Conservação e micropropagação in vitro de variedades tradicionais locais de abacaxizeiro da Amazônia

Abstract

The genus Ananas belongs to the family Bromeliaceae and is composed of herbaceous, perennial plants typical of tropical climates. Its center of origin and genetic diversity is South America, with Brazil, Paraguay, and the Andes standing out. Local traditional pineapple varieties represent a biocultural and genetic heritage of relevance to the Amazon, but they remain vulnerable to genetic erosion due to replacement by a small number of commercial cultivars. In this context, this thesis aimed to establish and conserve, under in vitro conditions, a collection of local traditional pineapple varieties in the Amazon; to develop a micropropagation protocol for accession BAC002 (Barreirinha–AM); and to evaluate nursery seedling production strategies (containers and controlled-release fertilizer). Thirty-seven local traditional varieties were collected and established in in vitro culture; their leaf morphological characterization and dissimilarity analysis allowed the collection to be organized into distinct groups, strengthening the basis for germplasm conservation and use. As a complementary step, a micropropagation protocol was developed for a representative accession (BAC002, Barreirinha–AM), in which the etiolation phase was favored by 1.0 mg L⁻¹ 6- benzylaminopurine (BAP); shoot regeneration was maximized in a medium containing 2.0 mg L⁻¹ BAP combined with 0.25 mg L⁻¹ naphthaleneacetic acid (NAA); and rooting performed best with 0.5 mg L⁻¹ NAA, with satisfactory survival during acclimatization. In the nursery, seedling growth was driven by the interaction between substrate volume and nutritional management: polyethylene bags (0.7 L) and tubes (280 cm³; 0.25 L) produced seedlings with similar performance, and the dose of 6 g L⁻¹ Osmocote® (NPK 15-9-12, 5M) was indicated as a reference for improved growth regardless of the container, under the conditions evaluated. Leaf diagnosis using the “D” leaf indicated variation among BAG accessions, and principal component analysis showed a clear separation between tissues (leaves and roots) and gradients associated with P, K, and Mg in leaf tissue and Fe, Mn, and Cu in root tissue, with additional influence of S and Zn among treatments. In the field, vegetative performance was influenced by nursery history, with a trend for seedlings produced in tubes under higher doses to show greater growth after planting. Thus, it is concluded that integrating in vitro conservation, a micropropagation protocol, and nursery recommendations helps provide uniform seedlings and supports the conservation and sustainable use of local traditional pineapple varieties in the Amazon.