Meiosis, pollen morphology and perianth stomata of some taxa of Amaranthus L. (Amaranthaceae) in Nigeria

Abstract

The species are made up of three ploidy levels of chromosome complements with haploid number of n = 16 for the two varieties of Amaranthus hybridus, n = 17 for the two varieties of A. spinosus and A. viridis and n = 32 for A. dubius. All the species are characterised by aberrant meiosis except A. dubius. High degree of meiotic abnormalities such as multivalents and stickiness of chromosomes leads to clumping, overlapping of chromosomes and unequal segregation of chromosomes at anaphyse I. The measurements of the pollen grains showed some overlaps with the size distribution ranging from 23.52–35.28 μm. The species are highly fertile with over 85% pollen stainability except A. dubius and A. hybridus, green variety that had between 65.8% and 72% respectively. The stomata are of pericytic and anomocytic types and they showed a high degree of overlaps in their xL/xB. The high degree of overlaps in most of the micromorphological features confirms the closeness of the species and the difficulty in separating the species.

Characterization of Grain Amaranth (Amaranthus spp.) Germplasm in South West Nigeria Using Morphological, Nutritional, and Random Amplified Polymorphic DNA (RAPD) Analysis

“…These accessions can be considered as sources of genes for seed yield, plant vigor, and mineral elements in amaranth improvement programs. Ugborogho and Oyelana [42] observed in their investigations that many accessions of A. hybridus exist and they tend to vary in plant height, leaf, stem and seed inflorescence color, and grain yield. In this study, A. hybridus (A28 and A29) in Clusters II and III can be good sources of genes for starch, protein, and selenium content since they are high in these traits.…”

Macro‐ and micromorphological evidence for infraspecific separation of taxa in Hibiscus rosa‐sinensis L. (Malvaceae)

“…Differences in stomatal dimensions as a tool in taxa separation (PEREIRA-SHETEOLU 1992 The occurrence of different stomatal complexes in the same species is not uncommon among angiosperm groups. It has been reported in varieties of Ipomuea barcirus ( UGBOROGHO et al 1992) and cultivars of Dioscorea spp. .…”

“…This is keeping with the yearning need for better ways for germplasm description, 202 Feddes Repert., Berlin 110 (1999) 3-4 identification and conservation. It is widely acknowledged that variations at the varietal level have provided important dignostic tools among angiosperm species (GRAHAM 1963;MCDOUGAL 1973;GILL 1977;UGBOROGHO & SODIP0 1985;UGBOROGHO & ADETULA 1988;UGBOROGHO et al 1992. Traditionally, H. rosa-sinensis varieties have been separated on the basis of floral colour which ranges from red, pink, orange, yellow and white and the red colour is reported to be the most primitive (HU 1955).…”