Genetic uniformity characterizes the invasive spread of water hyacinth (Eichhornia crassipes), a clonal aquatic plant

Abstract

Aquatic plant invasions are often associated with long-distance dispersal of vegetative propagules and prolific clonal reproduction. These reproductive features combined with genetic bottlenecks have the potential to severely limit genetic diversity in invasive populations. To investigate this question we conducted a global scale population genetic survey using amplified fragment length polymorphism markers of the world's most successful aquatic plant invader -Eichhornia crassipes (water hyacinth). We sampled 1140 ramets from 54 populations from the native (South America) and introduced range (Asia, Africa, Europe, North America, Central America and the Caribbean). Although we detected 49 clones, introduced populations exhibited very low genetic diversity and little differentiation compared with those from the native range, and approximately 80% of introduced populations were composed of a single clone. A widespread clone ('W') detected in two Peruvian populations accounted for 70.9% of the individuals sampled and dominated in 74.5% of the introduced populations. However, samples from Bangladesh and Indonesia were composed of different genotypes, implicating multiple introductions to the introduced range. Nine of 47 introduced populations contained clonal diversity suggesting that sexual recruitment occurs in some invasive sites where environmental conditions favour seedling establishment. The global patterns of genetic diversity in E. crassipes likely result from severe genetic bottlenecks during colonization and prolific clonal propagation. The prevalence of the 'W' genotype throughout the invasive range may be explained by stochastic sampling, or possibly because of pre-adaptation of the 'W' genotype to tolerate low temperatures.

Influences of clonality on plant sexual reproduction

“…A molecular study of clonal diversity in both the native and introduced range of E. crassipes supports this suggestion (28). For example, in the introduced range, 80% of the populations sampled contained a single clone, with one particular clone dominating in 74.5% of the populations sampled.…”

“…For example, in the introduced range, 80% of the populations sampled contained a single clone, with one particular clone dominating in 74.5% of the populations sampled. Thus, a strong genetic bottleneck is associated with invasion, and the mid-styled morph dominates in most populations and the short-styled morph is entirely absent from the introduced range (23,28). The function of tristyly in promoting cross-pollination clearly differs in the two Eichhornia species as a result of their contrasting clonal strategies.…”

Invasion of Water Hyacinth (<i>Eichhornia crassipes</i>) Is Associated with Decline in Macrophyte Biodiversity in an Ethiopian Rift-Valley Lake—Abaya

“…E. crassipes, seems to hold the exceptional ability to be invasive. This species has the potential to multiply aggressively through clonal means of reproduction, has high growth rate and a highly dispersive floating form [6] [7]. The ecological, social and economic impact of this invasive species is complex and multifaceted: it drastically affects the physical & chemical properties of the water by reducing temperature, pH, biological oxygen demand and nutrient level.…”

Water hyacinth (Eichhornia crassipes (Mart.): Land use/land cover changes and community-based management in east Shoa zone, Ethiopia

“…Only one FGD in Bora, composed mainly of farmers involved in irrigated crop production (tomato, onion) around Ellen Lake, informed the plant to be useful in increasing soil fertility and used as cover plant for seedling establishment and during charcoal preparation. Although, our study did not include chemical composition analysis of the plant, studies elsewhere indicated that owing to its high alkalinity (pH>9) and potentially toxic heavy metals contents would restrict its use to flowering-plants, with no allowable application to horticulture for edible vegetables [16] which requires further investigation under our context.…”