Levels of genetic variation and genetic structure of 15 wild populations and three domesticated populations of Capsicum annuum were studied by RAPD markers. A total of 166 bands (all of them polymorphic) and 126 bands (125 of them polymorphic) were amplified in wild and domesticated populations, respectively. Mean percentage of polymorphism was 34.2% in wild populations and 34.7% in domesticated populations. Mean and total genetic diversity were 0.069 and 0.165 for wild populations and 0.081 and 0.131 for domesticated populations. Parameters of genetic diversity estimated from 54 bands with frequencies ‡1 À (3/n) (n = sample size) showed that 56.7% of the total variation was within and 43.3% among wild populations, whereas 67.8% of the variation was within and 32.2% among domesticated populations. AMOVA indicated that total genetic diversity was equally distributed within (48.9 and 50.0%) and among (50.0 and 51.1%) populations in both wild and domesticated samples. Wild and domesticated populations were clearly resolved in a UPGMA dendrogram constructed from Jaccard's distances (average GD = 0.197), as well as by AMOVA (17.2% of variance among populations types, p = 0.001) and by multidimensional scaling analysis. Such differentiation can be associated with domestication as well as different origin of gene pools of the wild (Northwestern Mexico) and cultivated (more probably Central Mexico) samples analyzed. The considerable genetic distances among cultivars (average GD = 0.254) as well as the high number of diagnostic bands per cultivar (33 out of 126 bands), suggest that genetic changes associated with domestication could have resulted from artificial selection intervening in different directions, but the inclusion of more domesticated samples might clarify the nature of distinctions detected here.

The anaiysis of the variability and genetic structure of wild and landrace populations of pepper {Capsicum annuum L.) is important for the management and conservation of valuable genetic resources and to understand the consequences cf domestication on the patterns of neutral genetic variation. For this purpose, 12 popuiations of wild peppers, 3 landrace populations and 7 hybrid populations from northwestern Mexico were studied using microsateliites. On average, 3.62 alíeles per locus were detected in the wild relatives, 3.37 in the landraces, and 3.08 in the hybrids. According to the average vaiues of expected heterozygosity (He), slightly greater genetic diversity was found among the wild relatives (He = 0.466) than in the hybrids (He = 0.440) or the landraces (He = 0.422). In terms of the average number of alíeles per locus and the average expected heterozygosity, reductions of 8.18 and 10.25% were found in the genetic diversity of the landraces and hybrids, respectively, with respect to the wild populations. The genetic differentiation among the populations was the highest among hybrids (Gg.^ = 0.324), followed by landraces (0.309) and wild relatives (the lowest, at 0.208). Cluster analysis clearly demarcated the wild relatives and domesticated populations into different groups. The high levels of genetic diversity found among C. annuum in northwestern Mexico suggest that the wild and landrace populations are a valuable resource that should be conserved.

Altitudinal clines in body size can result from the effects of natural and sexual selection on growth rates and developing times in seasonal environments. Short growing and reproductive seasons constrain the body size that adults can attain and their reproductive success. Little is known about the effects of altitudinal climatic variation on the diversification of Neotropical insects. In central Mexico, in addition to altitude, highly heterogeneous topography generates diverse climates that can occur even at the same latitude. Altitudinal variation and heterogeneous topography open an opportunity to test the relative impact of climatic variation on body size adaptations. In this study, we investigated the relationship between altitudinal climatic variation and body size, and the divergence rates of sexual size dimorphism (SSD) in Neotropical grasshoppers of the genus Sphenarium using a phylogenetic comparative approach. In order to distinguish the relative impact of natural and sexual selection on the diversification of the group, we also tracked the altitudinal distribution of the species and trends of both body size and SSD on the phylogeny of Sphenarium. The correlative evidence suggests no relationship between altitude and body size. However, larger species were associated with places having a warmer winter season in which the temporal window for development and reproduction can be longer. Nonetheless, the largest species were also associated with highly seasonal environments. Moreover, large body size and high levels of SSD have evolved independently several times throughout the history of the group and male body size has experienced a greater evolutionary divergence than females. These lines of evidence suggest that natural selection, associated with seasonality and sexual selection, on maturation time and body size could have enhanced the diversification of this insect group.

The Broad autism phenotype (BAP) refers to a set of subclinical behavioural characteristics qualitatively similar to those presented in Autism spectrum disorders (ASDs). The BAP questionnaire (BAPQ) has been widely used to assess the BAP both in relatives of ASD people and within the general population. The current study presents the first Spanish version of the BAPQ (BAPQ-SP) and analyses its psychometric properties, including validity evidences based on the BAPQ scores relationship with other variables. Our results only support the use of the Aloof and Rigid sub-scales to assess this phenotype, whereas Pragmatic Language sub-scale seems to be the main source of misfit. This research represents a first step in the study of the BAP features in the Spanish population.

Fertilizer application enable producers to influence pasture production. The effect of N fertilization on grass production and leguminous plant content of pasture and strategic N application has received much attention. Changing agricultural policies suggest that chemical fertilizer inputs may be diminished and that alternative sources of nutrients are desired. The aim of this study was to evaluate the effect of N and K fertilization on production, botanical composition, and forage mineral composition to gain some insight into what influence changing fertilization practices would have on pasture productivity. Three K and 3 N application rates were applied in a factorial design on a white clover ( Trifolium repens L.) perennial ryegrass (Lolium perenne L.) sward. Potassium and nitrogen application increased herbage production and had differential influences on botanical composition. Nitrogen decreased clover content in the pasture, whereas K increased the proportion and production of white clover. The effects of K application appeared later in the experiment than those associated with N. We concluded that K is very important for development and maintenance of white clover in pasture, which increases herbage and protein production.Nitrogen was associated with lesser amounts of N, P, K, and Mg in pasture, because of lesser amounts of clover in the sward.Changing fertilization practices will have definite influences on sward composition and pasture productivity. Any interpretation of pasture mineral content should take botanical composition changes into account.