Water-deficit tolerance of landrace and improved corn genotypes

Abstract

The objective of this work was to evaluate the yield, leaf area, stomatal conductance, photosynthesis, transpiration, and critical fraction of transpirable soil water (FTSWc) of hybrid and landrace corn (Zea mays) genotypes, as affected by the water deficit characterized by the FTSW. Two experiments were carried out in the 2015/2016 and 2016/2017 crop years: one in the field and the other in a greenhouse. The following genotypes were evaluated in irrigated and nonirrigated systems: the Cinquentinha and Bico de Ouro landraces and the AS 1573PRO improved cultivar. Yield in the field was higher for 'AS 1573PRO', followed by Bico de Ouro and Cinquentinha in both evaluation years. Water deficit reduces stomatal opening, photosynthesis, and transpiration rate, resulting in the total closure of the stomata of 'AS 1573PRO' and Bico de Ouro, and in the partial closure of those of Cinquentinha. There was a reduction in the leaf area of 'AS 1573PRO', Bico de Ouro, and Cinquentinha under water deficit during the reproductive period. In the first crop year under water deficit conditions, 'AS 1573PRO' and Cinquentinha show a high tolerance to water deficit with a FTSWc of 0.71, and 'AS 1573PRO' also shows the highest tolerance in the second crop year with a FTSWc of 0.73. Moreover, Bico de Ouro is sensitive to water deficit in the two crop years.

Drought Resilience in Oil Palm Cultivars: A Multidimensional Analysis of Diagnostic Variables

“…Different studies [19][20][21] indicate that cultivars with the least negative leaf water potential, when subjected to a water deficit, are potentially more tolerant to stressful events. Similar conclusions have been found in other monocots, such as sugarcane [28], wheat [24], and corn [29], and dicotyledons, such as cotton [30] and potato [31].…”

Mitigating soil water deficit using organic waste compost and commercial water retainer: a comparative study under semiarid conditions

“…Under water stress, various LRWC levels have been reported for maize because these studies have been conducted under different pedoclimatic conditions and using different cultivars. Selection programs for cultivars may reflect the capacity for more efficient water uptake from moisture-deficient soils or the ability of stomata to reduce water loss for water conservation (Zhang et al 2018;Langner et al 2021). The maintenance of a higher LRWC ensures better hydration as shown in the study of Langner et al (2021) who noticed more favorable water relations in internal tissues and better capacity for tolerance to drought in resistant plants.…”

“…Selection programs for cultivars may reflect the capacity for more efficient water uptake from moisture-deficient soils or the ability of stomata to reduce water loss for water conservation (Zhang et al 2018;Langner et al 2021). The maintenance of a higher LRWC ensures better hydration as shown in the study of Langner et al (2021) who noticed more favorable water relations in internal tissues and better capacity for tolerance to drought in resistant plants. As presented in Table 5, all addressed agromorphological properties were highly correlated to LRWC, showing significant Pearson product-moment correlation coefficients varying between 1.00 ± 0.27 a 8.0 ± 0.47 a 59.0 ± 5.6 a 27.6 ± 6.7 a 31.0 ± 5.6 a 9.6 ± 4.2 a 43.6 ± 14.8 a D-WS 56 ± 4.5 a 1195 ± 204 a 1.33 ± 0.27 a 9.6 ± 0.47 a 64.6 ± 5.6 ab 33.3 ± 6.7 a 32.6 ± 5.6 a 8.6 ± 4.2 a 68.8 ± 14.8 ab D-DS 62 ± 5.8 a 1476 ± 204 a 1.33 ± 0.27 a 10.0 ± 0.47 ab 78.3 ± 5.6 bc 45.0 ± 6.7 ab 41.0 ± 5.6 a 9.5 ± 4.2 a 69.0 ± 14.8 ab 0.82 and 0.97.…”

“…The decrease in total biomass, leaf area, and shoot/ root biomass ratio as well as their physiological changes can be associated with their drought hardening (Song et al 2019). The structural adjustment in leaf area would imply an effective way to limit water loss, and the greater allocation to roots would inevitably improve water uptake, allowing a more favorable plant water balance and gas exchange capacity under drought (AbdAllah et al 2021;Langner et al 2021). Under deficit irrigation, organic waste compost application significantly improved most of plant parameters with respect to the commercial water absorbent and eventually the untreated soil (Table 4).…”