Chromosome numbers and polyploidy in Polish angiosperms

Our survey of data collected in the Chromosome Number Database for Polish angiosperms indicated that the 1,498 species with chromosome counts represent 40% of the total angiosperms (3,719) occurring in Poland, including 1,205 native species (53% of native species) and 194 anthropophytes (56% of anthropophytes). The chromosome numbers are known for all native species occurring in Poland within 298 genera and 46 families, and for all anthropophytes from 79 genera and 11 families. The remaining angiosperm groups are less explored: chromosome counts from Poland are known for 9% of cultivated species and 5% of ephemerophytes. According to generic basic chromosome numbers, 46.44% of Polish angiosperms have been classified as polyploid. By three different threshold methods, the contribution of polyploid plants to the Polish flora is 64.64%, 50.89% or 42.89%. Polyploidy is more common among indigenous than non-indigenous plants, and the ploidy distribution among plants from the Polish Tatras does not differ significantly from that observed in the rest of native Polish plants

Male adventitious roots of Rumex thyrsiflorus Fingerh. as a source of genetically stable micropropagated plantlets

Rumex thyrsiflorus Fingerh. is one of the few dioecious plant species that have sex chromosomes. The chromosome constitution of females is 2n = 12A + XX and 2n = 12A + XY1Y2 of males. It is a medicinally important plant species and has also been the object of studies on the structure and function of sex chromosomes and sex ratio. An efficient plant regeneration protocol was developed from karyologically stable male roots that had been derived from a long-term liquid culture. The root segments were grown on MS medium supplemented with the following plant growth regulators: 2.4-D, NAA, kinetin, BAP and TDZ. The highest frequency (81.73 %) of adventitious shoot formation (16.27 shoots/explant) was obtained on MS + 0.5 mg/l TDZ. Regenerated shoots were successfully rooted on ½ MS + 2 % sucrose + 0.5 mg/l IBA and acclimated to in vivo conditions. Histological analysis revealed indirect (via callus) adventitious shoot formation. The cells of the morphogenetic callus were surrounded by a fibrillar structure that was similar to the extracellular matrix. Molecular analysis based on genetic sex markers confirmed that all of the root explants were male. The genetic stability of the regenerated plantlets was confirmed using random amplified polymorphic DNA analysis. This is the first report concerning the micropropagation protocol for R. thyrsiflorus Fingerh. from male roots derived from a long-term liquid culture, which offers a unique opportunity to obtain true-to-type plants of the same sex

Polyploidy, alien species and invasiveness in Polish angiosperms

Chromosome numbers, mainly for Polish flora, were examined in order to investigate whether such features as chromosome numbers and polyploid frequencies are correlated with a plant’s origin (native vs. alien) and invasiveness. Polyploid frequencies were estimated using three methods: the 11 and 14 thresholds and the 3.5 x value. Comparisons of the 2n values were done on different levels: in all angiosperms and in dicots and monocots separately. Invasive and non-invasive plants were compared in the entire dataset and in alien species only. Significant differences in both chromosome numbers and polyploid frequencies between alien and native species were observed. In most cases, native plants had more chromosomes and were more abundant in polyploids than in alien species. Also, monocots had higher polyploid frequencies than dicots. Comparisons of invasive and non-invasive plants done for all of the data and only for alien species showed that invasive species generally had more chromosomes and polyploids were more frequent in them than in the latter group; however, these differences were not always statistically significant. Possible explanations for these observations are discussed

Chromosome numbers and polyploidy in life forms of Asteraceae, Poaceae and Rosaceae in Polish flora

The chromosome numbers and frequency of polyploids were compared in life forms of Asteraceae, Poaceae and Rosaceae. Both parameters were higher in Poaceae and Rosaceae than in Asteraceae. Among the life forms, longlived plants including perennials and woody plants (shrubs and trees) generally had higher chromosome numbers and consequently polyploid frequencies than short-lived species (annuals and biennials). The families surveyed have different frequencies of life forms. Asteraceae and Rosaceae are both dicots, but the life forms in Asteraceae are more similar to Poaceae than to Rosaceae. To separate the influence of life form, in a series of tests we compared life forms from the same families. These results also showed that long-lived forms generally have more chromosomes than short-lived ones

The first evidence of a host-to-parasite mitochondrial gene transfer in Orobanchaceae

Several parasitic plants are known to have acquired mitochondrial genes via a horizontal transfer from their hosts. However, mitochondrial gene transfer in this direction has not yet been found in the parasite-rich family Orobanchaceae. Based on a phylogenetic analysis of the mitochondrial atp6 gene in selected species of Orobanche s.l., we provide evidence of a host-to-parasite transfer of this gene in O. coerulescens, which is a Eurasiatic species that parasitises Artemisia (Asteraceae). We did not find the original Orobanche atp6 gene in this species, which suggests that it has been replaced by a gene that was acquired from Asteraceae. In addition, our data suggest the occurrence of a second HGT event in the atp6 sequence - from Asteraceae to Phelipanche. Our results support the view that the transfer of genetic material from hosts to parasites influences the mitochondrial genome evolution in the latter

Extracellular matrix surface network is associated with non-morphogenic calli of Helianthus tuberosus cv. Albik produced from various explants

Helianthus tuberosus is economically important species. To improve characters of this energetic plant via genetic modification, production of callus tissue and plant regeneration are the first steps. A new, potentially energetic cultivar Albik was used in this study to test callus induction and regeneration. Callus was produced on leaves, petioles, apical meristems and stems from field-harvested plants but was totally non-morphogenic. Its induction started in the cortex and vascular bundles as confirmed by histological analysis. The surface of heterogeneous callus was partially covered with a membranous extracellular matrix surface network visible in scanning and transmission electron microscopies. The results clearly indicate that: (i) the morphogenic capacity of callus in topinambur is genotype dependent, (ii) cv. Albik of H. tuberosus proved recalcitrant in in vitro regeneration, and (iii) extracellular matrix surface network is not a morphogenic marker in this cultivar