Improved technique for treating seed dormancy to enhance germination in Rosa × hybrida

Rose breeders need reliable and efficient germination protocols to exploit all viable embryos in their breeding programs. In this study, different treatment combinations were assessed to overcome the mechanical resistance of the pericarp and enhance germination of rose seeds obtained from hybridisation among hybrids roses. In the 3 treatments, 30 days of a warm temperature followed by 60 days of cold stratification and 30% sulphuric acid treatment for 10 min proved more effective in getting higher seed germination (18.54%) and seed vigour index (261.18) of the progenies. This led to lower germination (18.20 days) and imbibition (23.64) periods with respect to the other 3 treatments including the control. This treatment also helped increase the total length of progeny (14.1 cm) and number of leaves per progeny (6.44), whereas the response of other growth parameters of progeny was variable to this treatment. Correlation (r) between pericarp thickness and seed germination percentage, germination period, and imbibition period proved highly significant (r = 0.347, P < 0.05).