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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Genetics Research » Research » Publications at this Location » Publication #416396
Research Project: Characterization and Introgression of Nematode Resistance into Upland Cotton

Location: Crop Genetics Research

Title: Does warmer nighttime affect the carbon balance in soybeans?

Author
item SANKARAPILLAI, LEKSHMY - Mississippi State University
item ADHIKARI, BIKASH - Mississippi State University
item Stetina, Salliana - Sally
item REDDY, K. RAJA - Mississippi State University
item BHEEMANAHALLI, RAJU - Mississippi State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/30/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Soybean is the fourth most important commodity crop globally but is sensitive to temperature variations during the reproductive and pod-filling stages. Increasing maximum (day) and minimum (night) temperatures negatively influence crop yield. Historical weather data analysis suggested that night temperatures in the southeastern US region were approximately twice the rate of day temperatures. However, limited studies quantified the tolerance and sensitivity of soybeans to high night temperatures (HNT) during grain filling. Thus, this study quantified the impact of HNT on photosynthesis and respiration and their relationship with yield components. Seventeen soybean genotypes were exposed to control (23±2.3') and HNT (27.8±0.6') with a consistent daytime temperature of 32' from R2 until physiological maturity. A 4.8' increase in nighttime temperature resulted in a 17% reduction in photosynthetic rate (A) and a 29% increase in nighttime respiration rate (Rd). Among the diurnal and nocturnal gas exchange parameters, nocturnal stomatal conductance was decreased by 54%, followed by a 38% decrease in nocturnal transpiration. On average, a 1°C rise in nocturnal temperature resulted in a 2.8% reduction in yield. The efficiency of assimilate utilization showed a stronger negative association with seed yield under HNT. Genotypes with higher tolerance to HNT maintained assimilate utilization efficiency (Rd/A), and higher yields. Our findings emphasize the importance of developing soybean varieties with HNT tolerance to sustain yields under warmer climatic conditions.