**3. Crossing methods, seed germination and testing of self-pollination**

I performed emasculation under magnification glasses in unopened flower-buds. The emasculated flowers were isolated in glassine crossing bags. Unopened flowers of the pollen parents were usually isolated in glassine crossing bags in advance to eliminated contaminating pollen. Such isolated flowers at the anthesis were directly used for pollination after the emasculated seed parent flowers were checked for the absence of anthers under magnification.

Cleaned mature seeds (achenes) were usually germinated on agar gel, where axenic conditions were tried to be attained. The seeds were surface sterilized with 0.001% HgCl2 in water in tubes for 20 min, at times vortexed, rinsed with two changes of sterile water, and placed individually on sterile 1% gel of Bacto-agar (Difco, Detroit, USA) made in tap-water, with added 0.01% CaCO3. After germination, the seedlings with one or two vegetative leaves were transferred to soil (**Figure 5**). The commercial organic growing soil Puutarhan Musta multa (Biolan, Eura, Finland) was usually used

#### **Figure 5.**

*Axenic germination of hybrid seeds of* Fragaria moschata *'Kotka'* F*.* viridis *on water agar gel. The germinats are at a suitable size to be transferred to soil. Scale digits millimeters.*

for growing. The experimental cultivation was mostly done in Kirkkonummi Municipality, on the southern coast of Finland.

Inflorescences before the opening of the flower buds were isolated in glassine crossing bags to test the self-pollination ability of the flowers. If the earliest flowers had already opened, they were removed before the isolation. Crossing bags were cut to a suitable length, closed around the inflorescence stem with a paper-clip, and were often needed to be tied with a thread to a bamboo-stick for support. The opened flowers were also scored for the sex organs once or twice during the flowering period.
