Creation and evaluation of novel cold tolerant Miscanthus hybrids

Abstract

Miscanthus spp. have a broad geographic distribution with high levels of adaptation to different climates and edaphic conditions. This diversity can be a valuable resource for the development of miscanthus as an energy crop. Among crops with C4 photosynthesis, miscanthus is one of the most cold tolerant. Still, in cool temperate climates miscanthus develops slowly in spring, and growth is restricted during cold spells. Our aim was to screen breeding material for cold tolerance in order to select genotypes to extend the area in which miscanthus can be grown. Novel Miscanthus hybrids were created via crossings of M. sinensis × M. sinensis, M. sinensis × M. lutarioriparius, and M. sinensis × M. sacchariflorus. 2600 hybrids were created. The crosses were made from 2012 until 2014 and roughly 1700 offspring plants were transferred to the field in 2014 and 2015. Of the 826 plants planted in Denmark in 2014, 91 % survived the first winter. In Ireland 79 % of the 816 plants survived. A total of 881 offspring from M. sinensis × M. sacchariflorus were grown in the greenhouse and measured for chlorophyll fluorescence during cold treatments in growth chambers. There was a large variation between genotypes, and the Fv/Fm parameter varied between 0.825 and 0.439 when measured at 12 °C and between 0.741 and 0.315 at 8 °C. Higher mean Fv/Fm was measured on seedlings from seeds harvested from M. sacchariflorus than on seedlings from M. sinensis mothers, indicating participation of the maternal cytoplasm in the hereditability of this trait. A total of 33 hybrids with high Fv/Fm values were selected for further evaluation and have been planted in the field in order to test their phenotypic performance.