An illustrated step-by-step protocol for investigating liverwort chromosomes

Cytogenetic studies in bryophytes have been limited by the difficulty of obtaining sufficient dividing nuclei and by the absence of modern protocols. The technical difficulties stem from the plants’ small size and lack of roots and pollen mother cells, the main sources of cells in division in vascular plants. In bryophytes instead, tiny sporophytes, antheridia, or phyllid meristems must be used to obtain meiotic or mitotic chromosome spreads. We here describe the preparation of such spreads from phyllids, antheridia, and sporophytes in several species of liverworts and compare available protocols with or without prefixation treatments. We also provide illustrated step-by-step instructions. The three prefixation agents (including colchicine) that we tested failed to improve synchronization of cell divisions. Young sporophytes were the best source of diploid synchronized cells, while antheridia were the best source of haploid cells. For meiotic nuclei, a short fixation of capsule tissue at the right developmental stage with 45% acetic acid sufficed to conserve the DNA for cytological investigations, while for mitotic nuclei, fixation in 3:1 ethanol/glacial acetic acid for a longer period (4–24 h) worked well.

Features of the ontogenesis of gametophytes of strains (Matteuccia struthiopteris (L.) Tod.) under conditions of different density of sowing of disputes

The article deals with the effect of sowing density of spores on ontogenesis of gametophytes Matteuccia struthi-opteris (L.) Tod. This species is included in the Red Data Book of the Kursk Region (Krasnaia…, 2017). The ability to form viable gametophytes from spores in Matteuccia struthiopteris is often reduced and depends on many factors, including the population density of the seedlings themselves. Among the numerous forms of thalli of gametophytes in M. struthiopteris (filamentous, spatulate, asymmetric, cordate, wide-heart), only wide-heart thalli form an archegonial cushion capable of fertilization and formation of a zygote with further development of sporophyte. Under natural conditions, the presence of young sporophytes is an important factor contributing to the rejuvenation of populations of M. struthiopteris and an increase in their vitality. In the course of the study, it was established how significant the mutual influence of gametophytes is for their development.

PERBANYAKAN TANAMAN HIAS AIR Microsorum pteropus MELALUI KULTUR KANTONG SPORA PADA BERBAGAI SUBSTRAT

Produksi massal tanaman hias air pakis jawa Microsorum pteropus melalui pemotongan rhizoma terlihat kurang efisien sedangkan melalui kultur in vitro spora masih sulit dilakukan masyarakat. Salah satu pendekatan baru dalam perbanyakan tanaman M. Pteropus melalui kultur kantong spora telah berhasil dilakukan. Tujuan penelitian adalah untuk menentukan media dalam perbanyakan tanaman M. pteropus melalui kultur kantong spora. Potongan daun yang mengandung satu kantong spora diletakkan di atas media tanam, ditutup dengan plastik transparan, dan ditaruh pada lingkungan di luar ruangan (outdoor). Media tanam yang digunakan yaitu: A) cacahan akar pakis; B) serutan kayu; C) cacahan akar pakis + serutan kayu; D) cacahan akar pakis + serutan kayu + kompos; E) pasir gunung berapi (pasir malang); F) abu sekam padi; G) pasir; dan H) tanah. Hasil penelitian menunjukkan bahwa perkembangan sporofit muda (young sporophye) sudah mulai terlihat pada bulan pertama sampai ketiga setelah tanam. Sporofit muda yang berkembang dari kantong spora yang dipelihara pada media pasir, media tanah dan media campuran serutan kayu + akar pakis + kompos menunjukkan rata-rata persentase tanaman hidup yang paling tinggi yaitu 48%. Sebaliknya sporofit muda paling sedikit berkembang pada media akar pakis, media abu sekam padi dan media campuran akar pakis, dan serutan kayu. Berdasarkan hasil tersebut maka media terbaik untuk perbanyakan M. pteropus di luar ruangan melalui kultur kantong spora adalah media tanah dan media campuran akar pakis + serutan kayu + kompos.Mass production of Microsorum pteropus through rhizome cuttings has been deemed not efficient while the application of in vitro culture of its spores is still technically difficult to be performed by farmers. A novel approach to mass-produce M. pteropus trough sori culture has been developed and is relatively easy to perform. This study was aimed to determine a suitable propagation media for sori culture of M. pteropus. Small cut fronds containing one sorus were laid on the culture media and covered with a transparent plastic sheet and left on outdoor conditions. The culture media used were: A) fern-root; B) wood shavings; C) fern-root + wood shavings; D) fern-root + wood shavings + compost; E) volcanic sand; F) rice husk ash; G) sand; and H) soil. The results showed that young sporophytes developed in the 1st to 3rd month after culture. The young sporophytes developed in the sand, soil and mixture of wood shavings + fern-root + compost medium showed higher numbers of live plants (48%). In contrast, the lower numbers of live young sporophyte were found in the fern-root, rice husk ash, and mixture of fern-root + wood shavings medium. Based on these results, the best alternative media for propagation of M. pteropus through sori culture on the outdoor conditions are soil media and the mixture of fern roots + wood shavings + compost media.

Fungal associations in gametophytes and young sporophytic roots of the fern Nephrolepis exaltata

Fungal associations in gametophytes and young sporophytic roots of the fernNephrolepis exaltataInformation is limited on the presence of endophytic fungal associations in green gametophytes and young sporophytes of extant ferns. Nothing is known about their presence in Polypodiales, the largest order among extant ferns. We screened chlorophyllous gametophytes and young sporophytes ofNephrolepis exaltata(L.) Schott., (Lomariopsidaceae, Polypodiales) growing naturally on soil, brick and coir for the presence of fungal endophytes. Gametophytes and young sporophytes growing on different substrates were invariably colonized by septate endophytic fungi. Hyaline or brown, regularly septate, inter- or intracellular hyphae with moniliform cells or microsclerotia characterized septate endophytic fungi. However, only the roots of young sporophytes growing on soil and bricks harboured arbuscular mycorrhizal (AM) fungi. The AM morphology conformed to the intermediate type with intracellular hyphal coils, arbusculate coils and intercellular hyphae. No AM fungal spores could be retrieved from the soil on which gametophytes and young sporophytes were growing. The observations in this study support the idea that the septate fungal endophytes could confer an ecological advantage on colonized individuals, especially on nutrient deficient substrates.