Diversification and reticulation in the circumboreal fern genus Cryptogramma.

RESUMEDes nombres chromosomiques nouveaux sont rapportes pour les genres Trichomanes, Selenodesmium, Vandenboschia, Crepidomanes et Gonocormus. Dans le genre Microgonium, nous avions mis en evidence des complexes apomictiques aneuploides avec des nombres chromosomiques eleves. Dans les genres Vandenboschia et Gonocormus, certaines populations forment des complexes sexuels polyploides.

Observations Cytotaxonomiques sur des Hyménophyllacées Africaines: II. D'Autres Genres

SUMMARY1. The karyological phenomena in the life-cycle of Fomes lividus Kalchbr., a resupinate member of the family Polyporaceae has been studied in detail.2. The young basidium is distinctly binucleate. This dikaryotic condition comes to an end with their fusion to form a synkaryon. The synkaryon first undergoes an interphasic enlargement followed by the appearance of chromatic materials as reticulate structure. Subsequently, from the reticulum typical chromosomes (2 n = 6) are formed. A haploid chromosome set constituting a genome (n = 3) forms a daughter nucleus at each pole. The orientation of the spindle of the first division of meiosis (heterotypic) is more or less transverse while in the second division (homotypic) it shows irregularities. A third nuclear division occurs forming the eight nucleate condition of the basidium. Four of these eight nuclei migrate into four developing basidiospores while the other four degenerate in the collapsing basidium. The nucleus within the basidiospore often divid...

https://www.tandfonline.com/doi/pdf/10.1080/00087114.1966.10796207

Contribution to the Cytology of Hymenomycetes. VII. Karyological Studies in Fomes Lividus Kalchbr

SUMMARY1. The karyological cycle in the life-history of Flammula dilepis, brown-spored member of the family Agaricaceae, has been studied in detail.2. Young binucleate basidia are the dilated hyphal tips, each having a simple clamp-connexion at the base. This dicaryotic condition comes to an end with the fusion of these two nuclei of a basidium forming a synkaryon. This synkaryon then enlarges and ultimately undergoes reduction division (heterotypic). With the onset of prophase, chromosomes make their appearance and during metaphase 6 clear bivalents are evident (2 n = 12). Bivalents then separate and the two sets form two daughter nuclei, each with 6 chromosomes. The second division is homotypic and the four daughter nuclei thus formed also contain six chromosomes (n = 6) each. The orientation of the spindle in the first division of meiosis is always transverse, while it is irregular during the second division. The four daughter nuclei then migrate into the four developing basidiospores through the steri...

Contribution to the Cytology of Hymenomycetes. VI. Karyological Studies in Flammula Dilepis B. & Br.

The present work has been undertaken to study the development of the basidiocarp of Flammula dilepis B. & BE. from the "anlagen". The "anlagen" which are nothing but aggregates of hyphal masses, become gradually differentiated into stipe and pileus by continued upward growth. During formation of the pileus, apical hyphae of the stipe grow upward, then radially outwards and finally downwards. Gradually, hymenial primordium becomes evident towards the lower side of the pfleus as a dense palisade layer of vertical hyphae. This layer, by further growth and differentiation, gives rise to the gills within a gill-chamber. Centrifugal growth of the pileus causes rupture of the gill-chamber thus exposing the gills which are situated on the underside of the pileus.

Balen Nandi

Papers

Contribution to the Cytology of Hymenomycetes. VII. Karyological Studies in Fomes Lividus Kalchbr

Contribution to the Cytology of Hymenomycetes. VI. Karyological Studies in Flammula Dilepis B. & Br.

Studies on morphogenesis inFlammula dilepis B. &Br.