Screening for Drought Tolerance in Maize (Zea mays L.) Germplasm Using Germination and Seedling Traits under Simulated Drought Conditions

Abstract

Maize is known to be susceptible to drought stress, which negatively affects vegetative growth and biomass production, as well as the formation of reproductive organs and yield parameters. In this study, 27 responsive traits of germination (G) and seedlings growth were evaluated for 40 accessions of the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) germplasm collection, under no stress and simulated drought stress treatments by 10%, 15%, and 20% of polyethylene glycol (PEG). The three treatments significantly reduced G% and retarded seedlings growth, particularly the 15% and 20% PEG treatments; these two treatments also resulted in a significant increase of abnormal seedlings (AS). The heritability (H2) and correlations of the traits were estimated, and drought tolerance indices (DTIs) were calculated for traits and accessions. The H2 of G% values were reduced, and H2 for AS% increased as the PEG stress increased. Positive correlations were found between most trait pairs, particularly shoot and root traits, with 48 highly significant correlations under no stress and 25 highly significant correlations under the 10% PEG treatments, particularly for shoot and root traits. The medium to high heritability of shoot and root seedling traits provides a sound basis for further genetic analyses. PCA analysis clearly grouped accessions with high DTIs together and the accessions with low DTIs together, indicating that the DTI indicates the stress tolerance level of maize germplasm. However, the resemblance in DTI values does not clearly reflect the origin or taxonomic assignments to subspecies and varieties of the examined accessions.

Plant hormesis and Shelford’s tolerance law curve

“…An increase in the plant tolerance range during evolution can cause a shift of hormesis to the region of higher/lower doses relative to the optimum, as well as an increase in the width and amplitude of the hormetic zone crops (e.g., wheat, maize, rice, and soybean) is greatest during early vegetative stages and decreases progressively during flowering and early seedling stages (Djanaguiraman and Prasad 2014). Similar data was also obtained for low temperature stress (Zinn et al 2010) and drought (Badr et al 2020). In woody plants, an increase in stress resistance (and hence the width of the tolerance range) during development was found from a seedling to a mature tree (Kreuzwieser and Rennenberg 2014;Niinemets 2010).…”

“…Shelford's law of tolerance (Shelford 1931) is illustrated by a bell-shaped curve depicting the relationship between environmental factor/factors' intensity and its favorability for species or populations. It is a fundamental basis of ecology when considering the regularities of environmental impacts on living systems (Odum and Barrett 2004), and applies in plant biology (Hatfield and Prueger 2015), agriculture (Zinn et al 2010;Badr et al 2020) and forestry (Greenberg et al 2015;Tan et al 2017) to manage plant resistance to environmental limiting factors and to enhance plant productivity.…”

Ameliorative Effects of Calcium Sprays on Yield and Grain Nutritional Composition of Maize (Zea mays L.) Cultivars under Drought Stress

“…It ranks 3rd after wheat and rice in the world's production of cereal crops and is known as the king of grain crops [2,3]. Maize is valuable as a source of food, feed, oil, and biofuel [4]. Maize grains are a rich source of energy as 100 g seed provides 365 kilocalories of energy [5].…”

Multivariate analysis to determine secondary characters in selecting adaptive hybrid corn lines under drought stress

“…Corn (Zea mays L.) is one of the essential cereals in the world, which is widely used as food, feed, and bioethanol production for human and animal needs. The increase in population and the industry development will have a direct impact on increasing the corn demand (Sah et al 2020;Badr et al 2020). Efforts to increase corn production are the primary solution in reducing import quotas in Indonesia.…”

“…To generate the adaptive corn variety, many corn genotypes must be selected and grown under normal and stress condition in order to evaluate their responses to those conditions properly and effectively. This concept is widely applied by Anshori et al (2019) and Anshori et al (2020) on rice under salinity stress, Akbar et al (2019) and Farid and Ridwan (2018) on rice under drought stress, Adhikari et al (2019); Sah et al (2020) and Badr et al (2020) on corn under drought.…”