Effect of high temperature on pollen grains and yield in economically important crops: a review

Abstract

This review explores how climate change affects plant reproductive structures and causes significant yield loss, and discusses the effect of high temperatures on pollen viability, tube length, and germination percentage. Climate change-induced extreme heat and drought increasingly threaten plant growth and development, significantly impacting sexual reproduction. Heat and drought stress can disrupt key stages of plant sexual reproduction, including flowering time, gametophyte development, pollination, and seed formation, leading to infertility and substantial yield reductions in crops. A key consequence is compromised agricultural productivity and heightened food insecurity. The productivity in terms of crop yield is reduced due to a direct correlation between phenology and climate change. The reproductive organs of a plant and other parameters that define good fertility of a species are all affected by the increasing temperatures during their vegetative and reproductive phases of growth and development. This review dissects the detrimental effects of high temperatures on pollen grain viability, germination, and morphology, directly translating to yield reductions in major crops. It underscores the critical role of pollen viability and germination studies as potential tools for identifying heat-tolerant genotypes crucial for future food security. We delve into the intricate details of high-temperature stress's impact on pollen across various developmental stages, emphasizing the paramount importance of pollen studies as a criterion for heat tolerance in economically important crops within the context of climate change.

Keywords: Brassica; Climate change; Cotton; Drought stress; Heat stress; Maize; Plant reproduction; Pollen viability; Rice; Sorghum; Soybean; Sunflower; Tomato; Wheat.