This paper presents new records and noteworthy data on the following taxa in
SE Europe and adjacent regions: red algae Sheathia confusa, parasitic fungus
Anthracoidea caryophylleae, mycorrhizal fugus ...Hydnellum caeruleum,
bryoparasitic fungus Octospora erzbergeri, liverwort Cephaloziella
baumgartneri, mosses Hamatocaulis vernicosus, Streblotrichum convolutum var.
commutatum and Ulota crispula, monocots Ophrys bertolonii subsp. bertolonii,
Ophrys scolopax subsp. cornuta and Spiranthes spiralis and dicots Androsace
hedraeantha, Hieracium mrazii, Ramonda nathaliae and Triglochin palustris
are given within SE Europe and adjacent regions.
Within the agamic
Pilosella
complex, apomixis (asexual reproduction through seed) involves apospory, parthenogenesis, and autonomous endosperm development. Observations of reproductive biology in
P. ...brzovecensis
throughout four growing seasons in the garden have shown that both tetraploid and pentaploid plants of this species do not produce viable seeds and reproduce exclusively vegetatively by underground stolons. The reasons for the seed development failure were unknown, therefore our research focused on the analysis of reproductive events in the ovules of this taxon. We found that apospory was initiated in the ovules of both cytotypes. Multiple aposporous initial (AI) cells differentiated in close proximity to the megaspore mother cell (MMC) and suppressed megasporogenesis at the stage of early prophase I. However, none of the AI cells was able to further develop into a multi-nucleate aposporous embryo sac (AES) due to the inhibition of mitotic divisions. It was unusual that callose was accumulated in the walls of AI cells and its synthesis was most likely associated with a response to the dysfunction of these cells. Callose is regarded as the isolating factor and its surprising deposition in the ovules of
P. brzovecensis
may signal disruption of reproductive processes that cause premature termination of the aposporous development pathway and ultimately lead to ovule sterility. The results of our embryological analysis may be the basis for undertaking advanced molecular studies aimed at fully understanding of the causes of female sterility in
P. brzovecensis
.
This paper presents new records and noteworthy data on the following taxa in
SE Europe and adjacent regions: brown alga Heribaudiella fluviatilis, red
alga Batrachospermum skujae, saprotrophic fungus ...Gnomonia
geranii-macrorrhizi, mycorrhizal fungi Amanita alseides and Russula
griseascens, liverwort Ricciocarpos natans, moss Blindia acuta, Leucodon
sciuroides var. morensis and Pseudostereodon procerrimus, monocots Allium
ampeloprasum, Carex ferruginea and Carex limosa and dicots Convolvulus
althaeoides, Fumana aciphylla, Hieracium petrovae, Lamium bifidum subsp.
bifidum and Ranunculus fontanus are given within SE Europe and adjacent
regions.
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