisms that increase their water use efficiency (Ribeiro Jr. et al, 2006).…”