Unraveling plant-pollinator interactions from a south-west Andean forest in Colombia.

Background: Loss of biological connectivity increases the vulnerability of ecological dynamics, thereby affecting processes such as pollination. Therefore, it is important to understand the roles of the actors that participate in these interaction networks. Nonetheless, there is a significant oversight regarding the main actors in the pollination networks within the highly biodiverse forests of Colombia. Hence, the present study aims to evaluate the interaction patterns of a network of potential pollinators that inhabit an Andean Forest in Totoró, Cauca, Colombia. Methods: The interactions between plants and potential pollinators were recorded through direct observation in 10 transects during six field trips conducted over the course of one year. Subsequently, an interaction matrix was developed, and network metrics such as connectance, specialization, nestedness, and asymmetry of interaction strength were evaluated by applying null models. An interpolation/extrapolation curve was calculated in order to assess the representativeness of the sample. Finally, the key species of the network were identified by considering degree (k), centrality, and betweenness centrality. Results: A total of 53 plant species and 52 potential pollinator species (including insects and birds) were recorded, with a sample coverage of 88.5%. Connectance (C = 0.19) and specialization (H2' = 0.19) were low, indicating a generalist network. Freziera canescens, Gaiadendron punctatum, Persea mutisii, Bombus rubicundus, Heliangelus exortis, Chironomus sp., and Metallura tyrianthina were identified as the key species that contribute to a more cohesive network structure. Discussion: The present study characterized the structure of the plant-pollinator network in a highly diverse Andean forest in Colombia. It is evident that insects are the largest group of pollinators; however, it is interesting to note that birds form a different module that specializes in pollinating a specific group of plants. On the other hand, the diversity and generality of the species found suggest that the network may be robust against chains of extinction. Nevertheless, the presence of certain introduced species, such as Apis mellifera, and the rapid changes in vegetation cover may affect the dynamics of this mutualistic network. So, it is imperative to apply restoration and conservation strategies to these ecosystems in order to enhance plant-animal interactions and prevent the loss of taxonomical and functional diversity.

Effect of environmental conditions on the changes of voltinism in three lines of Bombyx mori.

This work aims to estimate the voltinism differences in the studied lines and the influence of biological and environmental variables on this trait. Three Bombyx mori. lines were used. One polyvoltine (Indian, C. Nichi) and two bivoltine (Chinese6-C6 and Japanese7-J7). Silkworms were reared under controlled conditions of temperature (24±1, 26±1, 28±1°C) and photoperiod (8-16, 12-12, 16-8 light/darkness) during the life cycle. The measured biological characters were duration of larval period (DLP), larval weight on fifth day of V instar (LW(V-5)), rate of weight (RWV), duration of life cycle (DLC), fecunditiy (NE), fertility (F) and voltinism (V). Voltinism was estimated using a linear regression model; the variables that influence voltinism were found using a multiple regression analysis; and the effect of environmental conditions on change of voltinism employing an ANOVA. The results show that the variables that affect voltinism are different for each line, which demonstrates the effect of the line factor. Nichi voltinism was affected by the six measured variables, while in C6 and J7 where voltinisms depends on the duration of diapause, some variables were excluded from the model. In Indian tropical polyvoltine, the temperature was the influencing factor, while in Chinese and Japanese bivoltines lines was the photoperiod.

Genetic parameters in traits of productive importance in lines of Bombyx mori L.

In the textile industry, complex cocoon traits are closely related to silk production. The aim of the present study was to estimate genetic parameters of economic importance traits-cocoon length (CL), cocoon weight (CW) and shell weight (SW)-in three B. mori lines-Chinese (C6), Japanese (J7) and Indian (C. Nichi)-reared under different temperature and photoperiod conditions. For each of these lines, data were collected from several generations with a full-sibling family structure and variance-covariance component were obtained via restricted maximum likelihood (REML) estimates based on a bi-trait animal model analysed through the multiple-trait derivative-free restricted maximum likelihood (MTDFREML) software. Genetic parameters of the traits varied between the silkworm lines were evaluated. Heritabilities were highest in J7 line (0.71, 0.89 and 0.93 for CL, CW and SW, respectively) followed by C6 (0.48, 0.54 and 0.50 for CL, CW and SW, respectively) and C. Nichi (0.36, 0.43 and 0.40 for CL, CW and SW, respectively). Phenotypic correlations among these lines were positive, with values ranging between 0.36 and 0.767. Similarly, genetic correlations between the analysed silkworm lines were observed to be positive, with high values ranging from 0.86 to 0.94. The evidence for environmental correlation in these lines was found only between CW-SW traits with moderate to high values ranging from 0.600 to 0.940. The magnitude of heritability and genetic correlations implies that phenotypic variations of the CL, CW and SW traits depend mainly on genotypic variation within the J7, C6 and C. Nichi lines, and that simultaneous genetic gains are possible by implementing selection processes for any of the evaluated traits.

Role of microsatellites in genetic analysis of Bombyx mori silkworm: a review.

In the genome of Bombyx mori Linnaeus (1758), the microsatellites, or simple sequence repeats (SSR), feature among their particular characteristics a high adenine and thymine (A/T) content, low number of repeats, low frequency, and a grouping in "families" with similar flanking regions. Such characteristics may be the result of a complex interaction between factors that limit the size and dispersion of SSR loci-such as their high association with transposons-and mean that microsatellites within this taxon suitable as molecular markers are relatively rare. The determination of genetic profiles in populations and cell lines has not been affected owing to the high level of polymorphism, nor has the analysis of diversity, structure and genetic relationships. However, the scarcity of suitable microsatellites has restricted their application in genetic mapping, limiting them to preliminary identification of gene location of genes or quantitative trait loci (QTLs) related to thermotolerance, resistance to viruses, pigmentation patterns, body development and the weight of the cocoon, the cortex, the pupa and the filament. The review confirms that, as markers, microsatellites are versatile and perform well. They could thus be useful both to advance research in emerging countries with few resources seeking to promote sericulture in their territories, and to advance in the genetic and molecular knowledge of characteristics of productive and biological interest, given the latest technological developments in terms of the sequencing, identification, isolation and genotyping of SSR loci.