Flowering pattern, the structure of nectary surface and nectar secretion in two varieties of Ocimum basilicum L.

Mirosława Chwil

doi:10.5586/aa.2007.006

Abstract

The studies conducted in the years 2003-2004 covered two varieties of Ocimum basilicum L.: var. purpurascens Benth. and var. lactucaefolium I. The flower lifetime, daily flowering pattern, morphology of pollen grains and the abundance of nectar secretion of flowers were compared. The surface of the nectaries of O. basilicum var. lactucaefolium was observed using scanning electron microscopy (SEM). The automorphic nectaries of basil formed the following parts: a flat part from the side of the upper lip and a convex part with three protrusions on the opposite side. On the top of two outer protrusions, stomatal areas were located, responsible for nectar secretion. The stomata occurred at the level of other epidermal cells. On the average, nectar contained 42% of sugars. The sugar yield of flowers of var. lactucaefolium was 36% higher than this feature in var. purpurascens. In terms of their size, the pollen grains were rated as medium-sized. Their viability ranged 88-96%. The shape of the pollen grains was described as oblate and suboblate.

Highlights

The genus Ocimum numbers 150 plant species occurring in the natural environment in wild state, primarily in the tropical and subtropical zone of Africa and Asia (Szweykowscy, 2003)
Plants from the genus Ocimum provide food attractants to insects in the form of pollen and nectar. Flowers of this species were visited in large numbers by insects, in particular honey bees (R a j u, 1989; Malerbo - Souzai in. 2000)
The studies conducted in the years 2003-2004 covered two varieties of Ocimum basilicum L.: var. purpurascens Benth. and var. lactucaefolium I

Summary

Introduction

The genus Ocimum numbers 150 plant species occurring in the natural environment in wild state, primarily in the tropical and subtropical zone of Africa and Asia (Szweykowscy, 2003). Basil belongs to the family Labiatae which includes a numerous group of melliferous plants recommended for cultivation in order to improve bee pollen benefits (Jabłoński , 1997b, 2000; Ma sierowskaiKrzysiak , 2000; Bożek , 2003). Plants from the genus Ocimum provide food attractants to insects in the form of pollen and nectar. Flowers of this species were visited in large numbers by insects, in particular honey bees Studying the influence of different honey samples on resistant Staphylococcus-aureus strains, Garcia et al (2001) showed that honeys from labiate plants inhibited most strongly the growth of staphylococcus

Methods

Results

Discussion

Conclusion