Narrow‐Leaf Plantain (Plantago lanceolata L.) Selection for Increased Freezing Tolerance

Abstract

Studies in the northeastern United States have shown that the improved cultivars of narrow‐leaf plantain (Plantago lanceolata L.) do not have sufficient winter hardiness to persist under wintertime conditions typical of that region. However, an experimental line, PG700, developed from productive plants collected from the southern, mid‐Atlantic, and midwestern United States had significantly greater survival after freezing than the commercially available cultivars. A field study was initiated in 2006 to select for additional freezing tolerance in PG700. Superior materials collected after two‐years of selection pressure were evaluated in growth chambers for survival after exposure to −11 and −14°C or after exposure to drought that was severe enough to kill all visible leaves. The cultivar Tonic was included as a freezing‐susceptible control. Survival of spaced plants of PG700 in the field was high, with mortality rates of 9% following the first winter after transplanting, 26% of the remaining plants after the following summer, and 11% after the second winter. Even with the low selection pressure, progeny of plants selected after the first winter had more than twice the survival rate of the original population when exposed to −14°C. No Tonic plants survived at −14°C. PG700 did not have greater drought resistance than Tonic, nor was its drought resistance improved by the selection process. Increased freezing tolerance will increase the suitability of plantain as a component of perennial pasture mixtures in temperate regions of the United States.

Global gene flow releases invasive plants from environmental constraints on genetic diversity

“…It has been present in Australia since before 1850 (https://www.ala.org.au/), in North America since before 1832 (30), and for an unknown time in South Africa (52). It is cultivated as a commercial pasture plant in New Zealand because it grows well in the mild winter and limits soil nitrification (31). The species is classed as invasive in its nonnative range (52) because it reproduces prolifically and spreads over large areas (53).…”

Loss of plasticity in life‐history strategy associated with secondary invasion into stressful environments in invasive narrowleaf plantain (Plantago lanceolata L.)

“…The plants are vulnerable to cold sub‐zero temperatures and have been demonstrated to be killed by severe winter conditions (i.e. up to 82% mortality at −12°C; Skinner & Stewart ). The minimum temperature at the edge location can reach near this level at −9°C (Appendix ).…”

Freeze Tolerance of Perennial Ryegrass and Implications for Future Species Distribution

“…After emergence, seedling trays were moved into the controlled environment chamber. Chamber protocol followed that used by Skinner and Stewart (2014). Initial conditions comprised a diurnal temperature cycle from a maximum of 21°C at 1400 h and a minimum of 13°C at 0600 h and a corresponding relative humidity cycle from 75% at 0600 h to 50% at 1400 h. A photosynthetically active radiation level of 975 μmol m −2 s −1 was maintained for 14 h d −1 using high‐pressure sodium, metal halide, and incandescent lights.…”