Medium-Genotype-Interaction on Androgenetic Haploid Production in Wheat

The present study investigates the effects of media on the rate of green plantlet formation from anther cultures of five different winter and spring wheat cultivars. An increased number of embryos and calli were produced on Ficoll-containing liquid potato-2 medium, whereas the addition of 0.2 M/l maltose increased the rate of regeneration. The genotypes had strong effect on the formation of plantlets, but the developed procedure allows also the regeneration of recalcitrant genotypes. On the best medium sequence, a total of 2430 anthers over all genotypes were plated which developed 1325 macroscopic structures (55 %) of which 159 green plants have developed, i.e. 12 % from the structures and 7 % from the plated anthers, respectively.     

Grapevine trunk diseases: complex and still poorly understood

This review presents an overview of eutypa dieback, esca and botryosphaeria dieback, the predominant grapevine trunk diseases worldwide. It covers their symptomatologies in the trunk, leaves and berries; the characteristics of the different fungal species associated with them; and host–pathogen interactions. Here, the host–pathogen relationship is defined at the cytological, physiological and molecular levels. Currently available experimental tools for studying these diseases, both in vitro and in the field, are discussed. Finally, a progress report on their control, which, since the ban of sodium arsenite, comprises chemical, biological and/or sanitation methods, is presented.     

Morphological characterization of Arctic char, Salvelinus alpinus, eggs subjected to rapid post-ovulatory aging at 7 °C

Egg quality in Arctic char, Salvelinus alpinus, kept indoors at 7 °C during spawning season was morphologically classified. Four egg categories based on lipid droplet distributions and egg diameter were characterized. Eggs with homogenous lipid vesicle distributions and a uniform size were classified as Good. Eggs with some yolk lipid droplets coalesced toward one pole but were homogeneous in size were classified as Fair. Eggs with lipid vesicles that were usually coalesced at one or two poles with were classified as Poor. The fourth egg category was Heterogeneous, in which lipid vesicle distribution and egg size were inhomogeneous. This distribution pattern of the lipid vesicle had a strong relationship with the percentage of fertilized and eyed eggs. Percentages of fertilized and eyed eggs in Good and Fair eggs were 85.5 and 83.4; 30.2 and 28.2, respectively. With Poor and Heterogeneous eggs, the percentages of fertilized and eyed eggs were zero. Egg diameter and absolute weight was increased in Poor eggs than in other egg categories. Relative weight increase during hardening after 30, 45 and 60 min were higher in Good and Fair eggs than in Poor and Heterogeneous eggs. Ovarian fluid collected from egg batches with low rates of fertilized and eyed eggs (Heterogeneous and Poor) had a lower pH and higher protein and aspartate amino-transferase enzyme than ovarian fluid from eggs batches classified as Good or Fair, while the ovarian fluid osmolality did not significantly differ. ATP contents of Poor and Heterogeneous eggs were lower than for Good and Fair eggs. In Heterogeneous eggs, both ATP and acid phosphatase contents were very variable.