Catriane Sousa-Santos

Damage to the photosynthetic apparatus during leaf dehydration is an indicator of the maintenance of leaf vitality and the resilience of tree seedlings to severe drought. Genipa americana is a tree widely distributed in the neotropical region but with great ecological and sociocultural importance in the south of the state of Bahia, Brazil, where its fruits are harvested from subspontaneous trees. This study aimed to compare the feasibility of the maximum quantum efficiency of photosystem II (Fv/Fm) and performance indexes derived from the JIP test, i.e., performance index on absorption basis (PI_abs) and total performance index (PI_total), for screening G. americana seedlings from different mother plants for leaf damage caused by dehydration. From leaf dehydration curves, we calculated the values of relative water content (RWC) in which Fv/Fm, PI_abs, and PI_total reach a loss of 10% and 50% in relation to the values of fully hydrated leaves. PI_total was the only parameter that revealed consistent significant differences between progenies for RWC at 50% of percentage loss. Significant differences were observed among progenies for leaf traits; however, no correlation was detected between these traits and chlorophyll fluorescence parameters. Monitoring the PI_total values during leaf dehydration is a useful tool for screening G. americana progenies in relation to their capacity to maintain leaf vitality under occasional severe droughts.

Genipa americana (Rubiaceae) is a fruit tree with broad phytogeographic domain and suitable for different silvicultural systems in the tropics. The knowledge associated with the relative growth rate of species such as G. americana, provides important guidelines for the effective establishment and survival of seedlings after planting in the field. In this study we investigated differences in growth, biomass allocation and photosynthesis of seedlings originating from different mother plants of G. americana in southern Bahia, Brazil. For this, we evaluated fifteen variables associated with carbon balance at the whole plant and leaf scales of twelve G. americana progenies. All seedlings grew over a period of 198 days under similar microclimatic conditions with approximately 65% full sun. Our results showed significant differences in the relative growth rates (RGR), with the highest and lowest mean values being 29.0 and 38.0 mg g^-1 day^-1, respectively. Differences in RGR between G. americana progenies were highly related to differences in biomass allocation at both whole plant and leaf scales. From a practical point of view, we demonstrate that the selection of mother plants to produce seedlings with higher growth rates, and consequently greater establishment capacity in field plantings, can be made from evaluations of growth and biomass allocation variables at the whole plant scale.

Resumo: As palmeiras (Arecaceae) exercem grande relevância na estrutura e funcionamento dos ecossistemas de florestas tropicais, além de compreenderem recursos‐chave para animais frugívoros. Entretanto, muitas espécies estão atualmente em risco de extinção devido à superexploração e/ou perda de habitat. Nosso estudo visou realizar uma revisão sistemática com uma abordagem cientométrica de todas as 78 espécies de palmeiras nativas da Mata Atlântica brasileira, buscando identificar as espécies e regiões mais bem estudadas, principais tópicos estudados, padrões gerais, tendências e lacunas na pesquisa científica associada a esta família botânica. No total, foram realizados estudos para 48 espécies pertencentes a 10 gêneros, com o número de estudos aumentando exponencialmente a partir dos anos 70 e exibindo grande diferença no número de publicações entre as espécies. Euterpe edulis foi a espécie mais estudada (n = 274), seguida por Acrocomia aculeata (n = 205), enquanto Bactris bahiensis (1), Geonoma litoralis (1), Syagrus santosii (1) e Trithrinax acanthocoma (0) foram as espécies menos estudadas. O maior número de estudos foi realizado nos estados do sudeste do Brasil. Com relação ao tipo de estudos, 34% e 27% estavam relacionados a propriedades bioquímicas e processos ecológicos, respectivamente, enquanto os estudos sobre entomologia (n = 26), cultura de tecidos (n = 23) e taxonomia (n = 7) representaram o menor número. Dado o papel fundamental das palmeiras nas florestas tropicais, nosso estudo sugere que as pesquisas futuras devem se concentrar em espécies menos estudadas, incluindo Desmoncus spp., Geonoma spp. e Trithrinax sp. e em algumas áreas menos estudadas, como a porção nordeste da Mata Atlântica.

Palms (Arecaceae) exert great relevance to the structure and functioning of tropical forest ecosystems, in addition to comprise key resources for frugivorous animals. However, many species are currently at risk of extinction due to overexploitation and/or habitat loss. Our study aimed to perform a systematic review with a scientometric approach of all 78 native palm species of the Brazilian Atlantic Forest, seeking to identify the best‐studied species and regions, main studied topics, overall patterns, trends and gaps in scientific research associated with this botany family. In total, studies were carried out for 48 species belonging to 10 genera, with the number of studies exponentially increasing from the 70s and exhibiting great difference in the number of publications among species. Euterpe edulis was the most studied species (n = 274), followed by Acrocomia aculeata (n = 205), whereas Bactris bahiensis (1), Geonoma litoralis (1), Syagrus santosii (1) and Trithrinax acanthocoma (0) comprised the less studied species. The largest number of studies was carried out in the south‐eastern states of Brazil. Regarding the type of studies, 34% and 27% were related to biochemical properties and ecological processes, respectively, while studies on entomology (n = 26), tissue culture (n = 23) and taxonomy (n = 7) showed the lowest number of studies. Given the key role of palms in tropical forests, our study suggests that future research should focus on less studied species, including Desmoncus spp., Geonoma spp. and Trithrinax sp., and on some less studied areas like the north‐east portion of the Atlantic Forest.