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The objective of this work was to obtain high‐yielding F1 hybrids of the habanero pepper, using 10 outstanding parents in a line‐tester genetic design. General combinatorial ability and specific combinatorial ability were evaluated in the parents' and the hybrids F1 obtained, respectively. Heterosis was determined in the 18 hybrids obtained. The technique of HPLC was used to evaluate the capsaicin content in the fruit of 10 parents and 18 hybrids of habanero pepper. The DNA profiles were analysed as part of the characterization of the germplasm of the species conserved at the CICY. Furthermore, the molecular variation of the genotypes under investigation was assessed using eight SSR and nine ISSR markers. The results showed the presence of substantial morphoagronomic and molecular variability among the habanero pepper genotypes evaluated. Genetic similarities of 83%–93% between parents and 76%–94% between hybrids were found. The most productive hybrids were H8, H10 and H19 with 3.13 to 4.29 kg/plant, respectively, these came from crosses where RNJ‐04 (P26) as the male parent and the hybrid H60 (4.92 kg/plant) that comes from the male parent RES‐08 (P30). Likewise, the H7 hybrid had the highest capsaicin content (128.41 mg/g dry weight, 960,687.00 SHU). Hybrids H43 with 114.39 mg/g DW and 90,444.30 SHU, and H51 with 11.61 mg/g DW and 934,745.07 SHU respectively, also stood out. [ABSTRACT FROM AUTHOR]

Oil palm (Elaeis guineensis Jacq.) has become the largest source of vegetable oil in the world. It is known that all existing genotypes of this species are related, so their genetic variability is considered to be low. In Mexico, all oil palm plantations are located in the southeast of the country, and they are established with different origins seeds, which has caused poor yields and resulted in the need to establish a genetic improvement program. Therefore, in this study, the extent of genetic diversity among 151 oil palm accessions from all producing regions of Mexico was assessed with twenty simple sequence repeats (SSRs) and seven random amplified microsatellite (RAM) markers. The markers utilized proved to be useful in revealing high existing genetic variability, with a total of 1218 and 708 alleles detected and polymorphic information content (PIC) of 0.96 and 0.91 for RAM and SSR, respectively. The genetic distance among all accessions of oil palm collected ranged between 31% and 82% for similarity. Accessions from Tabasco and Veracruz presented the greatest and smallest genetic diversity, respectively. These results can allow breeding strategies to be established for the genetic improvement of this crop in Mexico. [ABSTRACT FROM AUTHOR]

Selection of lines from segregating generations and breeding hybrids to exploit heterosis or heterobeltiosis is an effective tool for improving economically important traits in the genus Capsicum. The objective of this study was to identify high potential parents to obtain high-yielding F1 hybrids using a Line × Tester (8 × 2) mating design in the Habanero pepper improvement programme. Ten parents and 16 hybrids were evaluated in order to determine their values of general combining ability, specific combining ability, heterosis, and heterobeltiosis. Parent NKA-11 had the highest values of GCA for different quantitative variables of the fruit, which does it suitable for future improvement works, and tester RNJ-04 showed the highest value of GCA for fruit length. The quantitative variables evaluated confirm a significant genetic variability among the Habanero pepper genotypes studied. The best hybrids were NEK-03xRNJ-04, NBA-06xRNJ-04, AKN-07xRNJ-04, and RKI-10xRNJ-04, which showed their high productive potential with values between 3.13 and 4.92 Kg/Pta, a quality, that would open to them the national market for fresh consumption. Based on the GCA values of the parents and heterosis of the progenies, it is concluded hybridization would be the most appropriate genetic improvement method to increase both yield (YP) and the number of fruits for plant. [ABSTRACT FROM AUTHOR]

In this study, three commercial botanical acaricides (BA) were evaluated on two species of phytophagous mites, the red palm mite (Raiella indica) and the papaya mite (Oligonychus sp.). The toxicity of the BA on the predatory mites Neoseiulus californicus and Phytoseiulus persimilis was also assessed. For R. indica, CinnAcar and EPA-90 caused more than 90% decrease in the population density in the laboratory. In field trial, CinnAcar was the most effective in suppressing the mite population density. For Oligonychus sp., CinnAcar and EPA-90 caused up to 88.5 and 95.2% mortality in the laboratory. In greenhouse trial, EPA-90 caused more than 90% decrease in the population density of motile stages. Residual exposure showed that EPA-90 had moderate toxicity to the phytoseiid predators, causing 48% mortality in N. californicus and 55% mortality in P. persimilis, whereas CinnAcar and NeemAcar produced 22 to 32% mortality. [ABSTRACT FROM AUTHOR]

A total of 24 extracts (aqueous and ethanolic) from nine plant species were evaluated against Alternaria chrysanthemi, the causal agent of leaf spot of chrysanthemum. The highest antifungal activity was shown by ethanolic and aqueous extracts of Acalypha gaumeri root (Growth inhibition, GI = 75 and 69%, respectively), and by the aqueous extracts of Bonellia flammea stem and leaf (GI = 63 and 50%, respectively). These active extracts were subsequently assessed by agar dilution assay, where ethanolic extract (EE) of A. gaumeri root caused the highest inhibition of mycelial growth and sporulation, with a median Inhibitory Concentration (IC50) of 0.53 mg/mL against A. chrysanthemi GI. This extract was partitioned and the highest activity was observed in the medium polarity fraction (ACR-1E), where an IC50 of 0.13 mg/mL was recorded. This fraction completely inhibited A. chrysanthemi infection in chrysanthemum leaf, at concentrations of 85µg/cm². Also, A. gaumeri extract was able to inhibit the fungal strains Alternaria sp. (ITC02), Colletotrichum capsici, Colletotrichum gloeosporioides, Corynespora cassiicola, Curvularia sp. (ITC10), and Helminthosporium sp. (ITC04). The EE of A. gaumeri root may be a potential source of botanical fungicide to control phytopathogens. [ABSTRACT FROM AUTHOR]

During 2010 in Nopaltepec, Mexico, cactus plants were detected with symptoms of distortion and thickening of the cladode, mosaic, yellowing, proliferation and deformation of fruits in the whole plant or part of it. Since the syndrome has been attributed to phytoplasma infection, the objective of this study was to detect, the presence of phytoplasmas in different strata of the cladode and the roots of cactus plants by Polimerase Chain Reaction (PCR). The DNA extracted from cladodes with symptoms and asymptomatic, was amplified firstly with universal primers P1/P7, and P1/Tint, fragment of phytoplasma 16S rRNA gene, followed by nested PCR using the primers R16F2/R16R2, a fragment of 1 200 bp was obtained. Analysis of restriction patterns generated with endonucleases revealed that the phytoplasma belongs to the Mexican periwinkle virescence-16SrXIII. [ABSTRACT FROM AUTHOR]

An aluminium (Al)-tolerant cell line (LAMt) of coffee (Coffea arabica L.) was obtained from a cell suspension culture and biochemically and molecularly characterized in an MS medium at half ionic strength and low pH. LAMt grew 30% more than the control line (susceptible to Al) in the presence of different concentrations of Al, showed a lower free Al concentration in the medium and had higher phospholipase C specific activity (80%). Membrane integrity of the LAMt was 50% greater than the control line when both were incubated in the presence of different Al concentrations (measured by Evans Blue uptake). Finally, the use of microsatellite primers revealed no difference in the DNA pattern of both cell lines.