in order to investigation the effects of seed origin and planting date on yield  and essential oil of pimpinella affinis, a field experiment was carried out in alborz research center in 2007. this experiment was performed under factorial in the base of (rcbd) with three replications. the treatments were included locations of seeds collection and planting dates. essential oils were extracted fro...

The distribution and dynamics of plant populations depend on the recruitment of young individuals, which is influenced by seed production, animal seed dispersal, dispersal distance, and the deposition of seeds in favourable places for seed germination/ establishment and seedling survival. In particular, seeds dispersed over long distances will likely encounter new environmental conditions that ...

A seed is an intricate structure. Of the two development processes involved in seed formation, seed maturation, or seed program includes accumulation of storage products, acquisition of desiccation tolerance, and induction of dormancy. Little is known about how these processes were originated and integrated into the life cycle of seed plants. While previous investigation on seed origin was almo...

The aim of this thesis was to increase our knowledge about the effects of seed origin on the timing of height growth cessation and field performance of silver birch (Betula pendula Roth) from different latitudes, with special attention paid to the browsing damage by moose in young birch plantations. The effect of seed origin latitude and sowing time on timing of height growth cessation of first...

Although methods exist to identify well-defined relations, such as is_a or part_of, existing tools rarely support a user who wants to define new, domain-specific relations. We conducted a situated case study in plant science and introduce four new domain-specific relations that are of interest to domain scientists but have not been explored in information science. Results show that precision va...

Extinctions can leave species without mutualist partners and thus potentially reduce their fitness. In cases where non-native species function as mutualists, mutualism disruption associated with species' extinction may be mitigated. To assess the effectiveness of mutualist species with different origins, we conducted a meta-analysis in which we compared the effectiveness of pollination and seed...

It is generally accepted that larger seeds give rise to seedlings with better performance. On the other hand, the size that a seed reaches is genetically determined by at least two different traits ; the genetic variability of the developing embryo and the genetic variability of the maternal plant. Thus, the relative contributions of these two traits affect seedling performance by influencing s...

Water shortage is one of the most important environmental stresses in Mediterranean regions. Poor seedling quality may account for the failure of oak regeneration. To determine the best seed origin of Quercus brantii, we investigated on seedlings collected from 20 mother trees in the Zagros Mountain forests 700 to 2200 m altitudes above sea level. Seedlings from different altitudes were irrig...