Role of Kappaphycusalvarezii seaweed extract and its active constituents, glycine betaine, choline chloride, and zeatin in the alleviation of drought stress at critical growth stages of maize crop

• Published in: Journal of applied phycology 2022-06, Vol.34 (3), p.1791-1804
• Main Authors: Trivedi, Khanjan, Anand, K G Vijay, Kubavat, Denish, Ghosh, Arup
• Format: Article
• Language: English
• Subjects: Agricultural production; Algae; Antioxidants; Biomedical and Life Sciences; Cereal crops; Chlorides; Choline; Constituents; Corn; Crop yield; Cytokinins; Drought; Ecology; Enzymes; Equivalence; Foliar applications; Freshwater & Marine Ecology; Glycine; Glycine (amino acid); Glycine betaine; Growth; Leaves; Life Sciences; Moisture effects; Moisture stress; Plant extracts; Plant growth substances; Plant Physiology; Plant Sciences; Seaweeds; Soil; Soil conditions; Soil moisture; Soil stresses; Water sprays; Zeatin
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-022-02722-1

Kappaphycus alvarezii seaweed extract (KSWE), an effective plant biostimulant, was investigated along with its active constituents, namely, glycine betaine (GB), choline chloride (Ch), and zeatin for their role in the alleviation of soil moisture stress subjected at different stages of maize crop at V5, V10, and V15 (i.e. fifth, tenth, and fifteenth leaf with fully emerged leaf collar). This study was undertaken to identify the constituents of KSWE responsible for stress alleviation under soil moisture deficit conditions. Stress was applied by withholding irrigation for 7 days at the three different growth stages of maize. Growth, yield, and antioxidant enzymes were analysed in response to four foliar treatments (viz., T1: water spray, T2: 10% equivalent concentration of zeatin as present in KSWE (Eq-cytokinin), T3: 10% KSWE, and T4: 10% equivalent concentration of GBCh as present in KSWE (Eq-GBCh). Higher yield response over control was obtained by application of Eq-GBCh or Eq-cytokinin when soil moisture stress was applied once at any of the three stages. Yield improvement was obtained only by KSWE or Eq-GBCh when plants were subjected to stress at all three stages. Application of KSWE at V5, V10, V15, and V5 + V10 + V15 stages recorded 20, 9, 18, and 32% higher grain yield over their respective controls, indicating the importance of its application at V5 and V15 stages under drought. Levels of antioxidant enzymes were also elevated under drought by KSWE when compared to its control suggesting that the stress tolerance imparting mechanism of KSWE was through the involvement of antioxidant machinery. It can be concluded from the study that cytokinin increased seed yield under moderate stress conditions, while KSWE was effective even under multiple stress.