BACKGROUND Agave inaequidens and A. hookeri are anciently used species for producing the fermented beverage 'pulque', food and fiber in central Mexico. A. inaequidens is wild and cultivated and A. hookeri only cultivated, A. inaequidens being its putative wild relative. We analysed purposes and mechanisms of artificial selection and phenotypic divergences between wild and managed populations of...

Black walnut (Jug/am nigra L.) seeds are large and require stratification for germination. However, many seeds fail to germinate following stratification. Radiography can be used to select empty seeds, but cannot determine which full seeds will germinate. The objective of this study was to determine if any discrimination could bc achieved through use of nuclear magnetic resonance (NMR) spectros...

The regeneration of plant communities from seed depends, to a large extent, on the capacity of the seed remaining viable in the soil. The viability and germination of artificially buried Psychotria vellosiana seeds in cerrado soil were studied, with the purpose of discovering some physio-ecological aspects of dispersed seeds and evaluating their potential to constitute a soil seed bank. Seed sa...

Seeds are under strong pressure from seed predators. Therefore any physical seed trait increasing the chances of the seed’s survival should undergo positive selection. Seed color polymorphism, varying from pale to dark seeds, occurs in Scots pine (Pinus sylvestris), a keystone species of coniferous forests in Eurasia. This phenomenon can be explained by the production of large quantities of emp...

The exotic vine Vincetoxicum rossicum (Kleopow) Barbar. (Asclepiadaceae) is a major natural-areas pest throughout the Great Lakes Basin. Colonization of new areas by this herbaceous perennial occurs by comose wind-dispersed seeds. Previous experiments suggested a trade-off between seed dispersability and seed quality: smaller seeds dispersed farther but were less likely to emerge and seedlings ...

Time-dependent aftereffect induced by γ-radiation in dry pea seeds at non-lethal 0.19–10 Gy doses is considered. By using phosphorescence at room temperature (RTP), seed lot was fractionated to strong and weak seeds producing normal and abnormal seedlings, respectively, and to dead seeds. After 0.19 Gy γ-radiation, strong seeds transformed to weak seeds during two months, whereas seeds after 7–...

Irradiated pollen technique is the most successful haploidization technique within Cucurbitaceae. After harvesting of fruits pollinated with irradiated pollen, classical method called as "inspecting the seeds one by one" is used to find haploid embryos in the seeds. In this study, different methods were used to extract the embryos more easily, quickly, economically, and effectively. "Inspecting...

Seed size is a plastic trait of the plants that directly affect seed germination and seedling recruitment. This study aimed to investigate the relationship between seed size, seed germinability and seedling performance of Copaifera langsdorffii by testing four hypotheses: 1) larger seeds have higher germination percentage; 2) smaller seeds require less time to germinate and for initial developm...