Epi fl filter block n uv 2a

Decolorized aniline blue (DAB; 0.1 % w/v) was used to detect the presence of callose in the ovules, as described by Martin (1959 (link)). Individual flowers were dissected from fixed capitula, transferred to 80 % ethanol for 30 min, pretreated with 1 N NaOH for 4 h at 37 °C, and after three washes with distilled water and one with 0.1 M K₃PO₄, the softened samples were stained overnight in 0.1 % DAB in 0.1 M K₃PO₄ at room temperature. Then the flowers were placed into a drop of 0.1 M K₃PO₄:glycerol (1:1, v/v) on a microscope slide and ovules were dissected under a stereomicroscope. After ovule isolation, samples were gently squashed under a cover slip and observed under UV light using a Nikon Eclipse E400 microscope with an Epi-Fl Filter Block N UV-2A consisting of excitation filter EX330–380, dichroic mirror DM400, and barrier filter BA420. A total of 247 ovules were analyzed; 146 ovules of T. linearisquameum and 101 ovules of T. atricapillum (Table 1).

Decolorized aniline blue (DAB; 0.1 % w/v) was used to detect the presence of callose (Martin 1959 (link)). Individual flowers were dissected from fixed capitula and transferred to 80 % ethanol for 30 min. Then they were softened in 1 N NaOH for 4 h at 37 °C, and after three washes with distilled water and one with 0.1 M K₃PO₄, the softened samples were stained overnight in 0.1 % DAB in 0.1 M K₃PO₄ at room temperature. After washing with 0.1 M K₃PO₄, flowers were placed into a drop of 0.1 M K₃PO₄/glycerol (1:1, v/v) on a microscope slide and ovules were dissected under a stereomicroscope. After ovule isolation, samples were gently squashed under a cover slip and observed under UV light using a Nikon Eclipse E400 microscope with an Epi-Fl Filter Block N UV-2A consisting of excitation filter EX330–380, dichroic mirror DM400, and barrier filter BA420. A total of 146 ovules were analyzed.

The procedure for preparing the plant material was as previously described by Musiał and Kościńska-Pająk (2017 (link), 2019 (link)). Florets were isolated from capitula and placed in 80 % ethanol for 1 h. Then the plant material was softened in 1 N NaOH at 37 °C for 4 h. Samples were rinsed with distilled water three times and once with 0.1 M K₃PO₄, stained overnight at room temperature with decolorized aniline blue (DAB; 0.1 % w/v). After rinsing with 0.1 M K₃PO₄, florets were placed on a microscope slide in a drop of K₃PO₄ mixed with a drop of glycerol. Subsequently, the ovules were isolated from ovaries and squashed under a cover slip. The samples were observed under UV light using a Nikon Eclipse E400 microscope fitted with an Epi-Fl Filter Block N UV-2 A which consists of an excitation filter EX330–380, a dichroic mirror DM400 and a barrier filter BA420.