Spray Nozzles,Pressures, Additives and Stirring Time on Viability and Pathogenicity of Entomopathogenic Nematodes (Nematoda: Rhabditida) for Greenhouses

The objective of this study was to evaluate different strategies for the application of entomopathogenic nematodes (EPN). Three different models of spray nozzles with air induction (AI 11003, TTI 11003 and AD-IA 11004), three spray pressures (207, 413 and 720 kPa), four different additives for tank mixtures (cane molasses, mineral oil, vegetable oil and glycerin) and the influence of tank mixture stirring time were all evaluated for their effect on EPN (Steinernema feltiae) viability and pathogenicity. The different nozzles, at pressures of up to 620 kPa, were found to be compatible with S. feltiae. Vegetable oil, mineral oil and molasses were found to be compatible adjuvants for S. feltiae, and stirring in a motorized backpack sprayer for 30 minutes did not impact the viability or pathogenicity of this nematode. Appropriate techniques for the application of nematodes with backpack sprayers are discussed.     

Hepatocellular carcinoma in two captive golden‐headed lion tamarins (Leontopithecus chrysomelas)

Two cases of hepatocellular carcinoma (HCC) in 2 female captive golden‐headed lion tamarins (Leontopithecus chrysomelas) are described. HCC was diagnosed in both, with pulmonary metastasis in one of them. Neoplastic cells were positive for hepatocyte‐specific antigen (HSA) by immunohistochemistry, confirming the diagnosis.     

Periphyton nutrient content,biomass and algal community on artificial substrate: response to experimental nutrient enrichment and the effect of its interruption in a tropical reservoir

Periphyton plays an important functional role in the retention of nutrients in aquatic ecosystems, especially phosphorus. We evaluated the effects of enrichment with N and P and the effect after 20 days of no additional N and P on periphyton on artificial substratum in open-bottom mesocosms. The aim was to jointly evaluate periphyton, phytoplankton and zooplankton in the presence of macrophytes. Experimental conditions simulated natural conditions and nutrient addition was based on the maximum concentration recorded in mesotrophic reservoir. Our hypothesis is that the periphyton is sensitive to the effects of N and P enrichment and its interruption, despite the positive response of phytoplankton and zooplankton. Two treatments were designed using open-bottom mesocosms (n = 3): control (no nutrient addition); NP+ (combined phosphorus and nitrogen addition). Sampling for the measurement of biotic and abiotic variables was performed, with 10 days of continuous enrichment, on the 3rd, 6th and 11th, and 20 days after enrichment had ended (31st day). Periphyton chlorophyll a, dry mass and algal density increased significantly with the addition of N and P and decreased 20 days after the interruption of the enrichment. The highest periphyton P content was found in the NP+ treatment. The enrichment had a positive effect on Chrysophyceae (Chromulina spp.) and rotifer (Polyarthra spp.) density and the interruption of enrichment favored Bacillariophyceae (Gomphonema sp.) and rotifers (Gastropus stylifer). Phytoplankton responded positively to enrichment. Along with the high macrophyte coverage over the experimental period, we evidenced the positive effect enrichment had on phytoplankton biomass and zooplankton abundance. Therefore, periphyton on artificial substrate was sensitive to effects of N and P enrichment and its interruption, responding promptly to changes in nutrient availability in a scenario of high competition and grazing.     

Impact of long‐term chromosomal shuffling on the multispecies coalescent analysis of two anthropoid primate lineages

Multispecies coalescent (MSC) theory assumes that gene trees inferred from individual loci are independent trials of the MSC process. As genes might be physically close in syntenic associations spanning along chromosome regions, these assumptions might be flawed in evolutionary lineages with substantial karyotypic shuffling. Neotropical primates (NP) represent an ideal case for assessing the performance of MSC methods in such scenarios because chromosome diploid number varies significantly in this lineage. To this end, we investigated the effect of sequence length on the theoretical expectations of MSC model, as well as the results of coalescent‐based tree inference methods. This was carried out by comparing NP with hominids, a lineage in which chromosome macrostructure has been stable for at least 15 million years. We found that departure from the MSC model in Neotropical primates decreased with smaller sequence fragments, where sites sharing the same evolutionary history were more frequently found than in longer fragments. This scenario probably resulted from extensive karyotypic rearrangement occurring during the radiation of NP, contrary to the comparatively stable chromosome evolution in hominids.     

Diversity and evolution of rice progenitors in Australia

In the thousands of years of rice domestication in Asia, many useful genes have been lost from the gene pool. Wild rice is a key source of diversity for domesticated rice. Genome sequencing has suggested that the wild rice populations in northern Australia may include novel taxa, within the AA genome group of close (interfertile) wild relatives of domesticated rice that have evolved independently due to geographic separation and been isolated from the loss of diversity associated with gene flow from the large populations of domesticated rice in Asia. Australian wild rice was collected from 27 sites from Townsville to the northern tip of Cape York. Whole chloroplast genome sequences and 4,555 nuclear gene sequences (more than 8 Mbp) were used to explore genetic relationships between these populations and other wild and domesticated rices. Analysis of the chloroplast and nuclear data showed very clear evidence of distinctness from other AA genome Oryza species with significant divergence between Australian populations. Phylogenetic analysis suggested the Australian populations represent the earliest‐branching AA genome lineages and may be critical resources for global rice food security. Nuclear genome analysis demonstrated that the diverse O. meridionalis populations were sister to all other AA genome taxa while the Australian O. rufipogon‐like populations were associated with the clade that included domesticated rice. Populations of apparent hybrids between the taxa were also identified suggesting ongoing dynamic evolution of wild rice in Australia. These introgressions model events similar to those likely to have been involved in the domestication of rice.