Nitric oxide in combination with indole-3-butyric acid improves root growth in ‘Ferdor Julior’ hardwood cuttings (Prunus insistitia (L.) × Prunus domestica (L.))

The production of plants for high density fruit orchards requires a highly efficient clonal propagation method. ‘Ferdor Julior’ rootstock is well adapted to different soil conditions, but its natural rooting potential is very limited. Propagation treatments, such as bottom heat and indole-3-butyric acid (IBA) applications have previously been used to improve rooting. The aim of this work is to evaluate the effects of either IBA, or sodium nitroprusside (SNP; a nitric oxide (NO) donor), or a combination of both on the rooting of hardwood cuttings of ‘Ferdor Julior’. As metabolism markers, ascorbic acid (AA) and glutathione (GSH) were measured in adventitious roots. ‘Ferdor Julior’ hardwood cuttings were treated as follows: untreated, 0.3 mM IBA, 1 mM SNP, 1 mM SNP previously exposed to light (as a negative control), and 1 mM SNP + 0.3 mM IBA. After 4 months, the combined use of SNP and IBA had increased root growth and lateral rooting, but resulted in less shoot growth, whilst AA and GSH concentrations were also reduced. IBA and SNP individual treatments showed intermediate results, compared to untreated cuttings. According to the results obtained, there may be an additive effect of auxin and NO signaling pathways. In conclusion, this new and promising technique for ‘Ferdor Julior’ propagation could improve lateral root development and promote early lateral root growth.     

Drought responses of an exotic tree (Eriobotrya japonica) in a tropical cloud forest suggest the potential to become an invasive species

New Forests - Eriobotrya japonica is a non-native tree expanding in secondary forests and threatening the tropical montane cloud forest of central Veracruz, Mexico. Our objective was to investigate...     

Assessment of the bacterial community diversity associated with the queen conch Strombus gigas (Linnaeus, 1758) from the Caribbean coast of Colombia using denaturing gradient gel electrophoresis and culturing

The biotic diversity of Strombus gigas has not been thoroughly studied despite the status of the queen conch as an important ecological resource. The bacteria associated with the conch influence their host in several ways, including through the metabolism of nutrients, protection against invasive bacteria and the regulation of the physical conditions. In this study, conventional microbiological methods and molecular tools such as denaturing gradient gel electrophoresis (DGGE) were used to assess the composition of the bacterial communities associated with the queen conch (S. gigas) in wild and captive habitats in Colombia. A genetic analysis of the bacterial communities revealed a high level of diversity based on the large number of bands detected using DGGE. In addition, differences in bacterial community structure were found between the conchs in captivity and the wild populations. The dominant phylogenetic affiliations of the bacteria, as determined using 16S rRNA gene sequencing, were grouped into four classes, namely, Betaproteobacteria (16%), Gammaproteobacteria (70%), Firmicutes (7%) and Actinobacteria (2%). These groups are related to host defence processes and the decomposition of organic matter. The 16S rDNA sequence analysis of the cultured bacteria and the resulting DGGE profiles are useful tools for characterizing the diversity of the bacteria associated with the analyzed conchs.