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Floral nectary anatomy and ultrastructure in mycoheterotrophic plant, Epipogium aphyllum Sw. (Orchidaceae).

Święczkowska E, Kowalkowska AK - ScientificWorldJournal (2015)

Bottom Line: The floral analysis provides strong evidence to conclude that nectar is secreted on the upper surface of pink-coloured papillate ridges and epidermal (adaxial) cells at different place in spur, especially at the apex.The nectar secretion is not dependent on the colour form of E. aphyllum blooming shoots.The floral biology and ultrastructure differ from mycoheterotrophic plants known up to date.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Taxonomy and Nature Conservation, University of Gdansk, Wita Stwosza 59, 80-308 Gdańsk, Poland.

ABSTRACT
Epipogium aphyllum is a European-Asian obligatory mycoheterotrophic orchid containing no chlorophyll. Flowers are not resupinate with a sack-shape spur and cordate lip, which is divided into two parts: the basal (hypochile) and distal one (epichile). The floral analysis provides strong evidence to conclude that nectar is secreted on the upper surface of pink-coloured papillate ridges and epidermal (adaxial) cells at different place in spur, especially at the apex. The exudation on papillae has been observed through the entire anthesis and it has been stained on polysaccharides, proteins, and lipids. The dense cytoplasm of papillae contains profuse endoplasmic reticulum, plentiful vesicles (bigger ones with tannin-like materials), numerous mitochondria, sometimes dictyosomes, starch grains, and plastids with tubular structures. The large electron-dense bodies in cell walls are structurally the same as tannin-like materials from vesicles that are in contact with plasmalemma. The rupture of thin layer of swelled cuticle is caused by pressure of gathered substances exuded due to granulocrine secretion. The idioblasts with raphides occur mainly in tepals tissue. The dynamic changes of the nectar exudation, released through endocrine secretion, have been noticeable during the anthesis: both on the lip and inside the spur. The nectar secretion is not dependent on the colour form of E. aphyllum blooming shoots. The floral biology and ultrastructure differ from mycoheterotrophic plants known up to date.

No MeSH data available.


Related in: MedlinePlus

Epipogium aphyllum: (a) habitat in Darżlubska Forest, (b) normal blooming shoot, (c) inflorescence of normal blooming shoot, (d) half-albino blooming shoot (without yellow pigment), and (e) half-albino blooming shoot (without pink pigment). Visiting insects licking the fluids on the lip: (f, g) Meliscaeva cinctella and (h) Chrysanthia geniculata. (i) Lip epichile with four pink papillate ridges leading to the upwardly located spur and central furrow with pink smudge (sm); hypochile with two lateral lobes (LM). (j) Multicellular outgrowths on ridges consisted of groups of rounded papillae (LM) (ds: dorsal sepal, ls: lateral sepal, pt: petal, lip with hp–hypochile and ep–epichile, s: spur, and sm; pink smudge on epichile).
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fig1: Epipogium aphyllum: (a) habitat in Darżlubska Forest, (b) normal blooming shoot, (c) inflorescence of normal blooming shoot, (d) half-albino blooming shoot (without yellow pigment), and (e) half-albino blooming shoot (without pink pigment). Visiting insects licking the fluids on the lip: (f, g) Meliscaeva cinctella and (h) Chrysanthia geniculata. (i) Lip epichile with four pink papillate ridges leading to the upwardly located spur and central furrow with pink smudge (sm); hypochile with two lateral lobes (LM). (j) Multicellular outgrowths on ridges consisted of groups of rounded papillae (LM) (ds: dorsal sepal, ls: lateral sepal, pt: petal, lip with hp–hypochile and ep–epichile, s: spur, and sm; pink smudge on epichile).

Mentions: Flowers of a typical form (Figure 1(a)) were collected in July and August 2013. For comparison, there were also collected flowers of the half-albino type (without yellow colour) and another type of albino (without pink colour). Flowers were collected, respectively, on the 2nd, 3rd, 4th, 5th, 6th, and 8th days after the opening of a flower, in triplicate.


Floral nectary anatomy and ultrastructure in mycoheterotrophic plant, Epipogium aphyllum Sw. (Orchidaceae).

Święczkowska E, Kowalkowska AK - ScientificWorldJournal (2015)

Epipogium aphyllum: (a) habitat in Darżlubska Forest, (b) normal blooming shoot, (c) inflorescence of normal blooming shoot, (d) half-albino blooming shoot (without yellow pigment), and (e) half-albino blooming shoot (without pink pigment). Visiting insects licking the fluids on the lip: (f, g) Meliscaeva cinctella and (h) Chrysanthia geniculata. (i) Lip epichile with four pink papillate ridges leading to the upwardly located spur and central furrow with pink smudge (sm); hypochile with two lateral lobes (LM). (j) Multicellular outgrowths on ridges consisted of groups of rounded papillae (LM) (ds: dorsal sepal, ls: lateral sepal, pt: petal, lip with hp–hypochile and ep–epichile, s: spur, and sm; pink smudge on epichile).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4390210&req=5

fig1: Epipogium aphyllum: (a) habitat in Darżlubska Forest, (b) normal blooming shoot, (c) inflorescence of normal blooming shoot, (d) half-albino blooming shoot (without yellow pigment), and (e) half-albino blooming shoot (without pink pigment). Visiting insects licking the fluids on the lip: (f, g) Meliscaeva cinctella and (h) Chrysanthia geniculata. (i) Lip epichile with four pink papillate ridges leading to the upwardly located spur and central furrow with pink smudge (sm); hypochile with two lateral lobes (LM). (j) Multicellular outgrowths on ridges consisted of groups of rounded papillae (LM) (ds: dorsal sepal, ls: lateral sepal, pt: petal, lip with hp–hypochile and ep–epichile, s: spur, and sm; pink smudge on epichile).
Mentions: Flowers of a typical form (Figure 1(a)) were collected in July and August 2013. For comparison, there were also collected flowers of the half-albino type (without yellow colour) and another type of albino (without pink colour). Flowers were collected, respectively, on the 2nd, 3rd, 4th, 5th, 6th, and 8th days after the opening of a flower, in triplicate.

Bottom Line: The floral analysis provides strong evidence to conclude that nectar is secreted on the upper surface of pink-coloured papillate ridges and epidermal (adaxial) cells at different place in spur, especially at the apex.The nectar secretion is not dependent on the colour form of E. aphyllum blooming shoots.The floral biology and ultrastructure differ from mycoheterotrophic plants known up to date.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Taxonomy and Nature Conservation, University of Gdansk, Wita Stwosza 59, 80-308 Gdańsk, Poland.

ABSTRACT
Epipogium aphyllum is a European-Asian obligatory mycoheterotrophic orchid containing no chlorophyll. Flowers are not resupinate with a sack-shape spur and cordate lip, which is divided into two parts: the basal (hypochile) and distal one (epichile). The floral analysis provides strong evidence to conclude that nectar is secreted on the upper surface of pink-coloured papillate ridges and epidermal (adaxial) cells at different place in spur, especially at the apex. The exudation on papillae has been observed through the entire anthesis and it has been stained on polysaccharides, proteins, and lipids. The dense cytoplasm of papillae contains profuse endoplasmic reticulum, plentiful vesicles (bigger ones with tannin-like materials), numerous mitochondria, sometimes dictyosomes, starch grains, and plastids with tubular structures. The large electron-dense bodies in cell walls are structurally the same as tannin-like materials from vesicles that are in contact with plasmalemma. The rupture of thin layer of swelled cuticle is caused by pressure of gathered substances exuded due to granulocrine secretion. The idioblasts with raphides occur mainly in tepals tissue. The dynamic changes of the nectar exudation, released through endocrine secretion, have been noticeable during the anthesis: both on the lip and inside the spur. The nectar secretion is not dependent on the colour form of E. aphyllum blooming shoots. The floral biology and ultrastructure differ from mycoheterotrophic plants known up to date.

No MeSH data available.


Related in: MedlinePlus