Claudine Dubé

Agronomic characteristics and chemical composition of newly developed day-neutral strawberry lines by Agriculture and Agri-Food Canada.

The agronomic characteristics and chemical composition of seven advanced day-neutral strawberry lines and a commercial cultivar ‘Seascape’ were evaluated for their horticulture and quality attributes. The results showed that the advanced strawberry lines had the best horticultural characteristics, such as more resistance to diseases, less weight and juice losses and better fruit glossiness during storage, compared to ‘Seascape’. Among the advanced lines, FIN005–55 had the better fruit quality with higher soluble solids content (SSC)/titratable acidity (TA) ratio and highest SSC, FIN005–7 had the highest total phenolic content (TPC) and antioxidant capacity (AC), and both had potential for commercial trials.

The effect of three production systems on the postharvest quality and phytochemical composition of Orléans strawberry

Fan, L., Yu, C., Fang, C., Zhang, M., Ranieri, M., Dubé, C. and Khanizadeh, S. 2011. The effect of three production systems on the postharvest quality and phytochemical composition of Orléans strawberry. Can. J. Plant Sci. 91: 403-409. The effects of two production systems, plastic mulch (PM) and plastic mulch with row covers (PMRC) versus the commonly used matted-row system (MRS) on postharvest fruit quality, including shelf life, fruit weight loss and juice leakage, fruit glossiness, postharvest disease caused by grey mould (Botrytis cinerea Pers.), and chemical composition of Orléans strawberry were evaluated during 2008 and 2009. Plastic mulch with row covers accelerated fruit maturity by 7 to 10 d and produced larger fruits compared with the MRS. Production systems significantly changed the total phenolic content (TPC) and total antioxidant content (TAC), but the effect varied during the harvest season. Total phenolic content was significantly higher for PMRC than MRS and PM at early harvest, but the effect was similar to PM at mid and late harvest. Total antioxidant content was significantly higher for PMRC compared with MRS and PM at all stages of fruit production, especially at late harvest. Fruit weight loss and juice leakage and the presence of grey mould during storage were lower and fruit glossiness was higher for those harvested under PMRC compared with those from MRS. No significant differences were observed for firmness, pH, titratable acidity (TA) and soluble solids content (SSC) between the three production systems. Titratable acidity and SSC of PMRC were slightly higher than those from MRS and PM, but the differences were not significant. It seems that PMRC not only accelerates ripening, but also has a significant effect on pre- and postharvest fruit quality and chemical composition of the harvested fruits.

Fruit differential protein patterns in strawberry cultivars susceptible or resistant to grey mould

The total proteins of four strawberry cultivars with differing resistance and/or susceptibility to grey mould were extracted by two different methods, phenol and sodium dodecyl sulphate (SDS). Compared to phenol extraction, SDS extraction produced higher protein yields but poor quality protein bands with a high degree of streaking indicating possible contamination. In contrast, the total proteins obtained by phenol extraction could be used in two-dimensional polyacrylamide gel electrophoresis (2-DE) because of their higher quality, and the protein spots were well separated for all tested genotypes. From all the cultivars studied in this research, we obtained 89 differential (unmatched) protein spots that may be related to fruit disease resistance or susceptibility. Using the SPSS 11.0 software, we obtained a cluster of the four strawberry cultivars. The cultivars “APF029-4” and “SJ8976-1” were in the same subcluster with the highest Pearson correlation coefficient (0.705). Afterwards, they were amalgamated into the second group with “Joliette”, a disease-resistant cultivar, which means that they might have a similar resistance to grey mould.

Changes in ascorbate–glutathione pathway enzymes in response to Mycosphaerella fragariae infection in selected strawberry genotypes

Ten strawberry genotypes, resistant and moderately resistant (Joliette, Seascape, Aromas, FIN005-55 and FIN005-50) and susceptible ones (FIN00132-8, FIN00134-11, FIN00132-14, FIN005-7 and Kent) were used to assess the role of the antioxidative defence system against Mycosphaerella fragariae infection. The pathogen-induced changes of hydrogen peroxide (H2O2) and antioxidant enzymes ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) involved in the ascorbate–glutathione (ASC–GSH) cycle were examined in leaves of the selected genotypes. A significant different response was observed among the genotypes. A marked increase in H2O2 content, APX, MDHAR, DHAR and GR activities were observed in resistant and moderately resistant genotypes after inoculation by M. fragariae. In contrast, weak changes were observed in susceptible genotypes for the aforementioned enzymes and compounds. It seems that resistant genotypes capable of overproducing H2O2 have a higher capacity to scavenge and reduce the injury to strawberry leaves by regulating the ASC–GSH cycle. The results may be useful in future breeding programmes to select those individuals with high scavenging properties to breed new resistant lines.

The Effect of Production Systems on Strawberry Quality

Strawberry with high polyphenols is receiving much more attentions recently. Production systems were reported positive effect on improving crop quality. A complete randomized design with two replicates was employed, and the strawberry selection ‘SJ8976-1’ was planted under three production systems: matted row system (MRS), plastic mulch (PM) and plastic mulch with row covers (PMRC). Total yield, average fruit weight, soluble solids content (SSC), titratable acidity (TA), firmness, fruit postharvest quality, total phenolic content (TPC), total antioxidant content (TAC), oxygen radical absorbance capacity (ORAC) and phenolic composition analysed by high-performance liquid chromatography (HPLC) were evaluated at different harvest times. The results showed that PMRC advanced fruit maturity and improved average fruit weight compared to MRS. SSC, TA and firmness of the strawberry fruits from PMRC were significantly increased at all harvests. Fruit weight loss, juice leakage and presences of grey mould were lower, and fruit glossiness was higher for those harvested under PMRC than those from MRS. TPC, TAC and ORAC of strawberry were significantly changed under different production systems. The phenolic compounds assessed in strawberry were grouped into six major categories, which were anthocyanins, kaempferol, flavonols, hydroxycinnamic acids, ellagic acid and benzoic acids.

Jade crab apple

Khanizadeh, S., Granger, R., Dubé, C. and Groleau, Y. 2013. Jade crab apple. Can. J. Plant Sci. 93: 341-342. Jade is a winter-hardy, scab-resistant ornamental apple tree released by Agriculture and Agri-Food Canada (AAFC), Horticulture Research and Development Centre (HRDC), for Quebec and eastern and central Canada. Its name, ‘Jade’, which is of Spanish origin, is used because of the very shiny light green to yellowish ground colour of the fruits; Jade is named after the first authors daughter.

Javid Crab Apple

Khanizadeh, S., Granger, R., Dubé, C. and Groleau, Y. 2012. Javid Crab Apple. Can. J. Plant Sci. 92: 977-978. Javid is a winter-hardy, scab-resistant ornamental apple tree released by Agriculture and Agri-Food Canada (AAFC), Horticulture Research and Development Centre (HRDC). It is suitable for growing in Quebec and eastern and central Canada. The name ‘Javid’ is derived from the Persian ‘jawid’ meaning eternal, forever, continuous or permanent, due to its fruit persistency after ripening, and is named after the first authors son.