|Susceptibility of selected strawberry lines to fruit deformation
Nader Koohpayehzadeh1, Guy Boivin2, Yves Desjardins1, Shahrokh Khanizadeh2
1 Department of Phytology, Laval University, Quebec, Canada; 2 Agriculture and Agri-Food Canada, CRDH, Saint-Jean-sur-Richelieu, Quebec, Canada
Incomplete pollination and insect damage, mostly by plant bugs (Miridae), cause fruit deformation in the strawberry, Fragaria x ananassa Duchesne. Insect feeding and oviposition damage achenes and cause reduction in fruit size and marketable yield. While fruit malformation by mirid bugs has been studied in several strawberry cultivars, few data are available on the effect of incomplete pollination on strawberry yield. In 2006 and 2007, a field experiment was set up using a completely randomized block design to examine fruit deformation, caused by incomplete pollination, in 8 June-bearing (JB) and 7 day-neutral (DN) strawberry genotypes. In 2007, maximum (12.2%) and minimum (4%) yield damages were observed on FIO9313-70 and Honeoye, two JB genotypes, respectively. A different level of damage was observed on DN genotypes with 19.8%, 10.2% and 6% respectively for Rosalyne, FIN005-55 and Aromas. In 2006, the highest yield damages in DN strawberries was for Fort Laramie (22.6%) and Rosalyne (21.1%) and it was the lowest for Seascape (9%) and FIN008-124 (6.7%). A high level of fruit deformation observed in all JB genotypes in 2006 and yield damages were not significantly different (p<0.05) between these genotypes. It was interesting to note that Rosalyne a DN ornamental strawberry with abundant and large number of flowers showed significatively (p<0.05) the highest incomplete pollination in both years. Incomplete pollination in these strawberry genotypes might be due to pistil sterility, low density or viability of pollens and poor activity of insect pollinators on these cultivars. Our results can be used in plant breeding programs to develop strawberry cultivars with the lowest proportion of incomplete pollination and the highest well shaped berries.