Molecular markers prove to be an invaluable tool in assessing the introduction dynamics, pattern of range expansion, and population genetics of an invasive species. Ventenata dubia (Leers) Coss. (Aveneae; ventenata) is a diploid, primarily self-pollinating, annual grass native to Eurasia and Northern Africa. The grass has a detailed herbarium collection history in the western United States since its discovery in eastern Washington in 1952. Genetic analysis of 51 invasive populations (1636 individuals) of V. dubia, coupled with historical records, suggests moderate propagule pressure from multiple introductions, followed by local or regional range expansion. Allozyme analysis detected nine multilocus genotypes (MLGs) across eight western US states. A single MLG, referred to as the most common genotype, was detected in 37 of 51 (72.5%) invasive populations across all states. The other eight MLGs were generally found in fewer populations, with limited geographic distributions. Despite multiple introductions, invasive populations exhibit low levels of genetic admixture, low levels of genetic diversity within populations (A = 1.03, %P = 2.94, Hexp = 0.007) and high genetic differentiation among populations (G_ST= 0.864). The apparent reduced evolutionary potential of most V. dubia populations did not preclude the initial establishment and rapid spread of this species across its new range in the western US.

事实证明，分子标记是评估入侵物种的引入动态，范围扩展模式和种群遗传学的宝贵工具。Ventenata dubia（Leers）Coss。（Aveneae; ventenata）是一种二倍体，主要自花授粉，一年生于欧亚大陆和北非。自1952年在华盛顿东部发现草以来，该草在美国西部具有详细的植物标本室收集历史。对V的51个入侵种群（1636个个体）进行了遗传分析。杜比亚再加上历史记录，表明多次引入有适度的繁殖压力，随后局部或区域范围扩大。同工酶分析检测到美国西部八个州的九个多基因座基因型（MLG）。在所有州的51个（72.5％）侵袭人口中，有37个（72.5％）被检出了一种称为最常见基因型的MLG。通常发现其他八个MLG的人口较少，地理分布有限。尽管进行了多次介绍，但入侵种群仍表现出低水平的遗传混合，种群内较低的遗传多样性（A = 1.03，％P = 2.94，Hexp = 0.007）以及种群之间的高度遗传分化（G _ST = 0.864）。大多数V的表观降低的进化潜能。杜比亚 种群数量并不排除该物种在美国西部新范围内的最初建立和迅速传播。