Winter Hardiness and Freezing Tolerance in a Hairy Vetch Collection

Abstract

Hairy vetch (Vicia villosa Roth) is a winter‐annual legume that is grown as a cover crop and for forage. Although more winter tolerant than most leguminous winter annuals, it does not reliably overwinter in the upper Midwestern United States. Our objectives were to screen a collection of accessions for winter hardiness and develop a screening method for freezing tolerance in a controlled setting. We evaluated 30 accessions (commercial germplasm and breeding populations) in multiple Minnesota environments. Average winter survival among accessions ranged from 13 to 73% and resembled a bimodal distribution, where two distinct phenotypic groupings were apparent. Commercial VNS (variety‐not‐stated) accessions were found to be highly variable for winter survival. Seed derived from Minnesota was generally winter hardy (>65% survival), and seed from Oregon was not (<39%). Due to large variation among and within field environments, a method of controlled freezing was developed to supplement winter hardiness evaluations. No differences in freezing tolerance were found among accessions without cold acclimation. However, large differences in freezing tolerance occurred when plants were first grown for 2 wk in greenhouse conditions (22°C, 16‐h photoperiod) and then cold acclimated for 4 wk (3°C, 10‐h photoperiod). Lethal temperatures were determined from six 24‐h programmed freezing treatments, where treatment temperatures ranged from −13 to −21°C. Accessions differed significantly for freezing tolerance, with median lethal temperature values ranging from −8.4 to −16.0°C. This method of controlled freezing correlated highly with winter survival in field evaluations (ρ = 0.77).

Diversity of Naturalized Hairy Vetch (Vicia villosa Roth) Populations in Central Argentina as a Source of Potential Adaptive Traits for Breeding

“…As mentioned above, a lack of geographical signature in the pattern of population variation, as occurs with other allogamous species (Garayalde et al, 2011), can also be explained by human activities on seed dispersal and genetic drift (Knapp and Rice, 1998). Cultivated populations are openpollinated and highly heterogeneous and would be subject to natural selection and genetic drift throughout the cycles (Wiering et al, 2018). These results are consistent with observed in the phenotypic traits.…”

Estimating agronomically relevant symbiotic nitrogen fixation in green manure breeding programs

“…Due to the outcrossing nature of most legume cover crop species, the genetic units available to breeders are typically populations with high genetic heterogeneity. Other studies with hairy vetch have also found greater trait vari-ation within than among populations (Kissing Kucek et al, 2019;Wiering et al, 2018). With an outcrossing reproductive system and open-pollination, any pedigree-based analysis is limited to maternal half-sib families with uncertain paternity.…”

“…For new breeding programs aimed at improving legume green manures (Kissing Kucek et al., 2019; Kissing Kucek, Riday, et al., 2020; Moore et al., 2020), farmers identified symbiotic N fixation (SNF) as the most important trait of interest (Wayman et al., 2017). So far, new breeding programs for legume green manures have focused on removing undesirable traits like seed dormancy (Kissing Kucek, Azevedo, et al., 2020) and improving cover crop establishment, overwinter survival, and spring biomass production (Kissing Kucek et al., 2019; Wiering et al., 2018). Breeding for SNF is more complicated because the goals and strategies may differ depending on the crop species, its agronomic functions, and the environments where it is grown.…”

Lidar and RGB Image Analysis to Predict Hairy Vetch Biomass in Breeding Nurseries

“…Hairy vetch has exhibited high tolerance to winter stress (Brandsæter et al, 2008; Wiering et al, 2018) and high biomass production (Blevins et al, 1990; Teasdale et al, 2004), equating to greater fixed N 2 potential. Breeding efforts are ongoing to improve both the winter survivability and biomass yield of hairy vetch, an outcrossing species, for cover cropping in the midwestern United States (Wiering et al, 2018). Plant breeders have traditionally relied on visual approximations to phenotype biomass in vivo (Casler and van Santen, 2010) because it is nondestructive and generally time efficient.…”

“…Winter annual legume cover crops, such as hairy vetch, provide soil coverage to stabilize the topsoil and provide biologically fixed N 2 for use by subsequent crops in a rotation (Herridge and Rose, 2000). Hairy vetch has exhibited high tolerance to winter stress (Brandsæter et al, 2008; Wiering et al, 2018) and high biomass production (Blevins et al, 1990; Teasdale et al, 2004), equating to greater fixed N 2 potential. Breeding efforts are ongoing to improve both the winter survivability and biomass yield of hairy vetch, an outcrossing species, for cover cropping in the midwestern United States (Wiering et al, 2018).…”