Keule Research Articles

Seedling survival of the endangered Chilean tree Gomortega keule (Molina) Baill., queule

ABSTRACT Recruitment from seeds is a fundamental process for regeneration. Germination and seedling growth are especially important for trees’ conservation. Gomortega keule (queule) is an endemic and endangered Chilean evergreen tree growing in a small area within a global hotspot of biodiversity. Germination and seedling production in this species are not well understood, but presumed very limited. Populations are highly fragmented and threatened by land use change, especially forestry plantations, and fire damages. This study monitored G. keule seedlings in four sites over three years, recording the emergence and survival of seedlings in 24 plots located in four sites within patches of native vegetation surrounded by plantations of exotic forest trees. Seedling emergence occurred during springtime (October – December), lasting 40–70 days. After emergence, there was a sharp decline in seedling survival; 21.3% survived the first three months. Seedlings died more often in late spring. We confirmed that seedling emergence for G. keule is occurring. However, there is an absence of older seedlings and saplings. More studies are needed on the causes of death. Seedling survival in this endangered tree is essential for its long-term conservation and forest restoration.

Molinaʼs species of Lucuma: neotypifications and nomenclatural implications

The story of the life and botanical contributions of Juan Ignacio Molina (1740-1829), “the first Chilean scientist”, are briefly outlined. The generic name Lucuma is considered to be validly published by Molina in 1782, and the identities of the five species of the genus, L. bifera, L. turbinata, L. valparadisaea, L. keule, and L. spinosa, are discussed. Four species names are neotypified with material from Chile and the nomenclatural implications are discussed. Lucuma bifera, with L. turbinata in synonymy, becomes the name for the commonly cultivated Andean fruit tree in Sapotaceae currently called Pouteria lucuma. Gayella valparadisaea, with Lucuma valparadisaea in synonymy, becomes the name for the endemic Chilean tree in Sapotaceae currently called Pouteria splendens. Gomortega keule, with Lucuma keule in synonymy, remains the name for this endemic Chilean fruit tree in the monotypic family Gomortegaceae. Geoffroea decorticans, with Lucuma spinosa in synonymy, remains the name for this South American tree or shrub with edible fruits in Fabaceae.

Immature stages, phenology, distribution and host plants of the Andean Moon Moth Cercophana frauenfeldii Felder, 1862 (Lepidoptera: Saturniidae)

Abstract Cercophana frauenfeldii Felder (Lepidoptera: Saturniidae), also known as the “Andean Moon Moth”, is a Neotropical species native to continental Chile whose larvae feed on species of the families Gomortegaceae, Laureaceae and Winteraceae. We describe and document C. frauenfeldii immature stages, namely, egg, its four larval instars, and chaetotaxy of the last instar, pupa and cocoon for the first time. In terms of its phenology, we extend its larval activity, originally described to occur between November and mid-December, to June until the end of January. We report the adult flight period depends on the species’ distributional range following two well-differentiated patterns: February to mid-April in Central-North Chile and April to June in Central-South Chile. Furthermore, we provide a unified view of its current distributional range and host plants (including the endangered tree Gomortega keule) through bibliographic data, field observations and laboratory rearing. Finally, we discuss aspects of the species’ conservation as part of the unique ecosystems found in the temperate forests of southern South-America.

Anachronic Fruit Traits and Natural History Suggest Extinct Megafauna Herbivores as the Dispersers of an Endangered Tree.

Megafaunal seed dispersal syndrome refers to a group of traits attributed to the evolution of plants in the presence of large mammals. Present-day plants that bear these traits in areas where megafauna are absent are presumed to represent anachronic dispersal systems. Gomortega keule is an endangered tree species from a monotypic family (Gomortegaceae), endemic to Chile. Its fruit traits suggest adaptation to seed dispersal by large vertebrates; however, none are present today along its area of distribution. Here, we conducted a detailed revision on the fruit morphology of G. keule to examine whether its fruit traits fit a megafaunal dispersal syndrome. Additionally, we examined the fruit processing behavior of large domestic and captive wild animals fed with G. keule fruits, and its effect on germination. G. keule fruits had traits consistent with those of a Type 1 megafaunal fruit. Compared to intact, whole stones, seed germination probabilities decreased when fruits were handled by animals, suggesting that the seed was damaged during mastication and/or ingestion. Moreover, results from our feeding trials with elephants may also imply low efficiency of extinct gomphotheres as seed dispersers of this species. Our results also suggest that although domestic animals may disperse G. keule, it is unlikely that at present they can substitute the services of its original dispersers. Further investigation on seedling survival, local livestock management and forest management practices may help reinstate sexual regeneration in G. keule. Finally, integrating observations on fruit ecology and local people’s knowledge with experimental data enriches our species-centered approach and may help to address regeneration problems in other endangered plants.

The endospermic origin of the storage tissue of a rare tree endemic to Chile, Gomortega keule, is confirmed by microsatellites

ABSTRACT In angiosperms, the usual storage tissue found in seeds is the endosperm, which originates at the characteristic event of the double fertilisation. The mature seeds of Gomortega keule (Molina) Baillon, in the monotypic family Gomortegaceae, contain a storage tissue composed of two distinct parts. This uncommon form suggests one of the parts may actually correspond to perisperm. In this work we aimed to combine genetic and histological observations to determine the endospermic origins of the two tissue parts. Seven microsatellite DNA loci were amplified and genotyped. Genetic profiles of tissue parts were grouped in expected classes following the model of the double fertilisation of angiosperms. The majority of observations matched those expected classes. Genotyping inconsistencies could be attributed to fruits that were mistakenly assigned to a maternal tree, or due to null alleles or mutations. In observations made from histological preparations, the outer part of the storage tissue represents a larger proportion in mature seeds than is found in young seeds, suggesting that the outer part of the storage tissue develops later than the inner part. The observations of the endosperm, a single cell layer of perisperm, and details of the seed coat, show that there was no evidence that the perisperm has any continuity with the storage tissue. This finding suggested a common endospermic origin for the two parts of the storage tissue. There was a cell layer in between the inner and outer part of the endosperm, which has not been previously reported, and it supports the finding of differentiation of the two endosperm parts. The pattern of two tissue parts in the endosperm of G. keule is a unique feature among angiosperm plants. The observations suggest early stages of evolution towards a greater histological differentiation of the endosperm parts in this species.

Impact of habitat loss and fragmentation on reproduction, dispersal and species persistence for an endangered Chilean tree

Survival of rare and endangered plant species following habitat loss and fragmentation is dependent upon in situ reproduction and population persistence, and establishment in new sites, so that stochastic, local extirpation does not lead to species extinction. Here we investigate if and how vegetative and sexual reproduction, propagule dispersal, and seedling establishment promote in situ persistence and establishment in new sites for the endangered, endemic Chilean tree Gomortega keule, in a landscape experiencing extensive habitat loss and fragmentation. Genetic analyses show G. keule reproduces vegetatively, producing large clone groups and providing a mechanism for long-term in situ persistence. Abundant seed set was observed, but seedling establishment was rare. At the single site where seedlings were observed, parentage analysis revealed seed dispersal over greater distances, and in a more aggregated pattern, than would be expected from gravity dispersal alone. We hypothesize that G. keule may represent a ‘seed dispersal anachronism’, wherein the native seed disperser has been lost and possibly replaced by domesticated cattle. The lack of seedling establishment at most sites raises concerns about the ability of existing populations to expand within existing habitat patches or establish at new locations. Globally, habitat loss and fragmentation, coupled with other environmental changes, pose a particular threat to rare species with small populations, because inbreeding and the loss of mutualists can lead to establishment failure and local extirpation. We propose that analysis of a plant’s reproductive strategies as a whole, in its landscape context, is essential for effective species conservation.

Flora vascular de un remanente de bosque esclerófilo mediterráneo costero: Estación de Biología Terrestre de Hualpén, Región del Biobío, Chile

The remnants of coastal Mediterranean sclerophyll forests in Chile have a low representativeness in the National System of Protected Wild Areas despite their high endemism and species richness. In the Biobio Region, the Hualpen Terrestrial Biology Station (EBT) protects a remnant of this type of forest, for which there are no revisions describing its flora, which makes it difficult to formulate and develop strategies for its protection and conservation. This work aims are: a) to describe the taxonomic composition of vascular plants of the ETB and b) to provide information on their geographical origin, habit and conservation status. The resulting floristic list includes species identified through systematic sampling in the study area for one year, as well as EBT species stored in the collection of the Universidad de Concepcion Herbarium. We identified 292 species of vascular plants, where 71 species are endemic, 124 are native, 99 are alien species. From the floristic point of view the Asteraceae family was the most diverse with 36 species, followed by Poaceae with 32 species and Fabaceae with 18 species. Herbs were the most frequent growth habit (77.2%), followed by shrub (13.9%), tree (7.5%) and sub-shrub (1.4%). Nineteen endemic and native species have been classified in some category of conservation in continental Chile, standing out Gomortega keule and Pitavia punctata both classified as endangered species, and the fern Asplenium trilobum classified as a least concern in Chile and vulnerable in the Biobio Region. Despite of the reduced protected area in the EBT (70 ha), the site has a high species richness of native species when compared with data obtained from other studies of flora in sites of central Chile.

The endosperm of a rare tree endemic to Chile, Gomortega keule, has two parts with different chemical composition

ABSTRACT‘Queule’ (Gomortega keule) is an endemic and endangered Chilean tree belonging to the monotypic family Gomortegaceae. Inside its edible fruit the usually single seed has an oily endosperm divided in two distinctive parts; this represents a unique organisation of storage tissue in angiosperm seeds. Since this trait has not been previously reported in literature, this study aimed to describe both parts of the storage tissue and to identify the presence of lipid, starch and protein. Seeds were observed using the paraffin method and handmade slices. Specific dyes were applied to identify chemical compounds. Oil content was quantified in both parts of the endosperm. Additionally, seed and embryo size were measured from endocarps collected from the forest floor during an 8 month period. Increased embryo size and absence of germination suggest morphological dormancy. Histological slices showed abundant and larger starch grains in the inner part of the endosperm, and lower presence of proteins compared to the outer part. In terms of oil content, the inner part of the endosperm contained 27% (w/w fresh weight), the embryo 22% and the outer part 20%. Although both parts of the storage tissue are notoriously different, both belong to the endosperm. The presence of oil, proteins and starch in the storage tissue may provide ecological advantages for seedling establishment.

Microsatellite analysis of populations of the endangered tree Gomortega keule suggests pre-Columbian differentiation

ABSTRACTTemperate forests have been affected extensively by human activities, resulting in land cover changes and population fragmentation. However, these anthropogenic effects can be superimposed onto the natural history of species, making it difficult to determine which effect is more important for a particular species. Gomortega keule is an endangered tree that is found in one of the world’s biodiversity hotspots in central–south Chile. Human activities have significantly impacted on the original habitat in this region in recent years and are commonly considered to be the main cause of the scarcity of this species. However, aspects of the natural history of this evergreen tree may also help to explain its present-day genetic structure. In this study, we undertook microsatellite genotyping of the two southernmost populations of G. keule, which are 7.5 km apart and well isolated from other populations. We found that there was genetic differentiation between these populations, suggesting that they exhibited at least some differentiation before becoming isolated, most likely before human activities first impacted the region some two centuries ago. Molecular estimates of their divergence time supported a more ancient differentiation of the populations than would be explained by human activities alone. It is possible that their isolation may have followed the extinction of megafaunal seed dispersers around 12,000 years before present in this region, as indicated by fruit characteristics, the absence of recruitment by seedlings and the existence of clonal trees.

Culture of triploid tissue from the endosperm of an endangered Chilean tree species Gomortega keule

ABSTRACTThe endangered Chilean tree species Gomortega keule (Mol.) Baillon produces an edible fruit, but is not cultivated at present. Recent advances in micropropagation may allow the further development of this species as a fruit crop. Triploid plants have been regenerated from the endosperm of seed of a number of species. This is the first report on in vitro culture of the seed endosperm of G. keule in order to obtain triploid plants. Callus was formed from endosperm after 1.5 months on 1.0× Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid and 6-(γ,γ-dimethylallylamino) purine. Shoot primordia developed and produced shoots that could be cultured on Rugini medium containing 0.1 mg l–1 α-naphthaleneacetic acid and 1 mg l–1 6-benzyladenine. Shoot primordia cultured on Rugini medium containing 2 g l–1 activated charcoal produced longer shoots and longer leaves compared to diploid genotypes. Flow cytometry and chromosome observations indicated that the callus tissue and plantlets derived from the seed endosperm were triploid. Endosperm culture represents a feasible method to regenerate triploid plantlets of this tree species within 18 months. Such material may be of value for the genetic improvement and future development of G. keule as a commercial fruit tree species.

Notes on a new population of the endangered Chilean tree Gomortega keule

The evergreen tree Gomortega keule (Mol.) Baillon belongs to the monotypic family Gomortegaceae and produces edible fruits. This endangered species occurs along a 200 km stretch of the coastal ranges in central Chile, fragmented in small populations at 24 localities with difficult access. Within the geographic area the present work describes a population not reported previously. Most of the 73 individuals found showed several shoots or thin trunks re-growing from damaged trees under the canopy of a forestry plantation. Only three individuals had shoots with a diameter at breast height over 10 cm. The height of the trees was less than 10 m. In more than 80% of cases, cut or burnt remains of a central trunk indicated that the original trees were damaged. These observations, and the absence of flowers, fruits and seedlings, show that the entire population is the result of vegetative regeneration. Threats posed to the species by forestry activities and fire are discussed.

Bioactive coumarins and HPLC-PDA-ESI-ToF-MS metabolic profiling of edible queule fruits (Gomortega keule), an endangered endemic Chilean species

The endemic Chilean tree Gomortega keule (Molina) Baillon (Gomortegaceae) was highly appreciated for its edible fruits. Due to substitution of the native forest by tree monocultures, this species in now endangered. Antioxidant assay-guided fractionation of the methanolic extract led to the isolation of eight antioxidant compounds, including rare highly oxygenated coumarins, besides the more common antioxidant compounds chlorogenic acid (compound 6) and rutin (compound 16). The isolation of the compounds was achieved by preparative reverse phase HPLC and the structural elucidation was performed using 1H and 13C NMR techniques. A metabolomic fingerprint was generated and 32 compounds were detected and analyzed on the basis of HPLC-PDA and HR-ESI-ToF-MS. The total phenolic and flavonoid contents of the fruits were determined by spectroscopic means. The content of the major compounds chlorogenic acid (6) and dimethylfraxetin (22) was 51.80±1.49mg/100g dry weight and 9.57±0.11mg/100g dry weight, respectively, while compounds 6 and 16 showed the highest antioxidant capacity (42.37±3.72μg/ml and 23.91±1.50μg/ml in the DPPH scavenging assay, respectively). This is the first report of antioxidant capacity and polyphenolic content of the edible queule fruits.

Variabilidad genética mediante AFLP en tres relictos de Gomortega keule (Molina) Baillon: especie endémica chilena en peligro de extinción

Gomortega keule is an endemic woody species to Chile and the only member of the Gomortegaceae family. It is currently an endangered species and is of great scientific interest due to its small area of distribution. The aim of this research was to estimate genetic diversity of 24 individuals of G. keule selected from three isolated relict populations from the province of Concepcion using AFLP (Amplified fragment length polymorphism) for future conservation issue. Sixteen combinations of primers for AFLP were tested and three combinations of them were selected as the most informative, revealing differences between individuals. These primer combinations generated 156 fragments, of which 62 % were polymorphic. The relict population with the highest percentage of polymorphisms was located in Cerro Neuque with 84.6 %, followed by Coroney and Hualqui with 59.6 and 42.3 %, respectively. The analysis of molecular variance detected 73 % variation within populations and 27 % variation amoung populations. This study supported that AFLP can be used in G. keule as a fast and reliable test to identified remaining populations of the species. Thus, this technique can be used to support ex situ or in situ conservation of G. keule.

Ethnobotany of Gomortega keule, an endemic and endangered Chilean tree

Gomortega keule (Mol.) Baillon, known locally as queule, is an endangered tree endemic to Chile. The literature states that the main uses of this species are fruit consumption and exploitation of the wood, but there are no in-depth references to other uses. Some references mention that the fruit produces a putative psychoactive effect. Because non-documented ethnobotanical knowledge may still be maintained by local people, this study aimed to gather information on traditional knowledge and uses of this tree. Local inhabitants in five localities were interviewed using semi-structured interviews. The main uses of the species already published were confirmed and detailed as more in-depth. Additionally, uses not previously described were found: for flavouring, dye and marbles. These uses are discussed, including the controversy about the inebriating effect of the fresh fruit.

Flowering and fruiting phenology of the endangered Chilean tree Gomortega keule

Gomortega keule is endemic to Chile and belongs to the monotypic family Gomortegaceae. Although it produces edible fruits and good-quality wood, it is not cultivated. Information on reproductive phenology may help address conservation and cultivation practices. However, there is limited knowledge about this species. This research aimed to investigate the phenology of G. keule. Inflorescences and fruits were monitored over one year in a natural population. Flower bud development extended from early January to April (summer to mid-autumn). Flowering peaked from late April to mid May, while fruitset occurred from autumn to late spring. The fruits seemed to have originated in different years, as supported by a number of observations. From these observations, a complete fruit phenology was inferred, with a notably long growth period, suggesting that 17–20 months are required from fruitset to senescent fruit fall.

Somatic embryogenesis from zygotic embryos and shoot-tips of the Chilean tree Gomortega keule

The endangered Chilean tree Gomortega keule (Mol.) Baillon produces edible fruit, making it a potential crop. However, its cultivation from seed or cuttings is extremely difficult. This paper reports the induction of somatic embryogenesis and the initiation of liquid cultures in this species. Callus was induced from zygotic embryos and field-collected shoots. Somatic embryogenesis on zygotic embryos occurred at a low frequency. Induction of somatic embryogenesis was accomplished on micropropagated shoots after 6.5 months on semi-solid Murashige and Skoog (MS) medium with 30 g/l sucrose, 1.0 mg/l 2,4-dichlorophenoxyacetic acid and 1.0 mg/l 6-(γ,γ-dimethylallylamino) purine (2iP). Liquid cultures of compact callus and small aggregates were obtained and showed optimum proliferation in MS medium with 20 g/l sucrose, 0.01 mg/l α-naphthaleneacetic acid and 0.1 mg/l 2iP. The proliferation of friable embryogenic callus was observed in liquid medium and will allow the propagation of selected genotypes of this tree on a large scale. Genetic variation in two embryogenic genotypes cultured in vitro was not detected in an assessment using microsatellites; this approach is suitable for tracing genotypes.

The Circe Principle Explains How Resource-Rich Land Can Waylay Pollinators in Fragmented Landscapes

Global declines in pollinators, associated with land-use change [1-6] and fragmentation [7-10], constitute a serious threat to crop production and biodiversity [11]. Models investigating impacts of habitat fragmentation on pollen flow have categorized landscapes simply in terms of habitat and nonhabitat. We show that pollen flow depends strongly on types of land use between habitat fragments. We used paternity analysis of seeds and a combination of circuit and general linear models to analyze pollen flow for the endangered tree Gomortega keule (Gomortegaceae) [12] in the fragmented Central Chile Biodiversity Hotspot [13]. Pollination probability was highest over pine plantation, moderate over low-intensity agriculture and native forest, and lowest over clearfells. Changing the proportions of the land uses over one kilometer altered pollination probability up to 7-fold. We explain our results by the novel "Circe principle." In contrast to models where land uses similar to native habitat promote pollinator movement, pollinators may actually be waylaid in resource-rich areas between habitat patches. Moreover, pollinators may move with higher probability between habitat patches separated by some resource-poor land uses. Pollination research in fragmented landscapes requires explicit recognition of the nature of the nonhabitat matrix, rather than applying simple binary landscape models.

Gomortega keule, the neglected and endangered Chilean fruit tree

Gomortega keule (Mol.) Baillon is the only species belonging to the family Gomortegaceae and is regarded as an ancient surviving lineage within the Laurales. The tree is restricted to a small geographical area of the coast of central Chile, where it is in danger of extinction. Its edible fruits and excellent quality wood have been known from the earliest records of the species in the sixteenth and seventeenth centuries. This review consolidates many publications that are dispersed in the literature, covering aspects of taxonomy, morphology, systematics, propagation, biogeography, ecology, conservation and ethnobotany. Large gaps are present in our knowledge of the species, since many cited publications provide only brief descriptions or statements on diverse aspects of the tree. A limited number of publications represent formal research effort. Surprisingly, there is no major initiative aimed at the systematic cultivation of Gomortega, which is an excellent candidate for domestication, especially for fruit production.

Micropropagation of the endangered Chilean tree, Gomortega keule

The endangered tree Gomortega keule remains only in small, isolated populations surrounded by timber plantations in the biodiversity hotspot of central Chile. This species, belonging to the monotypic family Gomortegaceae, produces edible fruit and high-quality wood, but its difficult propagation makes conservation essential. The percentage of seed germination is less than 40%, germination time exceeds 12 mo, and cuttings fail to root. These difficulties have stimulated efforts to explore in vitro approaches for propagation. Cultures were established from zygotic embryos; the optimum culture conditions for shoot proliferation were semi-solid Woody Plant Medium (WPM) with 20 g/l sucrose, 0.1 mg/l α-naphthaleneacetic acid and 1.0 mg/l 6-benzylaminopurine, at 18°C. Explants required about 12 mo in culture before stabilized growth resulted in consistent shoot production. Regenerated shoots excised from parental explants developed a normal morphology 1 mo after transfer to WPM with 2.0 g/l of activated charcoal, and lacking plant growth regulators. These normal shoots were rooted with a treatment of 7 d on WPM without activated charcoal, but containing 20 mg/l indole-3-butyric acid, followed by return to the same medium with 2.0 g/l activated charcoal, without growth regulators, for 1 mo. Regenerated plants were transferred to compost and covered with transparent plastic sleeves. The latter were opened gradually to decrease humidity and to establish plants under glasshouse conditions. There is an urgent requirement to extend this protocol to material collected from diverse sites and to introduce micropropagated specimens into the wild and living plant repositories to conserve this endangered species.

Fragmented but not isolated: Contribution of single trees, small patches and long-distance pollen flow to genetic connectivity for Gomortega keule, an endangered Chilean tree

Habitat fragmentation is a major threat to species survival worldwide due to genetic isolation, inbreeding depression, genetic drift and loss of adaptive potential. However the data on how gene-flow changes following habitat fragmentation is contradictory. If there is significant gene-flow between spatially isolated populations then limited conservation resources could be directed away from projects to ‘establish genetic connectivity’ and used to address other consequences of habitat fragmentation. This research focused on an endangered tree species Gomortega keule (Gomortegaceae) in a fragmented landscape in the Central Chile Biodiversity Hotspot and addressed three questions: (1) How far does pollen move between pollen donors and seed trees and what is the shape of the dispersal curve? (2) Do insect pollinators travel outside of forest patches? (3) Do small populations and single trees contribute to genetic connectivity across the landscape? Paternity analysis results show that G. keule’s insect pollinators travel outside of forest patches, over distances of 6 km, beyond the scale of population fragmentation or genetic structure. Pollen moved from small sites and single trees into large sites, as well as in the other direction, indicating these sites play a key role as functioning elements of the wider population and as stepping stones between sites. Fragmentation at the scale investigated has not led to genetic isolation, thus genetic connectivity per se is not a conservation priority. Other consequences of land-use change, specifically continuing habitat loss and population reduction, still threaten the survival of the species.