TITLE:
Morphological Characterization of Amaranthus palmeri x A. spinosus Hybrids
AUTHORS:
William T. Molin, Vijay K. Nandula
KEYWORDS:
Herbicide, Hybrid, Palmer Amaranth, Resistance, Spiny Amaranth
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.6,
May
27,
2017
ABSTRACT: The growth of clones of
seven Amaranthus palmeri x A. spinosus hybrids was compared to type specimens of A. palmeri and A. spinosus. The
hybrids came from the field where they were originally discovered and clones of
the type specimens and hybrids were established under greenhouse conditions and
used to compare growth rates. A. palmeri had
the highest growth rate and A. spinosus the lowest growth rate
based on height, node counts, and dry weight accumulation. A. palmeri also had the greatest
number of days to flowering and A. spinosus the fewest. Hybrids had
intermediary growth rates and days to flowering, but differed from each other
with regard to sex identity. The hybrids were either dioecious like A. palmeri or, if
monoecious, had patterns unlike A. spinosus. Spine
length and texture also varied in hybrids and some were without spines. Hybrid
16Ci was short compared to all others and had succulent leaves and stems, which
easily separated from the plant body. These hybridizations resulted in
morphologically distinct types with acquisition of physical traits intermediate
to the type specimens which may drive evolution of these species.