A fundamental goal of plant population ecology is to understand the consequences for plant fitness of seed dispersal by animals. Theories of seed dispersal and tropical forest regeneration suggest that the advantages of seed dispersal for most plants are escape from seed predation near the parent tree and colonization of vacant sites, the locations of which are unpredictable in space and time. ...

The transition from dormancy to germination in seeds is a key physiological process during the lifecycle of plants. Abscisic acid (ABA) is the sole plant hormone known to maintain seed dormancy; it acts through a gene expression network involving the transcription factor ABSCISIC ACID INSENSITIVE 3 (ABI3). However, whether other phytohormone pathways function in the maintenance of seed dormancy...

genic crops is considered a major threat to the durability of these crops (van Rie, 1991; Gould, 1994; McGaughey, Seed mixtures are recommended as a strategy to minimize or avoid 1994). Refugia in the form of susceptible (nontranshaving insects develop resistance to insect-resistant transgenic crops. genic) plants to prevent exposure of some portion of The objective of this study was to evaluat...

Seed mass and relative growth rate (RGR) are important determinants of early seedling growth, and hence seedling establishment. Although a positive interspecific relationship between seed mass and seedling dry mass is well established, much less is known about the relationships among seed mass, seedling mass and RGR within species. We examined relationships among seed mass, seedling mass and RG...

A profusion of fruit forms implies that seed dispersal plays a central role in plant ecology, yet the chance that an individual seed will ultimately produce a reproductive adult is low to infinitesimal. Extremely high variance in survival implies that variations in fruit production or transitions from seed to seedling will contribute little to population growth. The hey issue is that variance i...

Salicylic acid-deficient NahG transgenic lines and sid2 mutants were used to evaluate the role of this compound in the development of the short-lived, annual plant Arabidopsis thaliana, with a particular focus on the interplay between salicylic acid and other phytohormones. Low salicylic acid levels led to increased growth, as well as to smaller abscisic acid levels and reduced damage to PSII (...

Growth and yield of potato plants grown from several weight classes of whole "B" seed, unsorted "B" seed, and 56 g cut seed pieces were compared in Ohio in 1988 and 1989. Whole "B" seed classes were 8 g ranges with means of 35 g, 43 g, 51 g, and 58 g. Unsorted "B" seed was used as an experimental control. Treatment responses were inconsistent. Few significant differences were evident at bloom i...

Gamma-linoleic acid in the seed oil of evening primrose makes it nutritionally and pharmaceutically valuable. If evening primrose wants to be cultivated as an annual plant, sowing time is important. By the late sowing and depends to time most plants do not produce flower stem and stay in rosette stage until next spring. To solve this problem, the present study was performed. Seedling were trans...

The foundation of many plant-ant mutualisms is ant protection of plants from herbivores in exchange for food and/or shelter. While the role of symbiotic ants in protecting plants from stem- and leaf-feeding herbivores has been intensively studied, the relationship between ant defense and measures of plant fitness has seldom been quantified. We studied ant aggression, damage by herbivores and se...

Flowering is a crucial determinant for plant reproductive success and seed-set. Increasing temperature and elevated carbon-dioxide (e[CO2]) are key climate change factors that could affect plant fitness and flowering related events. Addressing the effect of these environmental factors on flowering events such as time of day of anthesis (TOA) and flowering time (duration from germination till fl...