Cytomorphological changes in the cerebral and ventral ganglionic neurosecretory cells during copulation in epigeic earthworms

In spite of hermaphroditism, most earthworm species reproduce by cross fertilization i.e. by the process of copulation of two mature partners. Mechanism of copulation in few earthworm species (Lumbricus terrestris) is known. However literature on neurosecretory control of copulation in earthworm is lacking. In the present study 30 pairs of conjugating earthworms of Eisenia fetida were collected from laboratory culture beds during 2016 of monsoon season. Cerebral and ventral ganglia of 10 pairs of conjugating earthworms and 20 pairs of post conjugation (2 hrs after separation, 4 hrs after separation) earthworms were fixed in Bouin’s fluid for cytomorphological studies on their cerebral neurosecretory cells. Earthworms (10 numbers) debrained through anterior transection of first five segments (brain present in 3rd segment) by sterilized paragon knife were studied to observe conjugation if any. Cerebral and ventral ganglia of 5 pairs of pre-conjugating earthworms were considered as control. Cerebral and ventral ganglia of earthworms displayed chiefly two types of neurosecretory cells such as A cells and B cells. The A cells are deeply stained AF-positive cells arranged in upper cortical tier beneath the perineurium and generally exhibiting process of axonal transport. The B cells, generally larger in size than A cells, are lightly or moderately stained with or without axonal transport and lie in between cortical A cells and central fibrous neuropile. In the cerebral ganglia the A cells outnumbered the B cells, while in the ventral ganglia the opposite is true. Debrained E. fetida survived but did not conjugate. Secretory dynamics in the cerebral and ventral ganglionic neurosecretory cells A and B were recorded in pre-conjugating, conjugating and post-conjugating earthworms. Absence of conjugation in debrained worms and exhibition of the same in earthworms with brain and its changes in neurosecretory profile clearly indicate involvement of cerebral neurosecretion in the phenomenon of conjugation in earthworm. Our result indicates probable involvement of cerebral neurohormone in the process of conjugation in E. fetida. DOI: http://dx.doi.org/10.5281/zenodo.394860

Molecular Verification of the UK National Collection of Cultivated Liriope and Ophiopogon Plants

open access articleA collection of cultivated Liriope and Ophiopogon plants was established in 1996–1998 and subsequently hosted at a horticultural college. Uncertainties about the identification of the accessions, compounded by potential errors in propagation and labelling have led to waning confidence in the identities of the plants in the collection. The potential for using DNA barcoding to determine the species identities of the accessions was investigated. The DNA barcode regions of the plastid ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit gene (rbcL) and nuclear ribosomal internal transcribed spacer (nrITS) were amplified. DNA sequence analysis allowed the sequences of the accessions to be compared to reference sequences in public databases. A simple haplotype map of the characteristic polymorphic positions in the rbcL regions was used to clearly distinguish between the two genera and assign Ophiopogon accessions to individual species or sub-groups of species. The ITS sequence data confirmed these genus and species assignations and provided greater resolution to distinguish between closely related species. The combination of two DNA barcodes allowed most of the accessions to be assigned to individual species. This molecular verification confirmed the identity of about 70% of the accessions, with the remaining 30% demonstrating a range of mistaken identities at the species and genus level

Genus-Specific Real-Time PCR and HRM Assays to Distinguish Liriope from Ophiopogon Samples

open access articleLiriope and Ophiopogon species have a long history of use as traditional medicines across East Asia. They have also become widely used around the world for ornamental and landscaping purposes. The morphological similarities between Liriope and Ophiopogon taxa have made the taxonomy of the two genera problematic and caused confusion about the identification of individual specimens. Molecular approaches could be a useful tool for the discrimination of these two genera in combination with traditional methods. Seventy-five Liriope and Ophiopogon samples from the UK National Plant Collections of Ophiopogon and Liriope were analyzed. The 5′ end of the DNA barcode region of the gene for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcLa) was used for the discrimination of the two genera. A single nucleotide polymorphism (SNP) between the two genera allowed the development of discriminatory tests for genus-level identification based on specific PCR and high-resolution melt curve (HRM) assays. The study highlights the advantage of incorporating DNA barcoding methods into plant identification protocols and provides simple assays that could be used for the quality assurance of commercially traded plants and herbal drugs

Notes on identity of some Indian species of Agapetes (Ericaceae)

Agapetes variegata (Roxb.) D. Don ex G. Don var. bhareliana Airy Shaw is treated here as a separate species; A. bhareliana (Airy Shaw) D. Banik & M. Sanjappa. Resurrected A. macrantha (Hook.) Hook. f., earlier treated as a variety under A. variegata (Roxb.) D. Don ex G. Don as A. variegata var. macrantha (Hook. f.) Airy Shaw. Two new combinations A. macrantha var. grandiflora (Hook.f.) Q.Banik & M.Sanjappa and A. macrantha var. oblanceolata (Airy Shaw) D. Banik & M. Sanjappa are proposed here. A. macrantha var. macrantha and A. macrantha var. oblanceolata are reported for the first time from India

A taxonomic study on the diversity of Indian Knema Lour. (Myristicaceae)

A taxonomic study on the diversity of the genus Knema Lour. belonging to the family Myristicaceae R. Br. in India revealed the distribution of the ten taxa under four series in North East and Peninsular India and Andaman and Nicobar Islands including two endemic species. Knema ser. Obovoideae W.J. de Wilde is synonymised here under ser. Knema. Series Knema is represented by two species and ser. Glaucae W.J. de Wilde by one species in North East India, while ser. Laurinae W.J. de Wilde is represented by three species and two subspecies in North East India and Andaman and Nicobar Island, and ser. Glomeratae W.J. de Wilde by 2 species in South and NE India. This is the first taxonomic study on the genus in India. All the taxa are cited with updated nomenclature, diagnostic characters, distribution, phonological data, vernacular names, line drawings, photo plates and specimens examined in various herbaria. Taxonomic keys are provided for easy identification of these taxa

Cytomorphological changes in the cerebral and ventral ganglionic neurosecretory cells during copulation in epigeic earthworms

In spite of hermaphroditism, most earthworm species reproduce by cross fertilization i.e. by the process of copulation of two mature partners. Mechanism of copulation in few earthworm species (Lumbricus terrestris) is known. However literature on neurosecretory control of copulation in earthworm is lacking. In the present study 30 pairs of conjugating earthworms of Eisenia fetida were collected from laboratory culture beds during 2016 of monsoon season. Cerebral and ventral ganglia of 10 pairs of conjugating earthworms and 20 pairs of post conjugation (2 hrs after separation, 4 hrs after separation) earthworms were fixed in Bouin’s fluid for cytomorphological studies on their cerebral neurosecretory cells. Earthworms (10 numbers) debrained through anterior transection of first five segments (brain present in 3rd segment) by sterilized paragon knife were studied to observe conjugation if any. Cerebral and ventral ganglia of 5 pairs of pre-conjugating earthworms were considered as control. Cerebral and ventral ganglia of earthworms displayed chiefly two types of neurosecretory cells such as A cells and B cells. The A cells are deeply stained AF-positive cells arranged in upper cortical tier beneath the perineurium and generally exhibiting process of axonal transport. The B cells, generally larger in size than A cells, are lightly or moderately stained with or without axonal transport and lie in between cortical A cells and central fibrous neuropile. In the cerebral ganglia the A cells outnumbered the B cells, while in the ventral ganglia the opposite is true. Debrained E. fetida survived but did not conjugate. Secretory dynamics in the cerebral and ventral ganglionic neurosecretory cells A and B were recorded in pre-conjugating, conjugating and post-conjugating earthworms. Absence of conjugation in debrained worms and exhibition of the same in earthworms with brain and its changes in neurosecretory profile clearly indicate involvement of cerebral neurosecretion in the phenomenon of conjugation in earthworm. Our result indicates probable involvement of cerebral neurohormone in the process of conjugation in E. fetida. DOI: http://dx.doi.org/10.5281/zenodo.394860