Abstract Potato plants are often subjected to heat stress during growth and development, resulting in loss of yield and quality. However, the possibility exists that commercially important genotypes show tolerance to heat stress. In this study, we aim to investigate the morphological and physiological effects of moderate conditions of heat stress on tuberization in nine potato genotypes, and how it affects propagation using an ex vitro and in vitro system. The plant material came from the In Vitro Germplasm Bank of the International Potato Center (CIP). The incubation temperatures of the cultures in in vitro and ex vitro conditions were the ambient in the laboratory and greenhouse, respectively. In in vitro system a randomized complete block design was employed in nine genotypes, two treatments: multiplication culture medium and the same culture medium supplemented with 8.0% sucrose and 500 mg/L-1 CCC, six flasks and five explants per experimental unit. Among all genotypes evaluated, Leona and Liberteña did not form tubers under ex vitro treatment conditions. Under in vitro conditions, Amarilis, Capiro, Perricholi and Tacna showed no evidence of tuberization, and Canchán was the only genotype where 100% formation of tuberous structures were produced in all evaluations. The findings concluded in this study showed that of all the potatoes evaluated, Canchán best responded to the evaluations under both in ex vitro and in vitro conditions, at maximum temperatures between 22.4 to 26.9 and 27.0 to 28.2 oC, respectively. Therefore, it is vitally important to consider its development potential in different producing locations around the world, which are directly and indirectly affected by climate change.

Resumen Ficus americana y F. obtusifolia, se encuentran entre las especies arbóreas más importantes de los Bosques Tropicales Estacionalmente Secos (BTES) por su condición de siempre verdes y sus altos niveles de biomasa. Sin embargo, el BTES de Lambayeque y el norte de Perú está disminuyendo enormemente debido al avance de la agricultura migratoria, la minería ilegal y la deforestación. El objetivo de este trabajo fue estudiar los aspectos taxonómicos de ambas especies, así como la germinación de semillas, la micropropagación y la conservación de germoplasma in vitro. La germinación de semillas fue de 100 % en ambas especies hasta tres meses después de la recolección. Respecto a la micropropagación, el enraizamiento y la conservación de germoplasma, el medio de cultivo de Piper resultó efectivo, el cual está conformado por sales minerales MS con IAA 0.02 mg.L-1 y GA3 0.02 mg.L-1. La conservación in vitro de germoplasma duró más de 24 meses en ambas especies. La aclimatación en condiciones de invernadero alcanzó 50 % de supervivencia en ambas especies.

Abstract Ficus americana and F. obtusifolia are among the most important tree species in Seasonally Dry Tropical Forests (SDTF) due to their evergreen condition and high levels of biomass. However, the SDTF of Lambayeque and northern Peru is greatly diminishing due to the advance of migratory agriculture, illegal mining, and deforestation. The objective of this work was to study the taxonomic aspects of both species, as well as seed germination, micropropagation, and in vitro germplasm conservation. Seed germination was 100% for both species up to three months after collection. As for micropropagation, rooting, and germplasm conservation, the Piper culture medium was effective, as it was constituted by MS mineral salts with 0.02 mg.L-1 IAA and 0.02 mg.L-1 GA3. In vitro germplasm conservation lasted more than 24 months for both species. Acclimatization under greenhouse conditions reached 50% survival for both species.

SUMMARY Indiscriminate deforestation is one of the anthropic activities that most impacts global biodiversity. Its immediate effects mainly reach vulnerable species with high commercial value, such as Cedrela odorata, so the development of biotechnological studies is a crucial element for the genetic conservation of its populations. In this context, this work aimed to analyze the seed germination, micropropagation, and germplasm conservation of C. odorata in one of the most arid regions in northern Peru. Seed germination reached 76.6 % development, with germination time between 9 and 12 days. Likewise, micropropagation produced seedlings with stem tips up to 5.4 cm in height, 12 nodes, and 83 % rooting. Finally, the conservation of germplasm resulted in individuals that reached up to 12 cm in height, 19 nodes, and presented an optimal root system. The positive results regarding seed germination, micropropagation, and germplasm conservation of C. odorata in northern Peru could offer new approaches to the development and genetic conservation of its populations, and provide a more efficient alternative for the management and local conservation of the species.

RESUMEN La deforestación indiscriminada es una de las actividades antrópicas que más impactan la biodiversidad global. Sus efectos inmediatos alcanzan principalmente especies vulnerables y con alto valor comercial, como Cedrela odorata, por lo que el desarrollo de estudios biotecnológicos es un elemento crucial para la conservación genética de sus poblaciones. En ese contexto, el objetivo de este trabajo fue analizar la germinación de semillas, micropropagación y conservación de germoplasma de C. odorata, en una de las regiones más áridas del norte del Perú. La germinación de semillas alcanzó una eficiencia de 76,6 %, con velocidades de germinación de entre 9 y 12 días. Asimismo, en ensayos de micropropagación se obtuvieron plántulas con ápices caulinares de hasta 5,4 cm de altura, 12 nudos y 83 % de eficiencia de enraizamiento. Por último, la conservación de germoplasma resultó en individuos que, a los 30 meses de cultivo, alcanzaron hasta 12 cm de altura, 19 nudos y presentaron un óptimo sistema radicular. Este estudio sugiere que los efectos positivos sobre la germinación de semillas, micropropagación y conservación de germoplasma de C. odorata en el norte del Perú, podrían ofrecer nuevos enfoques sobre el desarrollo y conservación genética de sus poblaciones, funcionando incluso como una alternativa más eficiente para el manejo y conservación local de la especie.

RESUMO A fragmentação de habitats é uma das principais causas da criação de bordas e seus efeitos. Características funcionais das árvores, como a densidade da madeira, altura e diâmetro, são variáveis essenciais que permitem inferir vários processos ecológicos. Este estudo avaliou a variabilidade das características funcionais das árvores em dois tipos de habitats (borda e interior) de um remanescente florestal. Foram testadas as hipóteses de que i) as características funcionais teriam menores valores nas bordas do que no interior, e que ii) as variáveis ambientais influenciam essas diferenças. Este estudo foi realizado no maior remanescente de Mata Atlântica dentro do Parque Estadual da Serra da Tiririca, Brasil, estabelecendo dez parcelas (50 × 20 m) entre diferentes habitats. Dentro de cada parcela foram retiradas amostras de madeira de todas as árvores com diâmetro ≥ 10 cm. Além disso, foram registradas a altitude, distância das parcelas até a borda e registros de queimadas como possíveis variáveis explicativas (variáveis ambientais). A densidade da madeira foi obtida através do método de imersão. Para verificar diferenças nas características funcionais por tipo de habitat, foi aplicado o teste de Wilcoxon. Adicionalmente, foi avaliada a influência das variáveis explicativas sobre as características funcionais por meio de modelos lineares generalizados. Cento e oitenta e cinco árvores foram registradas nas bordas e 218 árvores no interior do remanescente. A densidade da madeira e a altura das árvores foram significativamente menores nas bordas do que no interior. Além disso, os melhores modelos indicaram relações significativas entre densidade da madeira e o tipo de habitat; assim como, entre o diâmetro e distância até a borda. Este estudo foi eficaz em abordar variáveis adequadas para prever os efeitos de borda no remanescente.

ABSTRACT Habitat fragmentation is one of the leading causes of edge genesis and its effects. Functional tree traits such as wood density, height, and diameter are essential variables from which it is possible to infer several ecological processes. This study assessed the variability of the functional traits of trees over two habitats (edge and interior) of a forest remnant. The hypothesis tested were i) the functional traits would have lower values at the edges than the interior, and ii) environmental variables would influence such differences. This study was carried out in the largest Atlantic Forest remnant within Serra da Tiririca State Park, Brazil, by establishing ten plots (50 × 20 m) among different habitats. Within each plot, wood samples were taken from all trees with a diameter of ≥ 10 cm. It was recorded the altitude, distance from the plots to the edge, and fire records as possible explanatory variables (environmental variables). Wood density was obtained using the immersion method. To verify differences in functional traits by habitat, the Wilcoxon test was applied. Additionally, the influence of explanatory variables on functional traits through generalized linear models was evaluated. One hundred eighty-five trees were recorded at the edges and 218 trees at the interior of the remnant. Wood density and tree height were significantly lower in the edges than in the interior. Furthermore, the best models indicated significant relationships between wood density and habitats, as well as diameter and distance to the edge. This study was effective in raising suitable variables to predict edge effects.