Life Sciences Commons^™

Impacts Of Smooth Pigweed (Amaranthus Hybridus) On Cover Crops In Southern Ontario, Heather Vanvolkenburg, Frédérique C. Guinel, Liette Vasseur

Biology Faculty Publications

Amaranthus hybridus is a noxious weed in Ontario, with demonstrated allelopathic properties that can lead to decreased agricultural production. We tested the germination and growth of five cover crop species exposed to A. hybridus extracts, and to dried or fresh materials in soil. A germination index was calculated, and the dry weight of plant organs were measured to quantify responses to treatments. All species had reduced germination (≤29%) in 100% extract. Trifolium pratense had significant root weight reductions in extract (52%) and dried (72%) treatments, whereas shoot weight only decreased (48%) in dried treatment. Medicago sativa shoot weight decreased (52%) …

Assessing Seed Handling Processes To Facilitate A Community-Engaged Approach To Regional Forest Restoration, Meredith Cobb, Michaela J. Woods, Ryan Mcewan

Biology Faculty Publications

In the Midwestern United States, there is a strong management impetus toward reforestation to replace trees lost to due to tree mortality and to establish forests on previously cleared properties. Here, we describe a public outreach and volunteer effort that aimed to generate positive, community-engaged restoration outcomes and report on a practical experiment involving seed handling. We obtained tree seeds that were donated by members of the community to local land managers. We evaluated the size of the seeds collected and tested the influence of common stratification media (none, sand and vermiculite) and seed size on germination success of three …

Mobilization And Role Of Starch, Protein, And Fat Reserves During Seed Germination Of Six Wild Grassland Species, Ming Zhao, Hongxiang Zhang, Hong Yan, Lu Qiu, Carol C. Baskin

Biology Faculty Publications

Since seed reserves can influence seed germination, the quantitative and qualitative differences in seed reserves may relate to the germination characteristics of species. The purpose of our study was to evaluate the correlation between germination and seed reserves, as well as their mobilization during germination of six grassland species (Chloris virgata, Kochia scoparia, Lespedeza hedysaroides, Astragalus adsurgens, Leonurus artemisia, and Dracocephalum moldavica) and compare the results with domesticated species. We measured starch, protein, and fat content in dry seeds and the initial absorption of water during imbibition. Starch, soluble protein, fat, and soluble …

Black Cohosh Seed Germination And Conservation, W. John Hayden

Biology Faculty Publications

Like many plant enthusiasts, I have spent a considerable amount of time planting seeds. Every year I grow many vegetables—my garden always includes some annual bedding plants—and I sow seeds of cover crops (winter wheat, winter rye, and buckwheat) by the tens of thousands. While I have committed vast numbers of propagules to moist soil, I cannot say that I have watched every single one sprout. Nevertheless, I certainly have observed the germination process many, many times for lots of different seeds. For these seeds of garden plants, germination is quite rapid, just a few days to maybe as much …

Seed Germination Ecology Of The Cold Desert Annual Isatis Violascens (Brassicaceae): Two Levels Of Physiological Dormancy And Role Of The Pericarp, Yuan M. Zhou, Juan J. Lu, Dun Y. Tan, Carol C. Baskin, Jerry M. Baskin

Biology Faculty Publications

The occurrence of various species of Brassicaceae with indehiscent fruits in the cold deserts of NW China suggests that there are adaptive advantages of this trait. We hypothesized that the pericarp of the single-seeded silicles of Isatis violascens restricts embryo expansion and thus prevents germination for 1 or more years. Thus, our aim was to investigate the role of the pericarp in seed dormancy and germination of this species. The effects of afterripening, treatment with gibberellic acid (GA₃) and cold stratification on seed dormancy-break were tested using intact silicles and isolated seeds, and germination phenology was monitored in …

Seed Dormancy, Seedling Establishment And Dynamics Of The Soil Seed Bank Of Stipa Bungeana (Poaceae) On The Loess Plateau Of Northwestern China, Xiao Wen Hu, Yan Pei Wu, Xing Yu Ding, Rui Zhang, Yan Rong Wang, Jerry M. Baskin, Carol C. Baskin

Biology Faculty Publications

Studying seed dormancy and its consequent effect can provide important information for vegetation restoration and management. The present study investigated seed dormancy, seedling emergence and seed survival in the soil seed bank of Stipa bungeana, a grass species used in restoration of degraded land on the Loess Plateau in northwest China. Dormancy of fresh seeds was determined by incubation of seeds over a range of temperatures in both light and dark. Seed germination was evaluated after mechanical removal of palea and lemma (hulls), chemical scarification and dry storage. Fresh and one-year-stored seeds were sown in the field, and seedling …

Seed Dimorphism, Nutrients And Salinity Differentially Affect Seed Traits Of The Desert Halophyte Suaeda Aralocaspica Via Multiple Maternal Effects, Lei Wang, Jerry M. Baskin, Carol C. Baskin, J. Hans C. Cornelissen, Ming Dong, Zhenying Huang

Biology Faculty Publications

BACKGROUND: Maternal effects may influence a range of seed traits simultaneously and are likely to be context-dependent. Disentangling the interactions of plant phenotype and growth environment on various seed traits is important for understanding regeneration and establishment of species in natural environments. Here, we used the seed-dimorphic plant Suaeda aralocaspica to test the hypothesis that seed traits are regulated by multiple maternal effects.

RESULTS: Plants grown from brown seeds had a higher brown:black seed ratio than plants from black seeds, and germination percentage of brown seeds was higher than that of black seeds under all conditions tested. However, the coefficient …

Linking Fruit Traits To Variation In Predispersal Vertebrate Seed Predation, Insect Seed Predation, And Pathogen Attack, Noelle G. Beckman, Helene C. Muller-Landau

Biology Faculty Publications

The importance of vertebrates, invertebrates, and pathogens for plant communities has long been recognized, but their absolute and relative importance in early recruitment of multiple coexisting tropical plant species has not been quantified. Further, little is known about the relationship of fruit traits to seed mortality due to natural enemies in tropical plants. To investigate the influences of vertebrates, invertebrates, and pathogens on reproduction of seven canopy plant species varying in fruit traits, we quantified reductions in fruit development and seed germination due to vertebrates, invertebrates, and fungal pathogens through experimental removal of these enemies using canopy exclosures, insecticide, and …