Pearen, J. R., Pahl, M. D., Wolynetz, M. S. and Hermesh, R. 1997. Association of salt tolerance at seedling emergence with adult plant performance in slender wheatgrass. Can. J. Plant Sci. 77: 81-89. Regrowth of 15 slender wheatgrass (SWG, Elymus trachycalus sp. trachycalus (= Agropyron trachycaulum Link Malte) lines was evaluated after 3 (harvest-one) and 11 wk (harvesttwo) after clipping at four salinity levels. Lines were previously categorized into salt-tolerant (TOL) and non salt-tolerant (NT) accessions based on percent emergence at 15 mS cm -1 relative to a salt-tolerant control, tall wheatgrass (TWG, Agropyron elongatum (Host) Beauv. [= Thinopyron ponticum (Podpera) Lu & Wong]. Regrowth of five TOL, five NT, five untested (UT) SWG lines and TWG were compared in a greenhouse with nutrient solutions salinized to EC e values of 2, 7, 15, and 23 mS cm -1 . Regrowth of all SWG lines decreased from 68 to 98% as salinity increased. Orbit tall wheatgrass shoots were about threefold larger than SWG shoots at 15 and 23 mS cm -1 . Phenological development of NT lines was slower (P ≤ 0.05) than that of TOL and UT lines at all EC e levels. However, shoot growth of NT lines exceeded (P ≤ 0.05) that of TOL lines at 23 mS cm -1 . Regrowth after 3 and 11 wk were correlated within EC e levels, (r = 0.22 to r = 0.34, P ≤ 0.01). Lack of a positive relationship between lines selected for emergence in saline media and their subsequent growth under saline conditions indicates that improvements in adult plant growth under saline conditions will require additional selection for appropriate traits in SWG. A tous les niveaux de EC e , le développement phénologique des lignées non tolérantes était plus lent (≤ 0,05) que celui des lignées non tolérantes ou non testées. Toutefois, la croissance des pousses des lignées non tolérantes dépas-sait (≤ 0,05) celle des lignées tol à 23 mS cm -1 . Pour chaque niveau de salinité (EC e ), on relevait une corrélation entre la repousse à trois et celle à 11 semaines après la précoupe (r = 0,22 à r = 0,34, P ≤ 0,01). L'absence de rapport net entre les lignées sélec-tionnées sur le pourcentage de levée en milieu salin et leur croissance subséquente en conditions salines laisse à penser que l'amélioration de la croissance au stade adulte dans ces conditions demandera une sélection plus ciblée sur les composantes significatives de la croissance chez l'élyme élancé.

It is important to understand the seed system, whether you are purchasing, growing or marketing native seed. In Canada, the handling and sale of native plant seed falls under the Canadian Seeds Act and Regulations (1996). Seed is sold either as certified seed designated as to cultivar and species, or as common seed designated only to species. A cultivar, also called a named variety, has undergone selection and development for improved agronomic traits such as ease of establishment or increased yield. Cultivars are structurally distinct and have documented performance records. Their genetic character is maintained by plant breeders through the production of breeder seed. Thus, matiy etKl-us^^^p redictable than seed from wild harvest. Pedigreed seed always refers to a specific cultivar and is broken down into the following seed classifications: breeder, foundation, registered or certified. Bags of pedigreed seed are labelled with an official seed tag. Seed crops for each of these classes are produced under contract and must satisfy strict regulations for isolation distances and cropping history. They also have to meet high standards regarding genetic integrity, germination and purity (freedom from weed seeds, other crop kinds and inert matter). For specific regulations regarding the production of pedigreed seed, refer to Circular 6-94, Regulations and Procedures for Pedigreed Crop Production, published by the Canadian Seed Growers Association. This provides intermediate classification levels between seeds collected from the wild or derived from wild stock (source-identified) and classical cultivar designations. For many native plant species, Canadian cultivars or local seed sources do not exist. American cultivars are frequently imported and often sold as common seed in Canada. Many research institutions in Canada are currently developing ecological cultivars or "ecovars" of our own native plants that attempt to emphasize genetic diversity, specific adaptation and agronomic characteristics that satisfy current Canadian criteria for pedigreed status. Collecting Seed

The effect of temperature and photoperiod on primary floral induction in three lines of alpine bluegrass. Can. J. Plant Sci. 77: 615-622. The effects of temperature and photoperiod on primary floral induction in three lines of alpine bluegrass (Poa alpina L.) were studied in controlled environments. These lines were developed at the Alberta Environmental Centre from single plant accessions collected from the Alberta Rocky Mountains. Plants representing all three lines were subjected to temperatures of 3, 9, and 12°C under dark (0 h), short-day (8 h), and long-day (18 h) photoperiods for durations of 6, 10, and 14 wk. Plants were subsequently transferred to conditions of 22°C/15°C, 18 h photoperiod and heading response was recorded. Primary floral induction was found to be favoured by low temperatures and/or short days with marked inhibition at 12°C. Complete dark conditions were not inductive. Six weeks of primary induction was suboptimal with only 15% of plants flowering. However, 100% of plants flowered after 10 wk of primary induction at 3°C under both long-day and short-day conditions. Differences among lines were significant for number of heading plants, number of heads per plant, time to heading, and critical induction duration. Primary induction in line 907 occurred at longer photoperiods, warmer temperatures, and in shorter durations than the other lines indicating a lesser induction requirement. Possible implications are discussed in the use of alpine bluegrass populations for revegetating disturbed mountain sites. Les différences significatives observées entre les lignées concernaient le nombre de plantes épiant, le nombre de panicules par plantes, le délai de floraison en jour et la durée d'induction critique. Chez la lignée 907, l'induction primaire survenait sous une photopériode plus longue, à des températures plus élevées et en un temps plus court que chez les autres lignées, indiquant que cette lignée aurait de moindres besoins d'induction. Les auteurs examinent la portée éventuelle de ces observations sur l'utilisation du pâturin alpin pour la remise en végétation des sites de montagne perturbés.

Pahl, M. D. 1993