Tall fescue is an important cool season turfgrass. High temperature in summer negatively affects the performance of tall fescue in transitional and warm climate zones. As global warming continues and the use of tall fescue increases as forage and turf, it is important to evaluate and identify heat tolerant accessions for breeding new tall fescue cultivars to cope with heat stress. 

PhD student SUN Xiaoyan, under the supervision of Prof. FU Jinmin from Wuhan Botanical Garden evaluated the heat tolerance of 120 tall fescue accessions originating from America, European, Africa, South Latin, and Asian in the greenhouse and growth chambers environment. In this study tall fescue accessions showed significant phenotypic variation for most of detected traits under heat stress, which indicated that selection of the germplasm would be useful. 

Three traits including turf performance, growth rate (GR) and evapotranspiration rate (ET) might be used as effective indices to estimate heat tolerance of a wide range of tall fescue germplasm. Heat tolerance of tall fescue accessions were assessed by formulating regression models based on factor analysis in greenhouse trial and growth chambers trial, respectively.  

Results suggested that accessions from subtropical monsoon climate zone exhibited better heat tolerance. In contrast, most of accessions from East Asia showed heat sensitive. Top five heat tolerant accessions including PI 598574, PI 608787, PI 559374, Pure Gold and PI527504 were selected as a genetic resource for breeding cultivars adapted to heat stress. Furthermore, these heat tolerant accessions that combined with selected heat sensitive accessions would develop mapping populations for genome studies of heat tolerance in tall fescue. 

This research was supported by the General Program from the National Natural Science Foundation of China, the National High Technology Research and Development Program from ‘‘863’’ plan of China, and the Special Fund of Industrial (Agriculture) Research for Public Welfare of China. Results entitled “Evaluation of genotypic variation in heat tolerance of tall fescue by functional traits” were published in Euphytica (DOI 10.1007/s10681-014-1122-4) online.  

Tall fescue germplasm with heat sensitivity and heat tolerance (Image by SUN Xiaoyan)