Germination of Pulsatilla Seeds as Influenced by Seed Morphology, Moist 5 °C and Gibberellin (GA3) Treatment, and Detection of Nickel in Seeds

Abstract

<jats:p>Seeds of <jats:italic>Pulsatilla turczaninovii</jats:italic> were categorized to full and empty seeds based on observations under a light microscope and on X-ray images. A germination test for full or empty seeds was evaluated as affected by the duration of gibberellin GA<jats:sub>3</jats:sub> and the moist 5 °C cold stratification (CS) treatment. The morphological and elemental components of <jats:italic>P. turczaninovii</jats:italic> and <jats:italic>P. cernua</jats:italic> var. <jats:italic>koreana</jats:italic> seeds were analyzed using low-temperature scanning electron microscopy (LT-SEM) and energy dispersive X-ray diffraction analysis. The results showed that 64% of full and semifull <jats:italic>P. turczaninovii</jats:italic> seeds 10 weeks after harvesting germinated in 17 to 19 days; however, the germination rate, including empty and semiempty seeds, was lower (52.6%). Full seeds with damaged or dried vegetative organs (embryo or endosperm) and semifull seeds with severely damaged vegetative organs were observed, and this result could be related to low germination rates. Germination patterns of seeds stored dry at 5 °C for 44 weeks that showed a sigmoid pattern were increased by immersing seeds in a GA<jats:sub>3</jats:sub> solution for 8 hours and treating seeds with 16 or 32 days of CS. More seeds germinated between 12 and 17 days (as compared with 17 to 29 days), especially when they were treated with GA<jats:sub>3</jats:sub> and received 32 days of CS. Comparison of germination rates of visually full seeds upon harvest (52.6%) with those that had been stored dry for 44 weeks (26.3% to 29.7%) suggested that the viability of seeds may have decreased. Dormancy could be a factor that decreased germination and can be removed by low temperature and GA<jats:sub>3</jats:sub> treatment. LT-SEM revealed a valley-like, sunken streak in empty seeds of <jats:italic>P. cernua</jats:italic> var. <jats:italic>koreana</jats:italic>. The nickel content in the trichome and seedcoat of full and empty seeds of both taxa ranged from 2.98 to 4.62 (weight %), as determined on X-ray images. Our study suggested that the low germination rate was due to either the presence of dormancy, damage to either embryo or endosperm, a loss in viability, or the presence of nickel in the seeds.</jats:p>

Propagation in Vitro and Experimental Field Cultivation ex Situ of Pulsatilla Turczaninovii Kryl. et Serg. (Ranunculaceae)

“…Visually full seeds upon harvest germinated in 52.6%, but seeds that were dry stored for 44 weeks had lower germination rate -from 26.3-29.7%. Our results were similar to the germination of seeds after harvest (Yuan et al 2019), even though they were sown after a few months from the moment of harvesting. Radziul (2015), cultivating this species in the climatic conditions of Poland, stated that its frost resistance is su cient, which we also con rmed, because plant wintering both in pots and in the ground survived the winter (Table 1).…”

“…The results obtained for P. turczaninovii correspond to the percentage of P. patens seeds germinating after several months of storage (Priede and Kļaviņa 2011). Yuan et al (2019) conducted extensive research on the germination of P. turczaninovii and breaking of seed dormancy. Visually full seeds upon harvest germinated in 52.6%, but seeds that were dry stored for 44 weeks had lower germination rate -from 26.3-29.7%.…”

Germination of Pulsatilla cernua var. koreana Seeds as Influenced by Harvest Dates and Development of Seeds Analyzed by X-ray Imaging

“…Seeds stored in moist vermiculite did not germinate at all after 24 weeks of storage (Sang et al, 1996). Low germination rates may also result from the inclusion of nonviable seeds, incomplete development of vegetative organs [embryo and endosperm (empty seed)] (Esau, 1965), and damaged vegetative organs (Yuan et al, 2019).…”

“…Because of the presence of numerous trichomes developed on the seedcoat of Pulsatilla seeds (Yuan et al, 2019), Pulsatilla seeds immersed in water to separate full, viable seeds with developed vegetative organs (full seed) from empty, nonviable seeds, as demonstrated in Corylopsis coreana Uyeki seeds (Kim et al, 2017(Kim et al, , 2018, could not be evaluated. X-ray imaging may be useful to distinguish full seeds from empty seeds on a large scale, to evaluate images of seeds, to assess seed development, and to improve seed lot quality and germination (Carvalho et al, 2010;Kim et al, 2017Kim et al, , 2018Yuan et al, 2019).…”

“…Because of the presence of numerous trichomes developed on the seedcoat of Pulsatilla seeds (Yuan et al, 2019), Pulsatilla seeds immersed in water to separate full, viable seeds with developed vegetative organs (full seed) from empty, nonviable seeds, as demonstrated in Corylopsis coreana Uyeki seeds (Kim et al, 2017(Kim et al, , 2018, could not be evaluated. X-ray imaging may be useful to distinguish full seeds from empty seeds on a large scale, to evaluate images of seeds, to assess seed development, and to improve seed lot quality and germination (Carvalho et al, 2010;Kim et al, 2017Kim et al, , 2018Yuan et al, 2019). Low germination rates could result from harvesting immature seeds that cannot be verified by visual observation but can be detected by X-ray imaging (Kim et al, 2017(Kim et al, , 2018Yuan et al, 2019) and magnetic resonance imaging, which can be used to study the internal seed structure to determine the time of harvest of mature seeds as reported for Styrax japonicus (Roh et al, 2004).…”