Seed Dormancy, Seedling Establishment and Dynamics of the Soil Seed Bank of Stipa bungeana (Poaceae) on the Loess Plateau of Northwestern China

Abstract

Studying seed dormancy and its consequent effect can provide important information for vegetation restoration and management. The present study investigated seed dormancy, seedling emergence and seed survival in the soil seed bank of Stipa bungeana, a grass species used in restoration of degraded land on the Loess Plateau in northwest China. Dormancy of fresh seeds was determined by incubation of seeds over a range of temperatures in both light and dark. Seed germination was evaluated after mechanical removal of palea and lemma (hulls), chemical scarification and dry storage. Fresh and one-year-stored seeds were sown in the field, and seedling emergence was monitored weekly for 8 weeks. Furthermore, seeds were buried at different soil depths, and then retrieved every 1 or 2 months to determine seed dormancy and seed viability in the laboratory. Fresh seeds (caryopses enclosed by palea and lemma) had non-deep physiological dormancy. Removal of palea and lemma, chemical scarification, dry storage (afterripening), gibberellin (GA3) and potassium nitrate (KNO3) significantly improved germination. Dormancy was completely released by removal of the hulls, but seeds on which hulls were put back to their original position germinated to only 46%. Pretreatment of seeds with a 30% NaOH solution for 60 min increased germination from 25% to 82%. Speed of seedling emergence from fresh seeds was significantly lower than that of seeds stored for 1 year. However, final percentage of seedling emergence did not differ significantly for seeds sown at depths of 0 and 1 cm. Most fresh seeds of S. bungeana buried in the field in early July either had germinated or lost viability by September. All seeds buried at a depth of 5 cm had lost viability after 5 months, whereas 12% and 4% seeds of those sown on the soil surface were viable after 5 and 12 months, respectively.

Comparing seeds germination of some local plant species on two hydroseeding mulches for post mining revegetation

“…The possible factor influencing these variations was seed dormancy. As reported by Hu et al (2014), the rate of seedling emergence from fresh seeds, that had non-deep physiological dormancy, was significantly lower than the seeds stored for 1 year. Another study conducted by Gasque and García-Fayos (2003) showed that the seedling emergence of the recently collected seeds (2% ± 2) was lower than those stored for two months (3% ± 4) and four months (32% ± 3).…”

Overcoming root dormancy and identifying the storage behaviour of Lilium polyphyllum seeds

“…In an earlier study on in vitro germination of L. polyphyllum seeds collected from Himalayan subalpine coniferous forest, root emergence was enhanced (91%) by treatment with 100ppm IBA (25°C in 16/8h light/dark cycle) (Dhyani et al 2014). Potassium nitrate has been used to promote germination, especially in darkness, of seeds with physiological dormancy (ISTA 2012;Hu et al 2014).…”

Effect of soil moisture during stratification on dormancy release in seeds of five common weed species

“…), Gansu Province, China. Mean annual temperature is 6.7°C, and mean annual rainfall is 400 mm, with most of it falling from July to September (Hu et al ., ). Infructescences with ripe seeds were collected from several hundred individual plants of each species and taken to the laboratory, where the seeds were separated from other plant material.…”