Pedigree and mating system analyses in a western larch (Larix occidentalis Nutt.) experimental population

?The mating pattern and gene flow in a western larch (Larix occidentalis Nutt.) experimental population was studied with the aid of microsatellite markers and a combination of paternity-mating system analysis. The commonly difficult to assess, male gametic contribution was determined with 95% confidence and its impact on genetic gain and diversity was determined.

? Male fertility success rate ranged between 0 and 11%. Male reproductive output parental imbalance was observed with 50% of the pollen being produced by the top 5% of males while the lower 39% males only produced 10% of the pollen.

? A significant difference was observed between male effective population size (genetic diversity) estimates from paternity assignment compared to those based on population’s census number (21 vs. 41); however, this difference did not affect estimates of genetic gain.

? A total of 221 full-fib families were identified (sample size range: 1–8) and were nested among the studied 14 seed-donors.

? A combination of paternity-mating system analysis is recommended to provide a better insight into seed orchards’ mating dynamics. While pollen flow tends to inflate mating system’s outcrossing rate, the paternity analysis effectively determined the rate and magnitude of contamination across receptive females.

     

Fabrication of electrospun antimicrobial nanofibers containing metronidazole using nanospider technology

Nanospider technology as a modified electrospinning technique was used for the fabrication of electrospun nanofibers based on poly(vinyl alcohol) (PVA)/poly(ethylene oxide) (PEO) blend as drug delivery system (DDS) for metronidazole (MTZ) as an antimicrobial drug. Electrospun PVA/PEO/MTZ composite nanofibers were stabilized against disintegration in water by heating in oven at 110°C, or by soaking in isopropyl alcohol for 6 hrs. Incorporation of MTZ into electrospun nanofibers was confirmed by SEM, FT-IR spectra and TGA. The drug release results showed that the burst release was suppressed with stabilized electrospun nanofibers compared with non-stabilized ones. Electrospun PVA/PEO/MTZ composite nanofibers exhibited remarkable antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger, Penicillium notatum and Aspergillus flavus which varies with the species of the tested organisms.