Bermejo, A. | Search bioRxiv

bioRxiv2023

Host space, not energy or symbiont size, constrains feather mite abundance across passerine bird species

Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constraints symbiont populations. We parameterized metabolic theory equations to predict how bird species body size and the body size of their feather mites relate to mite abundance according to four potential energy (microbial abundance, uropygial gland size) and space constraints (wing area, number of feather barbs). Predictions were compared with the empirical scaling of feather mite abundance from 26,604 birds of 106 passerine species, using phylogenetic modelling and quantile regression. Feather mite populations were strongly constrained by host space (number of feather barbs) and not energy. Moreover, feather mite species body size was unrelated to their abundance or to the body size of their host species. We discuss the implications of our results for our understanding of the bird-feather mite system and for symbiont abundance in general.

ecology↗

bioRxiv2020

Nutraceutical profiles of apricots (Prunus armeniaca L.) as a source of fruit quality traits for breeding

In a social context of increasingly concern about healthy diets, the development of new varieties with enhanced content in nutraceutical compounds is an increasingly important objective of the fruit breeding programs currently developed. In this sense, apricot is a fruit crop very appreciated by consumers due to its organoleptic characteristics, but also plays an important role in human nutrition due to its contain of phytocompounds as sugars, organic acids, vitamins and polyphenols. In this work, new selections from the apricot breeding program carried out at the Instituto Valenciano de Investigaciones Agrarias (IVIA) and traditional varieties have been analysed aimed at identifying sources of genetic variation for fruit quality. For this purpose, sugar content, organic acids and ascorbic acid were studied during two crop years. Results revealed sucrose and glucose as the major sugars, malic and citric acid as the main organic acids, and diverse ascorbic acid content among the cultivars studied. Results obtained pointed some accessions as potential sources to increase fruit quality. In addition, the study showed that apricot peel is an excellent source of nutraceutical compounds. Moreover, this study opens up new possibilities for future work to study the genetic control of these traits in apricot.

plant biology↗