Amplified Fragment Length Polymorphism-Based Genetic Relationships Among Weedy Amaranthus Species

Abstract

Weedy Amaranthus species frequently cause economically significant reductions in crop yields. Accurate identification of Amaranthus species is important for efficient weed control, but Amaranthus species can interbreed, which might cause difficulty when identifying hybrid-derived specimens. To determine which of several economically important weedy Amaranthus species are most genetically similar, and thus most likely to produce viable hybrids, we performed amplified fragment length polymorphism (AFLP)-based unweighted pair group method with arithmetic mean (UPGMA) analysis on 8 of these species, with 141 specimens representing 98 accessions. The analysis grouped the specimens into four principal clusters composed of Palmer amaranth (Amaranthus palmeri S. Wats.) and spiny amaranth (Amaranthus spinosus L.); Powell amaranth (Amaranthus powellii S. Wats.), redroot pigweed (Amaranthus retroflexus L.), and smooth pigweed (Amaranthus hybridus L.); waterhemp (Amaranthus tuberculatus (Moq.) Sauer) and sandhills amaranth (Amaranthus arenicola I.M. Johnst.); and tumble pigweed (Amaranthus albus L.). The cluster analysis provided evidence suggesting hybridization among Powell amaranth, redroot pigweed, and smooth pigweed. Further investigations using molecular analysis of the ribosomal internal transcribed spacer region from atypical plants supported this notion. Three species, Palmer amaranth, sandhills amaranth, and waterhemp, are dioecious; nevertheless, the Palmer amaranth and waterhemp-sandhills amaranth clusters were distinct from each other. The Palmer amaranth-spiny amaranth cluster included a cluster of Palmer amaranth and two clusters of spiny amaranth, a monoecious species. Thus the dioecious species Palmer amaranth and waterhemp may not necessarily hybridize with each other more readily than they would to one or more of the monoecious Amaranthus species.

Nonhybrid Progeny from Crosses of Dioecious Amaranths: Implications for Gene-Flow Research

“…However, other evidence suggests that Palmer amaranth may be more closely related to the monoecious spiny amaranth (A. spinosus L.). Palmer amaranth and spiny amaranth have been assigned as sister taxa in AFLP-based phylogenetic analyses (Wassom and Tranel 2005). These species have the same chromosome number of 2n ¼ 34 (Gaines et al 2012;Grant 1959a), similar genome sizes , and they share distinguishing leaf and pollen morphological characteristics (Franssen et al 2001).…”

Using of Inter Microsatellite Polymorphism to evaluate gamma-irradiated<br>Amaranth mutants

“…Different molecular markers including random amplified polymorphic DNA (RAPD), simple sequence repeat (SSR) and amplified fragment length polymorphism (ALFP) have been used for more accurate study of genetic diversity and phylogenetic relationships between Amaranthus species (Xu and Sun 2001;Bež o, 2002, 2003;Wassom and Tranel 2005;Lee et al, 2008;Ray et al, 2008;Popa et al, 2010).…”

Evaluation of Genetic Structure of Amaranth Accessions from the United States

“…Many molecular markers have been used to analyze diversity, such as restriction fragment length polymorphisms (RFLPs), amplified fragment length polymorphisms (AFLPs), simple sequence repeats (SSRs), and single nucleotide polymorphisms (SNPs; Bao et al, 2006;Cheng et al, 2011;Feltus et al, 2004;Jin et al, 2010;Li et al, 2012;Liang et al, 1994;Nagaraju et al, 2002;Zhao et al, 2009). Different marker systems have been used to investigate genetic diversity (Tam et al, 2005), and random amplified polymorphic DNA (RAPD) markers and SSRs have been applied to study the genetic diversity and phylogenetic relationships among Amaranthus species (Khaing et al, 2013;Lee et al, 2008;Wassom and Tranel, 2005;Xu and Sun, 2001).…”