Root positioning and trait shifts in Hibbertia racemosa as dependent on its neighbour's nutrient-acquisition strategy.

Nutrient-poor ecosystems globally exhibit high plant diversity. One mechanism enabling the co-existence of species in such ecosystems is facilitation among plants with contrasting nutrient-acquisition strategies. The ecophysiological processes underlying these interactions remain poorly understood. We hypothesized that root positioning plays a role between sympatric species in nutrient-poor vegetation. We investigated how the growth traits of the focal mycorrhizal non-cluster-rooted Hibbertia racemosa change when grown in proximity of non-mycorrhizal Banksia attenuata, which produces cluster roots that increase nutrient availability, compared with growth with conspecifics. Focal plants were placed in the centre of rhizoboxes, and biomass allocation, root system architecture, specific root length (SRL), and leaf nutrient concentration were assessed. When grown with B. attenuata, focal plants decreased root investment, increased root growth towards B. attenuata, and positioned their roots near B. attenuata cluster roots. SRL was greater, and the degree of localized root investment correlated positively with B. attenuata cluster-root biomass. Total nutrient contents in the focal individuals were greater when grown with B. attenuata. Focal plants directed their root growth towards the putatively facilitating neighbour's cluster roots, modifying root traits and investment. Preferential root positioning and root morphological traits play important roles in positive plant-plant interactions.

Optimizing the genetic composition of a translocation population: Incorporating constraints and conflicting objectives.

Translocations of threatened species can reduce the risk of extinction from a catastrophic event. For plants, translocation consists of moving individuals, seeds, or cuttings from a native (source) population to a new site. Ideally a translocation population would be genetically diverse and consist of fit founding individuals. In practice, there are challenges to designing such a population, including constraints on the availability of material, and tradeoffs between different goals. Here, we present an approach for designing a translocation population that identifies sets of founders that are optimized according to multiple criteria (e.g., genetic diversity), while also conforming to constraints on the representation of different founders (e.g., propagation success). It uses flexible inputs, including SNP genotypes, matrices of similarity between individuals, and vectors of phenotype data. We apply the approach to a critically endangered plant, Hibbertia puberula subsp. glabrescens (Dilleniaceae), which was genotyped at thousands of SNP loci. The goals of minimizing genetic similarity among the founding individuals and maximizing genetic diversity were largely complementary: populations optimized for one of these criteria were near-optimal for the other. We also performed analyses in which we minimized genetic similarity among founding individuals while imposing selection (against hypothetical deleterious alleles, and against undesirable phenotypes, respectively), and here characterized sharp tradeoffs. This was useful in allowing the benefits of selection to be weighed against costs in terms of genetic similarity. In summary, we present an approach for designing a translocation population that allows flexible inputs, the imposition of realistic constraints, and examination of conflicting goals.

An overview of inventories of gall-inducing insects in Brazil: looking for patterns and identifying knowledge gaps.

We compiled published Brazilian gall-inducing insect inventories aiming to understand trends and biases in this field research and to investigate the factors that potentially explain the diversity of gall-inducing insects among different sampling sites. A total of 51 studies with gall-inducing insect inventories were compiled for Brazil, which sampled 151 sites in 88 municipalities, 13 states and five regions. The number of papers published on gall-inducing insects per year has increased over the last 30 years, being Cecidomyiidae (Diptera) the main galling taxon, Fabaceae the main host-plant family and Protium heptaphyllum (Burseraceae) the most important super-host species in these inventories. We found a great bias in the geographical distribution of Brazilian inventories, with the majority of studies in the Southeast region, and Atlantic Forest and Cerrado biomes. The total richness of gall-inducing insects differed significantly among regions and biomes, with higher gall richnesses being recorded in the North region and Amazon biome. However, Brazilian regions and biomes did not vary in richness of gall-inducing insect morphotypes per plant species. According our results, sampling by cecidologists in less studied regions of Brazil is needed, particularly in the North and South regions and subsampled biomes such as the Amazon, Pampas and Pantanal.

Lopesia davillae (Diptera, Cecidomyiidae), a new species of gall midge from Brazil associated with Davilla rugosa (Dilleniaceae) / Lopesia davillae (Diptera, Cecidomyiidae), uma nova espécie de cecidomiídeo do Brazil associada à Davilla rugosa (Dilleniaceae)

Abstract Lopesia davillae, a new species of gall midge associated with the reproductive structures of Davilla rugosa (Dilleniaceae), is described and illustrated (larva, pupa, male, female, and damage) based on material collected in Rio de Janeiro, Brazil. This new species is compared with its congeneric species. This is the first record of Lopesia on Dilleniaceae.

Resumo Lopesia davillae, uma nova espécie de Cecidomyiidae associada a estruturas reprodutivas de Davilla rugosa (Dilleniaceae), é descrita e ilustrada (larva, pupa, macho, fêmea e dano) com base em material coletado no estado do Rio de Janeiro, Brasil. A nova espécie é comparada com as outras espécies conhecidas do mesmo gênero. Este é o primeiro registro de Lopesia em Dilleniaceae.

Lopesia davillae (Diptera, Cecidomyiidae), a new species of gall midge from Brazil associated with Davilla rugosa (Dilleniaceae).

Lopesia davillae, a new species of gall midge associated with the reproductive structures of Davilla rugosa (Dilleniaceae), is described and illustrated (larva, pupa, male, female, and damage) based on material collected in Rio de Janeiro, Brazil. This new species is compared with its congeneric species. This is the first record of Lopesia on Dilleniaceae.