Different requirements for physical dormancy release in two populations of Sophora alopecuroides relation to burial depth

Abstract

Most species of Fabaceae produce seeds with physical dormancy which was broken by some environmental factors in the field, yet for the mechanism of physical dormancy release in the natural condition is still poorly understood. In present study, seeds of Sophora alopecuroides from two populations were placed on the soil surface or buried at depths of 2 and 7 cm in the field and were exhumed at time intervals to assess the changes of dormancy. Also, microenvironments were simulated in the laboratory to determine the possible components (temperature, temperature fluctuation, and moisture) involved in physical dormancy release. The laboratory work indicated that wet heat is an important dormancy release mechanism for both populations; and dry heat for one of them, but showed no effects on the other one. Consistent with that, burial experiment showed seeds of two populations had two contrasting-dormancy release patterns in the field. Most seeds of the dry heat sensitive population released dormancy but the other one remained dormant when seeds placed on the soil surface for 11 months (where seeds were exposed to dry heat but not wet heat). The difference of physical dormancy release pattern response to burial depth and simulated condition may attribute to seed coat color and hilum thickness which showed significantly different between two populations. This conclusion may improve understanding of physical dormancy release mechanism among populations and have a practical use for grassland management and weed control.

Seed dormancy-breaking in a cold desert shrub in relation to sand temperature and moisture

“…Variation in temperature and substrate moisture content among different burial periods and depths are considered key factors that influence PY-breaking in natural conditions (Norman et al 2002; Van Klinken et al 2006, 2008; Hu et al 2009). However, substrate moisture does not seem to play an important role in modulating PY- break of E. songoricum seeds under natural conditions.…”

“…As burial depth increases, the rate of PY release may decrease (Taylor and Ewing 1988; Van Klinken and Flack 2005; Van Klinken et al 2006), increase (Hu et al 2009) or increase and then decrease (Loi et al 1999; Zeng et al 2005). Burial depth is closely related to soil temperature and moisture.…”

Effect of water availability and seed source on physical dormancy break of Vicia villosa ssp. villosa

“…fire exposure) or alternating soil wetting/drying cycles (Hu et al, 2009;Santana et al, 2010). fire exposure) or alternating soil wetting/drying cycles (Hu et al, 2009;Santana et al, 2010).…”

“…Seed stratification after seed maturity is cited as a successful PY-break treatment for V. grandiflora Scop., V. cracca L., V. hirsuta L. (Gray), V. bythinica L. and V. ervilia L. Willd. Interspecific variability in response might be a result of life form (perennial, winter or summer annual) or adaptation to a local environment (Grime et al, 1981;Hu et al, 2009). Conversely, PY break of V. villosa generally occurs by exposure to high temperatures (i.e.…”

Breaking Physical Dormancy of the Laburnum anagyroides Seeds by in vivo and in vitro Conditions

“…Среди них немало ценных сель-скохозяйственных, декоративных и экономически важных культур. Видовые особенности физического покоя семян во многом зависят от жизненной формы растения и его адаптации к условиям про-израстания [2][3][4].…”