SummaryAdvances in elucidating the molecular processes controlling flower initiation and development have provided unique opportunities to investigate the developmental genetics of non-flowering plants. In addition to providing insights into the evolutionary aspects of seed plants, identification of genes regulating reproductive organ development in gymnosperms could help determine the level of homology with current models of flower induction and floral organ identity. Based upon this, we have searched for putative developmental regulators in conifers with amino acid sequence homology to MADS-box genes. PCR cloning using degenerate primers targeted to the MADS-box domain revealed the presence of over 27 MADS-box genes within black spruce (Picea mariana), including several with extensive homology to either AP1 or AGAMOUS, both known to regulate flower development in Arabidopsis. This
Studies were conducted under laboratory conditions to document the potential of Beauveria bassiana conidia applications for controlling the white pine weevil, Pissodes strobi (Peck). A screening test including six B. bassiana isolates allowed us to demonstrate that CFL (Centre de Foresterie des Laurentides) and IP-CPB (Iˆle Perraultcharanc¸on du pin blanc) were the most virulent isolates among the ones tested, with percentages of mortality after 3 weeks of 73% and 85.5%, respectively. These two B. basiana isolates were applied either onto soil or branch sections to compare the effectiveness of these potential control strategies. Greater than 75% mortality was observed within 3 weeks for both modes of application using suspensions of B. bassiana at a concentration of 1.0 · 10 8 (soil application) and 1.0 · 10 9 conidia/ml (branch application). The results demonstrate for the first time that B. bassiana is an effective entomopathogen against P. strobi.
In 2009 unusual white pine needle discoloration was observed in eastern Canada and northeastern USA. While the symptoms were similar in most pine stands, the disease was diagnosed as Canavirgella banfieldii in several locations and Dooks needle blight caused by Lophophacidium dooksii in others. Because of the similarities in symptom development and morphological characters of the causal agents, it was suspected that C. banfieldii and L. dooksii are either the same or closely related species. To test this hypothesis we examined several collections representing C. banfieldii and L. dooksii, including the two type specimens. Phylogenetic analyses of nuc internal transcribed spacer rDNA sequences confirm the synonymy of C. banfieldii with the earlier described L. dooksii and provide the first evidence of the close evolutionary relationship of L. dooksii to other pine pathogens.
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