Emergence of temperate pasture grases from different sowing depths: importance of seed weight, coleoptiele plus mesocotyl length and shoot strength

Abstract

Inter-specific relationships between mean seed weight, coleoptile + mesocotyl (sub-coleoptile internode) length and width, shoot strength and emergence from different sowing depths were examined for timothy (Phleum pratense L., mean seed weight 0.33-0.48 mg depending on seed line), cocksfoot (Dactylis glomerata L., 0.65-0.78 mg), perennial ryegrass (Lolium perenne L., 1.7 1-2.19 mg), tall fescue (Festuca arundinacea Schreb., 1.73-2.60 mg), annual ryegrass (Lolium multijlorum Lam., 5.10-5.20 mg) and prairie grass (Bromus willdenowii Kunth., 10.5-12.2 mg). Across species at 10, 30 and 60 mm sowing depths in the field and 10, 15 and 30 mm sowing depths under controlled environment conditions, there was a significant (P < 0.05) positive correlation between emergence % and mean seed weight. Across species at 10-30 mm sowing depth under controlled environment conditions, emergence % was not significantly correlated with coleoptile + mesocotyl length but there were significant positive correlations between emergence % and coleoptile and mesocotyl width: shoot strength increased with increased coleoptile width across species. For seed lines of timothy of different mean seed weight (0.21-0.81 mg), emergence %, coleoptile + mesocotyl length and coleoptile and mesocotyl width increased with increased seed weight at 10 and 15 mm sowing depth. Shoot strength increased with increased coleoptile width for timothy. For emerged and non-emerged cocksfoot and timothy seedlings regardless of seed weight, mean coleoptile + mesocotyl length was > 10 mm at 10 mm sowing depth. It is concluded that at 10-30 mm sowing depth, increased emergence % with increased seed weight across species is not due to increased coleoptile + mesocotyl length. It is proposed that increased emergence % with increased seed weight across species at 10-30 mm sowing depths and across seed lines of timothy at 10 mm sowing depth is primarily due to increased coleoptile and mesocotyl width resulting in increased shoot strength and hence an increased ability to penetrate the substrate.

The effects of ploidy and seed mass on the emergence and early vigour of perennial ryegrass (Lolium perenne L.) cultivars

“…Shoot characteristics such as coleoptile tiller development (Lewis and Garcia 1979) and coleoptile and mesocotyl length and thickness (Andrews et al 1997) have been shown to be important characteristics related to the early vigour of forage grass species, especially in stress environments. Our data demonstrate that when seed mass effects are removed there is still considerable variation for a range of seedling vigour components in perennial ryegrass cultivars.…”

Relationship Between Emergence and Genome Content of Iranian Tall Fescue Entries Under Drought Stress

“…As a result, root growth is probably a better indicator of establishment and survival than leaf growth in tall fescue under drought conditions. In cool-season grass species, quick emergence depends on factors associated with the genotypes, the germination environment, and seed characteristics (Gazanchian et al 2006;Mut and Aka 2010) including seed dormancy, seed reserves, and seed weight (Andrews et al 2008). It is well known that rapid and complete germination are important during the establishment of grass species (Mut and Aka 2010;Larsen and Bibby 2004).…”

The merits of artificial selection for the development of restoration‐ready plant materials of native perennial grasses

“…Berdahl and Barker () found that field emergence of Russian wildrye was positively correlated with both coleoptile length ( r = 0.51–0.64; p < 0.01) and emergence from a 5‐cm‐deep greenhouse planting ( r = 0.78; p < 0.01). Andrews et al () reported that coleoptile width is positively correlated with both emergence percentage ( r = 0.97) and shoot strength ( r = 0.93) across grass species (Table ). In addition, Larson et al () reported that coleoptile tissue density (dry‐matter percentage) is negatively correlated with emergence across grass species (Table ).…”