Water Use, Leaf Cooling and Carbon Assimilation Efficiency of Heat Resistant Common Beans Evaluated in Western Amazonia

Abstract

In our study, we analyzed 30years of climatological data revealing the bean production risks for Western Amazonia. Climatological profiling showed high daytime and nighttime temperatures combined with high relative humidity and low vapor pressure deficit. Our understanding of the target environment allows us to select trait combinations for reaching higher yields in Amazonian acid soils. Our research was conducted using 64 bean lines with different genetic backgrounds. In high temperatures, we identified three water use efficiency typologies in beans based on detailed data analysis on gasometric exchange. Profligate water spenders and not water conservative accessions showed leaf cooling, and effective photosynthate partitioning to seeds, and these attributes were found to be related to higher photosynthetic efficiency. Thus, water spenders and not savers were recognized as heat resistant in acid soil conditions in Western Amazonia. Genotypes such as BFS 10, SEN 52, SER 323, different SEFs (SEF 73, SEF 10, SEF 40, SEF 70), SCR 56, SMR 173, and SMN 99 presented less negative effects of heat stress on yield. These genotypes could be suitable as parental lines for improving dry seed production. The improved knowledge on water-use efficiency typologies can be used for bean crop improvement efforts as well as further studies aimed at a better understanding of the intrinsic mechanisms of heat resistance in legumes.

Physiological Characteristics of Cultivated Tepary Bean (Phaseolus acutifolius A. Gray) and Its Wild Relatives Grown at High Temperature and Acid Soil Stress Conditions in the Amazon Region of Colombia

“…For each slide reading, two random counts were made to determine the density of stomata (number mm 2 ). Likewise, the number of days to flowering (DF) and days to physiological maturity (DPM), as well as pollen viability (PV), as described by Suárez et al [ 10 , 19 , 34 ], were measured in order to determine the effects on phenological traits of different tepary accessions. The leaf temperature differential (LTD) corresponding to the difference between leaf and ambient temperature was measured using the MultispeQ handheld device [ 88 ] (Lansing, MI, USA).…”

“…For example, the Latin American region alone accounts for 40% of acidic soils worldwide, which represents a limitation for common bean cultivation [ 33 ]. In the Amazon region, the adaptation of advanced lines of common bean under acid soils with low fertility and high temperature conditions has been studied [ 10 , 19 , 34 ] to identify materials with adaptability, thus being able to improve the diet of small farmers in rural areas. However, the available germplasm collection of Phaseolus acutifolius accessions was not evaluated to identify materials that can adapt to the combined stress of high temperature and low fertility acid soils with high aluminum (Al) toxicity.…”

“…Genotypic differences among tepary bean accessions in terms of morphological, agronomic and physiological attributes were not evaluated. At the physiological level, adaptation to high temperature and acid soil stress conditions could be evaluated using chlorophyll fluorescence (Chl a ), which helps to quantify genotypic differences in using energy in response to the level of stress, particularly the energy absorbed by PSII distributed to the photochemical, heat dissipation, or unregulated pathways [ 34 ]. Thus, the objective of this study was to evaluate the differences in morpho-physiological and agronomic adaptation of cultivated tepary bean ( Phaseolus acutifolius A.…”

Chlorophyll Fluorescence Imaging as a Tool for Evaluating Disease Resistance of Common Bean Lines in the Western Amazon Region of Colombia

“…In our study, climatic conditions (high air humidity, high rainfall and high air temperature) in the Amazon region were favorable for the more frequent development of diseases. However, in the previous studies conducted by Suárez et al [ 48 , 59 , 60 ], we identified bean lines that were adapted to abiotic stress conditions at the physiological level and these lines produced grain yields that were above the Colombian average yield.…”

“…Similarly, an increase in Y(NO) was detected at the expense of a decrease in NPQ condition, as was also observed by Suárez at el. [ 48 ]. These observed changes are possibly attributable to irreversible damage in the PSII reaction centers due to the infection process, and they resulted in possible photoinhibition as reflected by low F v /F m levels [ 49 ].…”