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

Authors: Hale, Anna; VIATOR, RYAN - Calvin Viator & Associates; KIMBENG, COLLINS - LSU Agcenter; VEREMIS, JOHN - Animal And Plant Health Inspection Service (APHIS)

Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2016
Publication Date: 1/31/2017
Publication URL: http://handle.nal.usda.gov/10113/5642521
Citation: Hale, A.L., Viator, R.P., Kimbeng, C., Veremis, J.C. 2017. Use of artificially-induced freezing temperatures to identify freeze tolerance in above-ground buds of Saccharum and Erianthus accessions. Euphytica. 213:46. doi:10.1007/s10681-016-1826-8.

Interpretive Summary: Sugarcane is a crop that is typically grown in tropical environments; however, small areas of production in sub-tropical regions, such as Louisiana, exist. There is an increasing interest in expanding the range of adaptation of the crop to cooler climates both for sugarcane growers, and those who seek to use sugarcane as a biofuel feedstock. Erratic and unpredictable freezes make screening for this trait under natural conditions difficult. Therefore, the objective of this study was to develop an assay to identify cold tolerant sugarcane varieties and wild relatives under artificial freezing conditions, and to determine which of these varieties could contribute to increased cold tolerance in the crop through breeding efforts. Stalks of 67 wild relatives of sugarcane were frozen for six days and subsequently planted in the greenhouse to determine which ones were able to germinate following the artificially-induced freezing conditions. Three of these wild relatives, MPTH97-213, Guangxi87-22, and SES234A, were more cold tolerant than the commercial varieties that were screened. It was determined that freeze-tolerance of above-ground buds are controlled by genetic factors that can be incorporated into a breeding program, which could contribute to more cold-hardy sugarcane varieties. The developed assay identified wild relatives that are known to contribute cold tolerance to their offspring, even when grown under natural field conditions in freezing temperatures.

Technical Abstract: Sugarcane is a crop which is primarily grown between 30oN and 30oS 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 four Erianthus accessions were frozen for six days at -7oC, and germinated buds were counted three weeks post-treatment. Accessions identified 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.