. Citrus seed biology, including morphology and viability, storage conditions, and treatments to improve rate and synchrony of germination, was studied exhaustively during the 1940s and 1980s (reviewed by Castle, 1981 ). Seed behavior and physiological
; Rumbaugh et al., 1993 ). Currently, the lack of successful in and ex situ germination resulting from seed dormancy limits its use in restoration. Few sources explore the dormancy mechanisms and methods that induce germination in Sphaeralcea spp. ( Page et
associated with poor or sporadic germination might be avoided if a treatment were developed to control hypocotyl and radicle length so that previously germinated seeds could be sown mechanically and 100% stand establishment could be achieved. Several
Farmers throughout the world have traditionally used fire and smoke in grain drying practices. It is thought that these methods improve germination and seedling vigor ( Paasonen et al., 2003 ). Recently, the germination response to smoke has been
., 2000 ). For instance, RFOs accumulate during seed maturation where they are believed to form, with sucrose, a vitrified environment that stabilizes desiccated seed membranes. Upon germination, RFOs are converted rapidly to monomeric sugars ( Obendorf
( Milstein, 2005 ). Phlox pilosa is potentially useful in these situations. This species is found in all states from North Dakota to Texas and eastward into Florida and New York ( Barkley, 1986 ). Germination of P. pilosa seeds is erratic ( Specialty
Seashore paspalum (Paspalum vaginatum O. Swartz) is a perennial warm-season grass that is rapidly gaining popularity for use on golf courses and athletic fields. The first seeded cultivar of seashore paspalum was recently developed. Seed from the pilot production of this cultivar harvested in Oregon during 2002 by Turf-Seeds, Inc. demonstrated a high level of apparent seed dormancy with a tetrazolium test of 91% but a germination rate of less than 5% at room temperature. This seed was used in laboratory experiments to determine the effect of a number of environmental factors on germination response in this new turf species. Treatment factors are germination media, constant and alternating (night/day) temperatures, and light. A strong and significant effect of temperature on germination was observed. Total germination was increased at higher temperatures. At the same daytime temperature, seed germination under alternating temperature was better than germination at constant temperature. The effect of light on germination was significant at 20, 25, 30, 20/35 °C in water and at 25/35 °C in 0.2% KNO3 germination media. However, the effect of light on germination in KNO3 media was not significant at 35 °C constant and 20/30 °C alternating temperatures. Alternating temperature used in conjunction with KNO3 media reduced the requirement for light. The use of 0.2% KNO3 rather than water as the germination media increased germination in most temperature and light treatments. Based on our results, maximum germination percentage was obtained when seed was germinated at 35 °C constant or 20/35 °C alternating temperature. However, when we consider field application, 25/35 °C with light is more realistic condition in field. Therefore, recommended seed germination test condition is at 25/35 °C with KNO3 treatment.
The germination phase is an important and vulnerable stage in the life cycle of plants because establishment of the seedling and plant growth can be partly defined and seriously influenced by salinity ( Hu et al., 2012b ). Salinity stress is
Various combinations of temperature and moisture contents were used in evaluating the seed storage of nine genera of annual flowers. Relative humidity (RH) levels of 11%, 32%, 52%, and 75% provided wide ranges in seed moisture during storage at 5, 15, and 25C. At each temperature, total germination percentages (G) generally declined as seed moisture content increased during storage. The seed moisture range giving the highest G after 12 months of storage was determined for each temperature and plant genus. For all genera, seed moisture contents during storage increased as storage temperatures increased at constant RH levels. Moisture contents at 25C storage were 37%, 34%, 29%, and 20% higher than at 5C when RH levels were at 11%, 32%, 52%, and 75%, respectively.
, holds significant water in its layers, and seedlings can easily emerge through it upon germination ( Dana and Lerner, 2001 ). Walker et al. (1984) reported that watering was less frequent when a top coating was used in seed germination. A vermiculite