Abscisic acid and in vitro conservation of Manihot wild species

• Published in: Acta scientiarum. Biological sciences Vol. 44; no. 1; p. 1
• Main Authors: Ferreira de Sa, Jucieny, Santos Vila Verde, Denise dos, Dhilermando Hora de Souza, Marcus, Santos Melo, Jorge Eduardo dos, Fialho dos Santos, Karen Cristina, Silva Souza, Antonio da, Cunha Alves, Alfredo Augusto, Silva Ledo, Carlos Alberto da
• Format: Journal Article
• Language: English; Portuguese
• Published: Maringa Universidade Estadual de Maringa 01-01-2022; Editora da Universidade Estadual de Maringá - EDUEM; Universidade Estadual de Maringá
• Subjects: Abscisic acid; Abscission; Conservation; Dormancy; Germplasm; growth inhibitor; plant genetic improvement; in vitro germplasm; Manihot; Shoots; Species; Tissue culture; República del Congo; América Latina
• ISSN: 1679-9283; 1807-863X
• DOI: 10.4025/actascibiolsci.v44i1.59549

Abscisic acid (ABA) is associated with bud dormancy, leaf abscission, and germplasm growth inhibition in in vitro conservation. We evaluated the effects of ABA in four wild Manihot accessions and one cassava accession (M. esculenta Crantz) to refine in vitro conservation methods for these species. The experiment was performed at the Laboratory for Tissue Culture from Embrapa, Cruz das Almas, Bahia State, Brazil. The statistical design was completely random in a 5 × 5 factorial scheme [(5 ABA dosages (0, 0.25, 0.50, 0.75, and 1 mg L-1) and 5 Manihot species (M. pseudoglaziovii, M. tristis, M. flabellifolia, M. chlorosticta, and M. esculenta)], with 15 replicates. Mini-cuttings of 1 cm were used, each inoculated in 10 mL of modified Murashige and Skoog medium, solidified with Phytagel® (2.4 g L-1) containing the respective ABA dosages. Tubes containing these mini-cuttings were placed in a germplasm conservation room with an irradiance of 30 µmol m-2 s-1, temperature of 22 ± 1°C, and photoperiod of 12 hours. Plant height (cm), the number of living and senescent leaves, shoots, and mini-cuttings (1 cm), and fresh and dry weights of shoots and roots (mg) were evaluated after 150 days. Growth reduction was prominent in M. pseudoglaziovii, M. tristis, and M. flabellifolia during the in vitro conservation period. In the present study, the addition of ABA did not promote the expected reduction in plant growth