Use of artificially-induced freezing temperatures to identify freeze tolerance in above-ground buds of Saccharum and Erianthus accessions

Sugarcane is a crop which is primarily grown between 30°N and 30°S latitude in tropical environments. Small areas of production in sub-tropical regions exist, and there is an increasing desire to produce the crop in colder environments. Cold-tolerant sugarcane is important both to the sub-tropical sugarcane industries and potential biofuels producers who seek to use sugarcane as a feedstock. Selection for this trait under natural conditions is difficult in sugarcane growing regions because damaging freezes are sporadic. The objective of this study was to identify sugarcane accessions for use in introgression breeding which have above-ground buds that are tolerant to freezing conditions. Above-ground (stalk) buds of 63 Saccharum, and 4 Erianthus accessions were frozen for 6 days at ?7 °C, and germinated buds were counted three weeks post-treatment. Accessions which had more bud cold tolerance than the Louisiana commercial cultivar ‘L 97-128’ were MPTH97-213, SES114, Guangxi87-22 and SES234A. Heritability estimates for percent reduction in bud germination and height of the shoots following freeze treatment was 0.47 and 0.49, respectively. Identified clones will be used in future breeding efforts at the United States Department of Agriculture, Agricultural Research Service, Sugarcane Research Unit in Houma, LA, USA.