Tolerance to mid‐season drought in peanut can be achieved by high water use efficiency or high efficient use of water

Abstract

Peanut (Arachis Hypogaea L) is an economic cash crop mainly planted in arid and semi-arid regions where drought causes approximately 20% yield losses every year.It has been demonstrated that drought tolerance can be achieved by two different mechanisms in plants: either by saving water or by extracting more water from the soil (water spender genotypes). The objective of this research was to screen for these two mechanisms of drought tolerance in peanut. Plants were grown in rainout shelters under irrigated conditions until mid-pod filling, then drought was induced using rainout shelters. Gas exchange parameters were measured regularly during the drought period and recovery. Genotypes PI 502120 and AU-NPL 17 were classified as water spender genotypes as they showed high yield, Δ 13 C, photosynthesis, and stomatal conductance under drought. This is the first time that water spender genotypes have been identified in peanut. On the other hand, genotypes Line-8 and AU16-28 were classified as water savers as they showed equally high yields but with low Δ 13 C and stomatal conductance and moderate photosynthesis under drought stress. In this study, water spender genotypes did not show a yield advantage in comparison with water savers. INTRODUCTIONPeanut (Arachis Hypogaea L) is an important oilseed and human staple food crop as peanut seed contains 38-56% oil, 28-33% protein, 20% carbohydrates, and enriched vitamins and minerals (Food Data Central, 2019). In the Southeastern United States, peanut is used as a summer rotation crop with cotton to prevent boll weevil development in cotton (Johnson et al., 2001). In 2020, 3 million metric tonnes were produced in the United States on 526,000 ha (USDA, 2020), most of which are planted in Georgia,

Sustaining yield and nutritional quality of peanuts in harsh environments: Physiological and molecular basis of drought and heat stress tolerance

“…Reduced leaf area expansion and lower photosynthesis per leaf area lead to a decline in canopy carbon assimilation that will reduce biomass accumulation and yield ( Reddy et al, 2003 ). Plant traits that preserve soil moisture, such as high-water use efficiency (WUE) due to rapid stomatal closure, could increase drought tolerance ( Devi et al, 2010 ; Devi and Sinclair, 2011 ; Shekoofa et al, 2015 ; Sinclair et al, 2017 ; Zhang et al, 2022 ). Contrarily, there are peanut cultivars that can maintain adequate plant water status and escape drought by collecting more water due to a more complex or deep root system ( Rowland et al, 2012a ; b ; Zhang, et al, 2022 ).…”

“…Plant traits that preserve soil moisture, such as high-water use efficiency (WUE) due to rapid stomatal closure, could increase drought tolerance ( Devi et al, 2010 ; Devi and Sinclair, 2011 ; Shekoofa et al, 2015 ; Sinclair et al, 2017 ; Zhang et al, 2022 ). Contrarily, there are peanut cultivars that can maintain adequate plant water status and escape drought by collecting more water due to a more complex or deep root system ( Rowland et al, 2012a ; b ; Zhang, et al, 2022 ). Utilization of genomic and genetic resources for developing peanuts for harsh environment conditions are illustrated in Figure 1 .…”

“…Drought-tolerant peanut cultivars can exhibit high WUE or EUW. Peanut cultivars with high EUW do not show a yield advantage compared to high WUE under mid-season drought ( Zhang et al, 2022 ). The high EUW capacity of these peanut cultivars has not yet been associated with a more profound or complex root system, as evidenced in the common bean ( White et al, 1990 ).…”

“…Several such sets are reported for efficient utilization of genetic resources in peanut breeding and genetics ( Ding et al, 2022 ; Dwivedi et al, 2008 ; Holbrook and Stalker, 2003 ; Holbrook and Dong, 2005 ; Upadhyaya et al, 2002a and; 2002b ). The U.S. peanut mini-core collection has been effectively used for the identification of interesting alleles and traits for breeding programs for traits related to drought tolerance ( Wang H, et al, 2016 ; Wang M. L. et al, 2016 ; Zhang et al, 2019 ; Li et al, 2022 ; Patel et al, 2022 ; Zhang et al, 2022 ). End-of-season drought tolerance was reported in 15 accessions after evaluating ICRISAT peanut mini core collection and selected based on pod yield, SPAD, and SLA measurements ( Upadhyaya, 2005 ).…”

“…In addition, gas exchange parameters were measured regularly during the drought and recovery to monitor dynamic changes in photosynthesis and g s under stress. Genotypes with high yield, Δ 13 C, photosynthesis, and g s under stress were classified as water spenders while genotypes with equally high yields but with low Δ 13 C and g s and moderate photosynthesis under drought stress were classified as water savers ( Zhang et al, 2022 ). The previous reports on screening US peanut mini core collection across three irrigation treatments over 2 years and two field locations unfolded five accessions (PI 502120, PI 493329, Line 8, Georgia-06G, AU-NPL-17) as resistant to drought.…”