Traits Related to Heat Stress in Phaseolus Species

Abstract

Traits related to heat stress in bean species (Phaseolus spp.) have been insufficiently explored to date, yet studies of these traits are needed given that heat stress is predicted to become more frequent and severe in many parts of the world because of climate change. In order to detect agro-morphological and physiological traits related to heat stress and selection for resistance to heat stress, a total of 196 bean genotypes including eight genotypes of tepary bean (P. acutifolius L.), five genotypes of scarlet runner bean (P. coccineus A. Gray), two genotypes of year bean (P. dumosus Macfady), five genotypes of lima bean (P. lunatus L.), and 176 genotypes of common bean (P. vulgaris L.) were evaluated in 2019 and 2020 under moderate (field) and extreme heat stress (greenhouse) conditions. Although most genotypes of P. acutifolius, P. lunatus, and P. coccineus were found to be more resistant to heat stress than most genotypes of common bean, some genotypes of common bean were shown to perform as well as P. acutifolius, P. lunatus, and P. coccineus. Biomass among agronomical traits had the highest significant direct effects on the resistance to heat stress score. The maximum quantum efficiency of PSII and SPAD values among physiological traits showed significant direct effects on the resistance to heat stress score. Biomass, leaflet size, the SPAD value and maximum quantum efficiency of PSII can be considered as heat stress-related traits, and, P. acutifolius, P. lunatus, P. coccineus, and some genotypes of P. vulgaris can be considered for exploitation in a heat stress tolerance breeding program.

Deciphering the Enhancing Impact of Exogenous Brassinolide on Physiological Indices of Melon Plants under Downy Mildew-Induced Stress

“…The chlorophyll fluorescence parameter is an important measurement to determine specific photosynthetic indices under stress conditions [ 68 , 69 , 70 , 71 ]. The F0 value is the least fluorescence that denotes the basis of the photosystem II (PSII) reaction system [ 72 , 73 ]. Our current findings depicted that the F0 values in melon seedling leaves decreased at 48 h post-infection, while the samples treated with BR showed higher F0 values compared to the CK group ( Table 2 ), indicating that downy mildew might directly damage the PSII system during the disease period and that activation of the PSII reaction center towards light was diminished in melon leaves.…”

Influence of Increase in Phosphorus Supply on Agronomic, Phenological, and Physiological Performance of Two Common Bean Breeding Lines Grown in Acidic Soil under High Temperature Stress Conditions

“…These changes induce stomatal closure that limits CO 2 diffusion from the stomata through intercellular spaces and carboxylation sites throughout the leaf mesophyll cells [ 29 ]. However, some plants develop several adaptive mechanisms to cope with heat stress [ 30 ], such as the production of heat shock proteins, to protect cellular components from damage caused by high temperatures [ 28 , 31 ].…”

“…These changes often result in decreased bean productivity due to a reduction in carbon assimilation and biomass accumulation [10,23,26]; affecting flower production, pollen viability, and pod formation; and decreasing the seed number, seed size, and seed yield [21,23,27]. Similarly, at higher temperatures (35)(36)(37)(38)(39)(40)(41)(42) • C), several physiological processes are affected, disrupting the biochemical reactions of photosynthesis, including the functioning of chloroplasts and enzymes [28]. These changes induce stomatal closure that limits CO 2 diffusion from the stomata through intercellular spaces and carboxylation sites throughout the leaf mesophyll cells [29].…”