Seed Dormancy and Aging in Atra Paspalum

Abstract

Seed dormancy and aging affect maintenance of germination in storage and ultimately seedling establishment. The effects that year of harvest, heat vs. air drying seed at harvest, storage environment, and aging had on germination of ‘Suerte’ atra paspalum (Paspalum atratum Swallen) were studied. Across 5 yr, average germination of fresh seed at harvest was 0% during 0 to 7 d and 5% during 8 to 14 d of a 28‐d germination period. Total germination depended on year of harvest and ranged from 9 to 46%. Oven drying (40°C for 24 h) at harvest increased germination in 2 of 5 yr. Storing seed for 6 mo in a building with no environmental control (ambient condition) increased germination to 69% (3‐yr average) and shifted most of the germination to the first 7 d, but germination was nil after 1 yr. Germination averaged 55% at 28 d after harvest for seed stored at 3°C and changed little for up to 4 yr. Oven drying seed at harvest delayed the break in dormancy ≈1 mo compared with air drying seed. Chilling air‐dried, ambient stored seed at 3°C for 48 h before testing reduced germination at 84 d after harvest (compared with 28 d and 6 mo). Neither chilling oven‐dried seed nor heat (40°C for 24 h before testing) treatment of oven‐ and air‐dried seed affected germination. Removal of the lemma and palea at harvest resulted in 96% germination compared with 26% for intact seed. Treatment of freshly harvested seed with H2SO4 for 6 min and accelerated aging (48 h at 41°C, 100% relative humidity) increased germination from 29 to 68% and 30 to 48%, respectively. Dormancy in atra paspalum is short‐lived and should be of minor agronomic importance with fall seed harvest and spring sowing. Consideration must be given to seed storage conditions to assure viability beyond 1 yr.

Variability in germination behaviour ofPaspalum dilatatumPoir. seeds is genotype dependent

“…The average temperature of the whole dry‐storage period was lower for seeds collected in the autumn of 2011 than in the summer of 2012. Thus, higher dry‐storage temperatures may have been more effective in releasing dormancy in P. dilatatum , as has been reported for P. atratum (Kalmbacher et al ., ) and Bromus tectorum L. (Allen et al ., ). However, our results may also be due to the initial seed dormancy level at harvest, or to a harvest‐date by storage‐time interaction effect on dormancy.…”

“…acid and mechanical scarification, light and alternating temperatures (Fulbright and Flenniken, ; West and Marousky, ; Schrauf et al ., ). Dry storage increased germination of seeds of P. notatum Flüggé (Maeda et al ., ) and P. atratum Swallen (Kalmbacher et al ., ). Dry storage causes after‐ripening in several species (Foley, ), which may result in a higher sensitivity to dormancy‐breaking or germination‐inducing factors (Batlla and Benech‐Arnold, ).…”

“…Cold pre‐conditioning (pre‐chilling) has been proposed as a dormancy‐breaking treatment in P. dilatatum (Johnston and Miller, ; Schrauf et al ., ), and it has also been recommended for several other Paniceae: Panicum virgatum L. (Zarnstroff et al ., ), Andropogon gerardi Vitman (Beckman et al ., ) and Sorghastrum nutans (L.) Nash (Hsu et al ., ). Seeds of P. atratum , however, showed no increase in germination with pre‐chilling (Kalmbacher et al ., ). Moreover, Schrauf et al .…”

Variation in the development of secondary dormancy in oilseed rape genotypes under conditions of stress

“…Although no clear response to seed storage was seen in the Swedish spring genotypes (Fig. 3), the storage condition of seeds can play an important role in their subsequent germination performance (Kalmbacher et al ., 1999). Seed samples used in this work were stored in conditions ranging from laboratory shelves, in the case of the Chinese seeds, to controlled temperature seed storage facilities for the Swedish types.…”

Efecto de la temperatura y la luz en la germinación de semillas de Paspalum guenoarum

“…La mayoría de las especies de Paspalum necesitan luz para germinar, a excepción de P. atratum que germina tanto en luz como en oscuridad (Kalmbacher et al, 1999). Las restantes especies estudiadas hasta el momento: P. plicatulum (Flenniken & Fulbright, 1987) y P. dilatatum (Schrauf et al, 1995) y las incluidas en las Reglas para el Análisis de Semillas (Brasil, 1992): P. conspersum, P. notatum, P. scrobiculatum, P. urvillei, P. wettsteinii manifiestan mejor su potencial germinativo en presencia de luz.…”