Genetic parameters of drought tolerance in cacao germplasm under field and greenhouse conditions

• Published in: Euphytica Vol. 220; no. 7; p. 103
• Main Authors: Carvalho, Mariana Rocha de, Lopes, Uilson Vanderlei, Oliveira, Bruna Santos, Novaes, Danilo Sampaio, Valle, Raúl René Meléndez
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2024; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biotechnology; Breeding; Cloning; Cocoa; Dehydration; Drought resistance; Dry season; Germplasm; Global climate; Greenhouses; Heritability; Life Sciences; Moisture content; Parameter identification; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Plant species; Seedlings; Soil water; Survival; Water content; Indirect selection; Genetic variability; Breeding approach; Drought tolerance; Cacao
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-024-03359-6

Cacao is a tropical tree species, is highly sensitive to soil water limitations, and its production is strongly affected by global climatic fluctuations. The study of variability in cacao germplasms offers insights into identifying morphological traits associated with drought tolerance. Assessing the genetic parameters of these traits is essential to optimize selection strategies in breeding programs. This study estimated genetic parameters for eighteen cacao progenies and seven parental clones in the field and in greenhouse conditions. The family heritability (h 2 fam ) and individual heritability (h 2 ind ) of pod production during the dry season were calculated as h 2 fam  = 0.30 and h 2 ind  = 0.27. Regarding relative water content (RWC), the highest h 2 fam value was observed after 180 min of dehydration (0.26). High genetic values were observed for the parental clones CEPEC-2002 and SJ-02, as well as their progenies, in terms of production and RWC in the field. The survival and RWC of greenhouse seedlings were correlated with the evaluations carried out in adult plants in the field (a maximum r of 0.49*** between RWC in the field and survival in the greenhouse and a maximum r of 0.66*** between RWC in both conditions). These findings provide valuable insights to enhance breeding strategies to improve cacao drought tolerance.