Assessing the Heat Tolerance of Meiosis in Spanish Landraces of Tetraploid Wheat Triticum turgidum

Abstract

Heat stress alters the number and distribution of meiotic crossovers in wild and cultivated plant species. Hence, global warming may have a negative impact on meiosis, fertility, and crop productions. Assessment of germplasm collections to identify heat-tolerant genotypes is a priority for future crop improvement. Durum wheat, Triticum turgidum, is an important cultivated cereal worldwide and given the genetic diversity of the durum wheat Spanish landraces core collection, we decided to analyse the heat stress effect on chiasma formation in a sample of 16 landraces of T. turgidum ssp. turgidum and T. turgidum ssp. durum, from localities with variable climate conditions. Plants of each landrace were grown at 18–22 °C and at 30 °C during the premeiotic temperature-sensitive stage. The number of chiasmata was not affected by heat stress in three genotypes, but decreased by 0.3–2 chiasmata in ten genotypes and more than two chiasmata in the remaining three ones. Both thermotolerant and temperature-sensitive genotypes were found in the two subspecies, and in some of the agroecological zones studied, which supports that genotypes conferring a heat tolerant meiotic phenotype are not dependent on subspecies or geographical origin. Implications of heat adaptive genotypes in future research and breeding are discussed.

Genetic approaches to exploit landraces for improvement of Triticum turgidum ssp. durum in the age of climate change

“…Therefore, landraces from this region potentially include adaptive traits that could be exploited to boost the breeding for heat/drought tolerance and promote cultivars adaptation to stress-prone environments. Up to now, drought, heat, and salinity resistance traits have been studied in landraces coming from the Mediterranean basin, such as in Jordanian, Israeli-Palestinian, Tunisian, Italian, and Spanish, but also Afghan landraces (Al Khateeb et al, 2017;Shamaya et al, 2017;Hamdi et al, 2020;Frankin et al, 2021;Naranjo et al, 2022;Taranto et al, 2022). However, works concerning the mapping analysis of resistance traits to abiotic stresses are less in number than the biotic stresses ones.…”

OsGRF4AA compromises heat tolerance of developing pollen grains in rice

“…Developing pollen grains are more vulnerable to high temperatures than cells from other plant tissues. High temperatures cause production loss directly by decreasing pollen grain viability and seed formation in crops (Draeger and Moore, 2017;Peng et al, 2020;Bokshi et al, 2021;Naranjo et al, 2022). As a key modulator of HS response, heat stress transcription factor A2 (HSFA2) plays an essential role in the thermotolerance of meiocytes and microspores in plants (Frank et al, 2009;Akerfelt et al, 2010;Vihervaara et al, 2013;Fragkostefanakis et al, 2016).…”