Taxonomic Consequences of Seed Morphology and Anatomy in Three Lupinus Species (Fabaceae-Genisteae)

Document Type : Original Article

Author

Botany and Microbiology Department, Faculty of Science, Alexandria University, Alexandria, Egypt

Abstract

The objective of this paper is to study seed coat morphological and anatomical features of three Lupinus
species; L. albus L., L. digitatus Forssk. and L. angustifolius L., in order to reveal the taxonomic
relationships among them. Among seed coat macromorphological characters used were seed dimensions,
seed weight and testa color, while those of the hilum were lens and macula raphalis. Seed coat
micromorphological features revealed a similarity between L. digitatus and L. angustifolius since the
outer periclinal walls of the isodiametric epidermal cells are tuberculate. The summit of each tubercle
takes the form of umbrella with a central elevation in the former species, while each tubercle possesses
long and narrow tips in the latter one. However, in L. albus the outer periclinal walls of the isodiametric
epidermal cells are combination between pusticulate and reticulate. The anatomy of seed coat of Lupinus
species shows that it is formed of two layers, the exotesta and the mesotesta. The exotesta is
distinguished into two sublayers; the outer epidermis which is formed of malpighian cellulosic thickwalled
cells (macrosclereids) and the inner hypodermis of hourglass thick-walled cells with large
intercellular spaces (osteosclereids). On the other hand the mesotesta layer is formed of parenchyma
cells. L. angustifolius, L. digitatus and L. albus displayed the same intermediate cotyledon type with
some specification for L. albus.

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