Development of the root system inSpirodela polyrhiza (L.) schleiden (Lemnaceae)

Cellular Features of the Fronds and Turions in Spirodela polyrhiza

“…Spirodela polyrhiza, a giant duckweed, of the family Lemnaceae is a small, free-floating aquatic species and well-known for a peculiar mode of vegetative reproduction. Fronds are the leaflike structures derived from fused stems and leaves (Landolt, 1986(Landolt, , 1998Lemon & Posluszny, 2000), with a multiple root system on each frond (Kim, 2007). A mother frond produces daughter fronds from two meristematic regions several times during growth, but turions are also formed within mother frond toward the end of growing season as dormant overwintering structures.…”

“…The turions, dormant structures adapted for survival during the winter by sinking to the bottom of the water, were also included for comparison. Structural aspect of the root system was excluded in the study, since it was discussed in detail as a separate paper (Kim, 2007).…”

Structural Differentiation of the Connective Stalk inSpirodela polyrhiza(L.) Schleiden

“…The offspring is always connected to the mother frond via a translucent stalk. Thus, the CT probably functions mechanically to maintain connection between the fronds as well as a channel to transport nutrients from the mother frond to the offspring (Kim, 2007(Kim, , 2013White & Wise, 1998). Cells fi lled with tanniferous materials were found in the CT as in fronds of Spirodela (Kim, 2013), and they are known to strongly absorb ultraviolet rays (Bonnet et al, 1996).…”

“…The giant duckweed, S. polyrhiza, is a small, free-fl oating aquatic plant with rapid growth exhibiting the piling up of fronds in a short period of time as in Lemna minor. It consists only of connected fronds, leaf-like structures developed from fused stems and leaves (Kim, 2011(Kim, , 2013Kim & Kim, 2000;Kwak & Kim, 2008;Landolt, 1998;Lemon & Posluszny, 2000), with several roots on the lower surface of each frond (Kim, 2007). Much attention has been given to the structural aspects of duckweeds, since a great reduction in plant organization has been well demonstrated within the small body.…”

Padrões de alocação de carbono estrutural e não estrutural em cinco espécies de lentilhas d´água (Lemnaceae)

“…Como já mencionado, essas plantas são caracterizadas pelo tamanho reduzido e por sua estrutura composta de frondes arredondadas com uma ou duas juntas à base, sem diferenciação entre caule e folha e 0-21 raízes sem pelos radiculares BORISJUK;LAM, 2013;FAO, 1999;. O sistema vascular dessas plantas é reduzido e nas raízes são constituídos de um elemento traqueíde, dois elementos de vaso e seis células de parênquima floemáticas (KIM, 2007).…”