Wild proso millet (Panicum miliaceum) is genetically variable and distinct from crop varieties of proso millet

Abstract

Proso millet occurs both as a crop and a weed in North America. In 1970, an olive-black seeded biotype called ‘wild proso millet’ was found as an aggressive weed in row crops in Minnesota and Wisconsin and has since spread over a large area. We used Random Amplified Polymorphic DNA (RAPD) to assess genetic relationships among biotypes, measure genetic variation within wild proso millet across its range, and detect hybridization between wild proso millet and crop biotypes of proso millet. We found 97 RAPD genotypes among 398 individuals: 69 wild proso millet genotypes, 26 crop and crop-like weed genotypes, and two hybrid genotypes. Five RAPD markers consistently differentiated wild proso millet from crop cultivars and crop-like weeds. About 10% of the genotypes had at least one marker of the other type, suggesting possible hybridization between wild proso millet and crop biotypes. Most genotypes occurred in only one or two of the over 100 populations tested. The most widespread wild proso millet genotype occurred in 12 populations distributed in North Dakota, Minnesota, Illinois, and Wisconsin. More genetic variation exists among populations of wild proso millet than expected for a plant that presumably experienced a severe genetic bottleneck only 20 generations ago. Hypermutation rates and crossing between wild proso millet and crop cultivars could not account for the degree of genetic variation found in wild proso millet. The pattern of genetic variation among wild proso millet populations suggests multiple introductions of wild proso millet to North America.

Proso Millet (Panicum miliaceum L.) and Its Potential for Cultivation in the Pacific Northwest, U.S.: A Review

“…Scientists have examined the genetic diversity of proso millet accessions to investigate the genetic relationships among landraces, breeding lines and cultivars, construct phylogenetic trees and draw connections between genetic diversity and geographical origins. Several types of molecular markers have been used to estimate genetic diversity and relatedness in P. miliaceum accessions, including amplified fragment length polymorphism (AFLP) (Karam et al, 2004, 2006), random amplified polymorphic DNA (RAPD) (M’Ribu and Hilu, 1994; Colosi and Schaal, 1997), cleaved amplified polymorphic DNA (CAP) (Lágler et al, 2005), inter simple sequence repeats (ISSR) (Lágler et al, 2005; Trivedi et al, 2015), sequence related amplified polymorphism (SRAP) (Trivedi et al, 2015) and simple sequence repeat (SSR) polymorphic markers (Hu et al, 2009; Cho et al, 2010; Hunt et al, 2010, 2011; Rajput et al, 2014; Dvořáková et al, 2015; Rajput and Santra, 2016). More genetic diversity studies using SSR markers have been conducted compared to other PCR-based markers because SSR markers are (1) neutral, abundant, and evenly distributed in the genome; (2) more informative since they are co-dominant, multi-allelic, and have high polymorphic information (PIC); and (3) easier to reproduce and score (Rajput et al, 2014).…”

Morphological and molecular analysis of common millet (P. miliaceum) cultivars compared to an aDNA sample from the 15th century (Hungary)

“…The shape and structure of panicles comprise three main types in common millet (Colosi & Schaal, 1997;Scholz & Mikolas, 1991). The 20 studied cultivars in- Figure 5.…”

Biology and survival of broom corn millet (<i>Panicum miliaceum</i>) seed

“…Broom corn millet (Panicum miliaceum) is a grain crop widely grown through the northern hemisphere and known as proso-millet in USA and elsewhere. In 1970 a black seeded biotype of this species appeared in the Midwest of USA (Colosi & Schaal 1997). It quickly became weedy and was called wild proso-millet (Harvey 1979).…”