Adult insect personality in the wild -- Calopteryx splendens as a model for field studies

Animal personality has received increasing interest and acknowledgement within ecological research over the past two decades. However, some areas are still poorly studied and need to be developed. For instance, field studies focused on invertebrates are currently highly underrepresented in the literature. More studies including a wider variety of traits measured and species tested is needed to improve our understanding of trait-correlation patterns and generalities. We studied nine behavioural traits, in the damselfly Calopteryx splendens, from an array of three experiments: (i) courtship, (ii) aggressiveness and (iii) boldness, and calculated their repeatability. The behaviours were measured twice, in two different contexts: (i) undisturbed territory and (ii) partially deteriorated territory. All behavioural traits measured, except for two, were repeatable across the two contexts. This work demonstrates, for the first time, the presence of within population personality differences in an adult damselfly in the wild. We further propose Calopteryx splendens as a promising model species for testing personality in the wild under highly controlled environmental conditions.

What Determines Host Range and Reproductive Performance of an Invasive Ambrosia Beetle Euwallacea fornicatus; Lessons From Israel and California

This study examined the polyphagous shot hole borer (PSHB) Euwallacea fornicatus (Coleoptera; Scolytinae) native to Southeast Asia and concentrated on its wide host range in two of the invaded areas, California and Israel. Among the 583 examined tree species, 55.9% were characterized as “non-reproductive hosts” and only 13.8% were characterized as “reproductive hosts,” suitable for the E. fornicatus reproduction. Families that included ≥20 species and genera with ≥10 were considered for further analysis. The highest percentage of tree species suitable for reproduction was obtained for Salicaceae and Sapindaceae, whereas the lowest percentage of tree species belonging to this category were within the Rosaceae, Myrtaceae, and Magnoliaceae. The genera Acer, Quercus and Acacia displayed the highest percentage within the “reproductive host” category, with the former significantly higher from all seven of the studied genera. We found that all Brachychiton and Erythrina were attacked and none of the examined 20 Eucalyptus spp. were suitable for E. fornicatus reproduction. The results suggest discordance between host tree phylogeny and susceptibility to the E. fornicatus, indicating that trait correlation of susceptibility of different tree species to the E. fornicatus are the results of convergent evolution and not of a common descent. A theoretical model, suggesting the different possibilities of potential tree species becoming attractive or non-attractive to E. fornicatus attack, is described. It is suggested that the beetle reproduction success rate over a wide host range, as well as the long list of species belonging to the “non-reproductive host” category, is the outcome of interactions between the beetle fungal symbiont, F. euwallaceae, and sapwood of the attacked tree. The model suggests that a tree selected by the E. fornicatus may fall in one of three groups, (i) those in which F. euwallaceae is unable to develop, (ii) those tree species that slow the development of the fungus, and (iii) those that enable F. euwallaceae to thrive. Hence, the host range suitable for beetle reproduction is determined by development of F. euwallaceae. In general, PSHB does not distinguish between host species of the “non-reproductive host” and “reproductive host” categories.

Natural selection on traits and trait plasticity in Arabidopsis thaliana varies across competitive environments

Interspecific competition reduces resource availability and can affect evolution. We quantified multivariate selection in the presence and absence of strong interspecific competition using a greenhouse experiment with 35 natural accessions of Arabidopsis thaliana. We assessed selection on nine traits representing plant phenology, growth, and architecture, as well as their plasticities. Competition reduced biomass and fitness by over 98%, and plastic responses to competition varied by genotype (significant G × E) for all traits except specific leaf area (SLA). Competitive treatments altered selection on flowering phenology and plant architecture, with significant selection on all phenology traits and most architecture traits under competition-present conditions but little indication that selection occurred in the absence of competitors. Plasticity affected fitness only in competition-present conditions, where plasticity in flowering time and early internode lengths was adaptive. The competitive environment caused changes in the trait correlation structure and surprisingly reduced phenotypic integration, which helped explain some of the observed selection patterns. Despite this overall shift in the trait correlation matrix, genotypes with delayed flowering had lower SLA (thicker, tougher leaves) regardless of the competitive environment, a pattern we have not seen previously reported in the literature. Overall, our study highlights multiple ways in which interspecific competition can alter selective regimes, contributing to our understanding of variability in selection processes over space and time.

Evaluation of the morphological diversity of tea roses (Rosa x odorata) based on phenotypic traits

Rosa x odorata (sect. Chinenses, Rosaceae) is an important species distributed only in Yunnan Province, China. There is an abundance of wild variation within the species. Using 22 germplasm resources collected from the wild, as well as R. chinensis var. spontanea, R. chinensis ‘Old Blush’ and R. lucidissima, this study involved morphological variation analysis, inter-trait correlation analysis, principal component analysis and clustering analysis based on 16 morphological traits. This study identified a high degree of morphological diversity in R. x odorata germplasm resources and the variation coefficients had a distribution range from 18.00 to 184.04%. The flower colour had the highest degree of variation, while leaflet length/width had the lowest degree of variation. Inter-trait correlation analysis revealed that there was an extremely significant positive correlation between leaflet length and leaflet width. There was also a significant positive correlation between the number of petals and duration of blooming, and the L* and a* values of flower colour were significantly negatively correlated. Principal component analysis screened five principal components with the highest cumulative contribution rate (81.679%) to population variance. Among the 16 morphological traits, style length, sepal width, flower diameter, flower colour, leaflet length and leaflet width were important indices that influenced the morphology of R. x odorata. This study offers guidance for the further development and utilization of R. x odorata germplasm resources.

Assessment of Genetic Variability, Diversity and Trait Correlation Analysis in Common Bean (Phaseolus vulgaris L.) Genotypes

The present investigation was undertaken to study the genetic variability, diversity through cluster analysis and correlation among yield attributing traits. The experimental material is comprised of 63 diverse germplasm accessions including three check varieties were evaluated in augmented design during Rabi 2015-16 at IIPR, Kanpur. In this study, totally nine traits, namely, days to fifty per cent flowering (DF), days to maturity (DM), plant height (PH), number of branches per plant (NBP), number of pods per plant (NPP), pod length (PL), seeds per pod (SPP), 100 seeds wt (g) (HSW) and seed yield per plant (g) (SYP) were recorded. The results exhibited that the analysis of variance noticed significant differences among the genotypes for all characters studied. The genetic variability parameter showed that phenotypic coefficient of variation (PCV) were higher than those of genotypic coefficient of variation (GCV) for all the traits studied. Higher GCV coupled with heritability and genetic advance as % mean was recorded for PH, NPP, HSW and SYP. Likewise, high heritability coupled with high genetic advance as % mean was recorded in DF, PH, NPP, PL, HSW and SYP. Trait association study revealed that the seed yield per plant exhibited significant positive correlation with NBP, NPP, NSP and HSW. In the same pattern, Euclidian clustering analysis displays 63 genotypes were grouped to two major clusters. From this investigation, it was observed that all genotypes showed sufficient genetic variability for the traits studied. The genotype such as EC400414, EC400398, ET8415 and EC540173 were superior to check varieties in terms of morphological and other agronomic traits. These genotypes could be utilized in breeding programme for improvement of specific traits.

Phenotypic Variations and Heritability in Hybrid Populations of Bearded Iris

Bearded iris (Iris ×hybrida Hort.) is a large horticultural hybrid complex in the Iris genus, and the lack of understanding about its inheritance laws has seriously hindered the breeding process. From parental bearded iris ‘Indian Chief’ and ‘Sugar Blues’, four hybrid populations—including F1, F2, BC1P1, and BC1P2—were generated through hybridization. Fifteen key phenotypic traits, including plant height (PH), scape height (SH), length of fall (LF), width of fall (WF), length of standard (LS), width of standard (WS), and so on, were measured, and several genetic parameters (e.g., trait variation, heritability, trait correlation, distribution of flower color) were analyzed. The variation of phenotypic traits indicated that the F1 generation could produce larger flowers and a greater number of blooming stems than other generations, whereas backcrossing was beneficial at producing more flowers on one scape in the offspring of ‘Indian Chief’ and ‘Sugar Blues’. WF had the greatest broad-sense heritability (73.91%) among the 15 phenotypic traits, whereas the broad-sense heritability of SH was the lowest (2.06%). The correlation between a vegetative trait (PH) and a reproductive trait (WS) provided a path to early selection of germplasm. Furthermore, four important floral traits (LF, WF, LS, and WS) also correlated significantly to each other, thus simplifying the selection of larger flowers. Genes regulating fuchsia flower color were dominant over those for bluish purple flowers. Genetic effects of flower color in recurrent parents could be reinforced by backcrossing, thereby providing a potential way to modify flower color through hybridization.