References
McNeal, J R, Arumugunathan, K, Kuehl, J V,
Boore, J L, and dePamphilis, C W. 2007. Systematics and plastid
genome evolution of the cryptically photosynthetic parasitic plant
genus Cuscuta (Convolvulaceae). BMC Biology, 5(55).
In this article, McNeal describes and tests the
phylogeny and steps of plastid genome change in the genus Cuscuta.
Cuscuta pentagona is not directly studied in these
experiments, but the genus is described in depth.
According to McNeal, Cuscuta is a paraphyletic group.
There are subgenera determined by morphological differences
in style and stigma. It is difficult to
distinguish between species of Cuscuta because of the few
morphological characteristics—as it is lacking roots and typically
noticeable leaves. This difficulty is described
as an introduction to the genome mapping experiment.
Other species of Cuscuta are discussed in more depth
due to their usefulness in the experiment. This
source clearly outlines the genetics of the genus Cuscuta and
its loss of certain genes throughout speciation.
This source is particularly useful for its descriptions of
Cuscuta and the explanation of the genus’s morphology and life
cycle.
Revill, M W, Stanley, S, and Hibberd, J M.
2005. Plastid genome structure and loss of photosynthetic ability in
the parasitic genus Cuscuta. Journal of Experimental Botany,
56(419), 2477-2486.
This study focuses on the plastid genome of 15
species of Cuscuta, one of which is Cuscuta pentagona.
Revill believes, due to much evidence in similar
species and in Cuscuta itself, that Cuscuta may be
losing its photosynthetic abilities and have a shrinking plastid
genome. Each of the 15 species of Cuscuta
is studied within the experiment to see if certain clades are losing
the specific photosynthesis genes faster than others.
The impending loss of photosynthesis is due to the parasitic
nature of Cuscuta. For most of its energy,
Cuscuta relies on its host plant.
Cuscuta wraps around its host and leaches nutrients from the
host’s phloem. The stem of Cuscuta is
still thought to be somewhat photosynthetic. I
felt this article to be very informative on the nature of parasitic
plants. The introduction explains the premise for
the experiment with clarity and detail. The
experiment seems sound and well documented.
Runyon, J B, Mescher M C, and De Moraes, C M.
2006. Volatile chemical cues guide host location and host selection
by parasitic plants. Science, 313(5795), 1964-1967.
Runyon, et al. explains methods by which
parasitic plants find a host. Cuscuta
pentagona was used to test and best demonstrate methods by which
a host plant was located and selected. In
Runyon’s experiment, dodder was attracted to a tomato plant at only
a few centimeters germinated. It was determined
that the attraction was to the plant’s volatile chemical excretions.
There was also a difference between hosts, as one compound of
wheat repelled dodder. The adaptation of dodder
to detect a favorable host plant at an early time reflects on its
lack of root system and limited photosynthesis.
This source is thorough in explaining methods by which dodder
locates a host plant and why Cuscuta as a
parasitic plant would need to locate a certain host early in growth.
Sherman, T D, Bowling, A J, Barger, T, and
Vaughn, K C. 2008. The vestigial root of dodder (Cuscuta
pentagona) seedlings. International Journal of Plant
Sciences, 169(8), 998-1012.
This article discusses the root of dodder,
Cuscuta pentagona, focusing on the seedling stage of life.
The roots of Cuscuta are different from many other
genera of dicots. The root is lacking many structures,
which are discussed in detail. The “root” may not even be considered
a root, but rather something slightly less. The
modified root may have evolved to allow the shoot more means for
growth in a shorter time, making Cuscuta a more threatening
parasite. The lack of typical structures also
causes Cuscuta to be reliant on its parasitism.
Sherman’s research on the germination and physiology of
Cuscuta pentagona is documented in this article.
Sherman’s work is well documented and the meanings of his
findings are spelled out clearly. The information
on root and shoot germination and physiology gives insight on
Cuscuta’s parasite-host relationship as it pertains to the
structure of the plant itself.
Wright, M, Welsh, M, and Costea, M. 2011.
Diversity and evolution of the gynoecium in Cuscuta (dodders,
Convolvulaceae) in relation to their reproductive biology: two
styles are better than one. Plant Systematics & Evolution, 296(1/2),
51-76.
In this article, Wright looks at the gynoecium
of Cuscuta to determine the phylogeny.
Because species of Cuscuta are very similar, stigma and style
morphology has been used to classify and differentiate.
The gynoecium is part of these structures.
Many species of Cuscuta were studied. The
morphology was used in this experiment.
Microscopic views of the gynoecium tissue were viewed.
Characteristics were chosen to split the genus further.
Wright found that genera with two types of gynoecium or
unequal gynoecium fared better. This is a
morphological adaptation that allows more opportunity for new
species to evolve. Wright found that the best way
to distinguish between Cuscuta species is indeed to use the
gynoecium characteristics. He found that certain
characteristics work to classify Cuscuta at different levels.
This source give information about how Cuscuta species
are identified and explains some adaptations and reproductive
strategies.
Web References
Cook explains many aspects of dodder as she
leads up to her experiment which focuses on the control of dodder.
She discusses many useful topics that introduce the reader to
Cuscuta pentagona such as taxonomy, habitat range, and hosts.
Cook goes on to describe the problems Cuscuta causes such as
economic loss due to crop damage and fast spreading.
She talks about each chemical and its effect on dodder, then
on biological controls, then explains her research objective.
Her research focuses on the control agent Aternaria
destruens and its use in the control of dodder.
This article is a great source for many aspects of
Cuscuta, and it is explained both generally and in depth.
Cook’s research seems sound and well-studied.
This webpage by and in tribute of Robert
Freckmann, a long time professor of biology at the University of
Wisconsin- Stevens Point, gives information about many plants.
A taxonomy is given to the family level.
Characteristics of each level are described.
There are hand drawn pictures to go along with the characteristics.
It is clear that much work and thought went into each
description. Cuscuta is placed in its own family
Cuscutaceae, rather than with Convolvulaceae.
However, that may have been accepted at the time, and it is pointed
out that Cuscutaceae is often synonymous with Convolvulaceae.
There is a segment on Cuscuta pentagona specifically focusing
on its role in Wisconsin. This resource will be
helpful for defining characteristics of Cuscuta pentagona and for
basic information.
Ombrello, T. Dodder. Biology
Department, Union County College, Cranford, NJ.
The entries found on this website feature a
plant from the Union County College greenhouse every so often.
Information about that plant is posted.
Cuscuta is featured on this site. Many
common names of Cuscuta are given as well as background
information. The common names will be useful to
relate the plant to more people as they may know it.
The time scheme of dodder from seed to adult to reproduction
is spelled out clearly as it is seen in New Jersey.
The time frame will be a helpful resource that ties together
much of the other information I’ve found. The
information seems reliable and well studied before writing the
website.
UniProt. 2002. Cuscuta pentagona (fiveangled
dodder).
This site is for reference as to the
classification of Cuscuta pentagona. The
taxonomy is very specifically laid out for each level and sublevel.
There are other useful websites linked to this page that have
pictures and information about Cuscuta pentagona.
This is useful as a cross reference when used along with
other sources. This website is home for an
organization that maps protein sequencing. The
taxonomy follows this purpose quite closely.
USDA, NRCS. 2012. Cuscuta pentagona Englem.
five angled dodder. The PLANTS Database (http://plants.usda.gov).
National Plant Data Team, Greensboro, NC 27401-4901 USA.
This profile of Cuscuta pentagona by the USDA
gives general background information about this plant.
A map with distribution is shown, along with Cuscuta
pentagona’s status in certain states and areas.
For example, Cuscuta pentagona is considered a noxious weed in many
states, but is considered endangered in two as well.
The phylogeny for Cuscuta pentagona is given with abbreviated
explanations. The distribution map is valuable
for determining the habitat of Cuscuta pentagona.
This website is trustworthy as the NCRS database should be up to
date and correct.
Click here to see more organisms
Multipleorganisms.net.