In Vivo Chromosome Doubling of Prunus lusitanica and Preliminary Morphological Observations

Abstract

<jats:p><jats:italic>Prunus lusitanica</jats:italic> (2<jats:italic>n</jats:italic> = 8<jats:italic>x</jats:italic>) and <jats:italic>Prunus laurocerasus</jats:italic> (2<jats:italic>n</jats:italic> = 22<jats:italic>x</jats:italic>) are evergreen woody shrubs commonly used in landscapes across the United States and Europe. To reduce the difference in ploidy between these species and with the expectation of successful hybridization, an experiment was performed to double the chromosome number of <jats:italic>P. lusitanica</jats:italic>. Colchicine was applied at 0%, 0.2%, 0.4%, and 0.8% (w/v), and 125 µM oryzalin as a viscous liquid to the apical meristem of open-pollinated <jats:italic>P. lusitanica</jats:italic> seedlings. Solutions were semisolidified using 0.55% agar (w/v). Cellular penetration was increased by adding 1% dimethyl sulfoxide (v/v) in all groups except oryzalin. As a result, three chromosome doubled (2<jats:italic>n</jats:italic> = 16<jats:italic>x</jats:italic>) plants, one 2<jats:italic>n</jats:italic> = 12<jats:italic>x</jats:italic> plant, and 14 cytochimeras (2<jats:italic>n</jats:italic> = 8<jats:italic>x</jats:italic> + 16<jats:italic>x</jats:italic>) were recovered. Application of 125 µM oryzalin had a meristem-survival rate of 17%, statistically lower than all other treatments. The oryzalin treatment also produced the highest number of altered ploidy seedlings. Oryzalin at 125 µM was the most effective chromosome doubling agent in this experiment. Phenotypic examination indicated that chromosome doubled (2<jats:italic>n</jats:italic> = 16<jats:italic>x</jats:italic>) plants displayed shorter stems, thicker leaves, and fewer but larger guard cells than the untreated controls.</jats:p>

In Vivo and In Vitro Chromosome Doubling of ‘I3’ Hemp

“…Survival ranged from 11% for the 0.1%, 6-h colchicine treatment to 89% for the 0.2%, 3-h colchicine treatments. Schulze and Contreras (2017) experimented with in vivo chromosome doubling on Portuguese Cherrylaurel and observed a range of survival among treatments. Similar to our study, colchicine applied at 0.2% resulted in the highest survival among treatments using seedlings instead of stem cuttings.…”

“…Ploidy analysis was conducted according to Schulze and Contreras (2017) with the modification that a Quantum P flow cytometer (Quantum Analysis GmbH, M€ unster, Germany) was used. All surviving cuttings and explants were evaluated using Pisum sativum 'Citrad' (2C 5 8.76 pg) as the internal standard for genome size estimation.…”

Morphological and Molecular Identification of Dactylonectria macrodidyma as Causal Agent of a Severe Prunus lusitanica Dieback in Italy

“…[9]. In contrast, P. lusitanica is quite resistant to shot-hole disease (caused collectively by different bacterial and fungal pathogens) [10].…”