Determining critical pre‐ and post‐anthesis periods and physiological processes in Lycopersicon esculentum Mill. exposed to moderately elevated temperatures

Abstract

To determine the thermosensitive periods and physiological processes in tomato flowers exposed to moderately elevated temperatures, tomato plants (Lycopersicon esculentum Mill., cv. NC 8288) were grown at 28/22 degrees C or 32/26 degrees C day/night temperature regimes and then transferred to the opposite regime for 0-15 d before or 0-24 h after anthesis. For plants initially grown at 28/22 degrees C, moderate temperature stress before anthesis decreased the percentage of fruit set per plant, but did not clarify the thermosensitive period. The same level of stress did not significantly reduce fruit set when applied immediately after anthesis. For plants initially grown at 32/26 degrees C, fruit set was completely prevented unless a relief period of more than 5 d was provided before anthesis. The same level of stress relief for 3-24 h after anthesis also increased fruit set. Plants were most sensitive to 32/26 degrees C temperatures 7-15 d before anthesis. Microscopic investigation of anthers in plants grown continuously at high temperature indicated disruption of development in the pollen, endothecium, epidermis, and stomium. This disruption was reduced, but still observable in plants relieved from high temperature for 10 d before anthesis.

Sensitivity of flowering plant gametophytes to temperature fluctuations

“…Jagadish et al, 2007;Mamun et al, 2006;Prasad et al, 2006), relating chilling and heat stress during booting (early gametophyte development) and flowering to higher spikelet sterility. Similarly, the effect of high temperatures during flowering in tomato (Solanum lycopersicum L.) has also been studied in detail, and not only extreme high temperatures, but even a mild increase in temperature during a short spell coincident with some flowering stages have been shown to affect negatively fruit set Page 6 of 24 A c c e p t e d M a n u s c r i p t 6 (Abdulbaki and Stommel, 1995;Sato et al, 2002). Bell pepper (Capsicum annum L.) has been reported to be equally sensitive to high temperature stress during flowering (Erickson and Markhart, 2002).…”

“…Tapetum -the innermost layer of the anther wall-hypertrophy in rice (Nishiyama, 1984) and its earlier degeneration in many other species (Ahmed et al, 1992;Erickson and Markhart, 2002;Porch and Jahn, 2001), which deprives developing pollen grains from essential nutrients and metabolites, is another symptom frequently reported as accompanying pollen sterility under low and high temperature stresses. However, development of the external layers of the anther wall, such as epidermis, endothecium, stomium and septum, has also been shown to be disrupted (Ahmed et al, 1992;Matsui and Omasa, 2002;Porch and Jahn, 2001;Sato et al, 2002), finally affecting anther dehiscence and leading to male sterility even though the pollen is viable. Major alterations in gene expression under high temperature stress have been shown, paralleling tapetum degeneration and pollen sterility, in barley (Hordeum vulgare L.) (Abiko et al, 2005) and rice (Endo et al, 2009).…”

“…A c c e p t e d M a n u s c r i p t 9 turnover in developing pollen grains, and, hence, lower accumulation of soluble carbohydrates (Aloni et al, 1991;Jain et al, 2007;Oliver et al, 2005;Pressman et al, 2002;Sato et al, 2002). A complete understanding of temperature stress on pollen development must await further understanding of carbohydrate turnover during this phase.…”

Analysis of self-fertilization and meiotic behavior of eleven Brazilian triticale cultivars at two sowing dates

“…The differences observed in this study with respect to sowing date are consistent with the work of Sisodia and Mcginnis (1970), D Guerra et al who found varying levels of meiotic instability in triticale genotypes sown at different dates. According to Sato et al (2002), in many species the reproductive stage is more sensitive to abiotic stresses than the vegetative stage. Saini et al (1997) considered the meiotic stage as the most sensitive period in the life cycle of seed plants.…”

Genome-Wide Association Mapping of Fertility Reduction upon Heat Stress Reveals Developmental Stage-Specific QTLs in Arabidopsis thaliana

“…Besides maize, many other cereals, such as wheat (Triticum aestivum), barley (Hordeum vulgare), and rice (Oryza sativa), are affected by high temperatures during the reproductive phase (Barnabás et al, 2008). Negative effects of heat stress have also been reported for other important crops from various plant families, such as tomato (Solanum lycopersicum) (Sato et al, 2002(Sato et al, , 2006 and pepper (Capsicum annuum) (Marcelis et al, 2004) from the Solanaceae family, canola and mustard (Brassica juncea, Brassica rapa, and Brassica napus) (Angadi et al, 2000;Gan et al, 2004) from the Brassicaceae family, soybean (Glycine max) (Djanaguiraman et al, 2013) and chickpea (Cicer arietinum) (Clarke and Siddique, 2004) from the Fabiaceae family, and peach (Prunus persica) (Hedhly et al, 2005) and cherry (Prunus avium) (Hedhly et al, 2004) from the Rosaceae family. Thus, heat stress is an important factor that affects crop yields worldwide.…”