干旱区生态环境知识资源中心

Drought and heat tolerant fine-leaved fescue (Festuca ssp.) grasses have potential as components in rangeland greenstrips for wildfire control in semi-arid climates, although such grasses have not been evaluated under rangeland conditions. Therefore, 63 geographically diverse Festuca accessions of 11 species were evaluated for vigor, color, and biomass in 2009 and 2010 in North Logan, UT to identify grasses for use in U.S. western rangelands. Sixty-two plants representing eight species were selected in 2009 to intermate for further evaluation. Controlled biparental matings among these selections in 2010 produced 18 populations with sufficient seed to be evaluated with three commercial Festuca checks in replicated trials between 2012 and 2013 at Malta, ID, Blue Creek, UT, and North Logan, UT, where mean annual precipitation is 265, 362, and 484 mm, respectively. Plants were evaluated for color, relative vigor, biomass, seed yield, persistence, and regrowth over 2 years. Generally, four fine-leaved populations (R4S4, R4S6, R4S22, and R4S32) with parents originating from Turkey (F. valesiaca subsp. valesiaca), Russia (F. valesiaca, F. valesiaca subsp. valesiaca), Iran (F. valesiaca), and the U.S. (F. ovina) performed equal to or better than ’Durar’ or ’Covar’ checks. In Malta (harshest environment), the performance of these four populations compared to ’Durar’ was 84-210 % for vigor, 79-90 % for color, 65-562 % for biomass, 64-296 % for seed yield, 92-117 % for persistence, and 164-454 % for regrowth, where R4S22 was superior. AFLP analysis indicated that all four populations were distinct, and that R4S4 and R4S6 grouped near ’Covar’, R4S22 clustered near ’Black Sheep’ and ’Durar’, and R4S32 was genetically unique. These populations exhibit drought tolerance and green leaf color under harsh U.S. western desert conditions that make them amendable for use in greenstrips for wildfire control.