Tuesday, August 3, 2010

PS 46-166: Ecotypic variations in reproductive properties of Festuca halli

Rakhi Palit1, Yuguang Bai1, and Richard St. Pierre2. (1) University of Saskatchewan, (2) Agriculture and Agri Food of Canada

Background/Question/Methods Festuca hallii (Vasey) Piper is a native perennial grass in Western Canada. There has been an increasing demand for seeds of this species for habitats restoration and forage production, but seed production in native prairies occurs only once every 5-10 years. Preliminary analysis on the relationship between weather pattern and reproductive success indicates that fall and/or spring temperature and/or moisture conditions may be related to the transformation of vegetative shoots to reproductive shoots. The objective of this study was to determine the morphological and phenological diversity and characteristics related to seed production among selected ecotypes of F. hallii from the Fescue Prairie of Western Canada. Seeds were collected from six sites in Saskatchewan and Manitoba and sowed in the field near Saskatoon. Seedlings were transplanted from field to a greenhouse in early winter. The majority of seedlings did not reach the reproductive stage after three months of growth in the greenhouse, indicating natural vernalization was not sufficient to induce seed production. Therefore, they were subjected to artificial vernalization treatment in growth chambers.

Results/Conclusions

Five of the six collections produced seeds after artificial vernalization treatment with the percent of seed-producing seedlings from 6 to 40 % and the number of seeds per plant from 6 to 52 among ecotypes.  The ecotype from a site outside the zonal distribution range with a higher annual mean temperature and lower annual precipitation did not produce any seeds.  Variations in morphological and growth attributes among ecotypes were found such as the number of vegetative tillers per plant, leaf size, aboveground/belowground biomass, and seed mass. Seed mass was negatively correlated with aboveground biomass (r = -0.536). Differences in the morphological and phenological characteristics among ecotypes suggested strong adaptation to local environmental conditions. Different treatments are recommended for the ecotypes to improve seed production of F. hallii.