Location: Tropical Crops and Germplasm ResearchTitle: Tapping the US historic sweet sorghum collection to identify biofuel germplasm
Submitted to: Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/2/2014
Publication Date: N/A
Technical Abstract: Sweet sorghum [Sorghum bicolor (L.) Moench] has gained an important role as a viable alternative to fossil fuels and a more profitable option than maize and sugarcane. Nevertheless, the actual narrow genetic base in sweet sorghum breeding programs is limiting the development of new biofuel varieties. Therefore, the identification of valuable sweet sorghum germplasm present in the National Plant Germplasm System (NPGS) collection is imperative for biofuel breeding programs. Nine hundred fifty sweet sorghum accessions present in NPGS from different countries were scrutinized for agronomically and biofuel traits to select a subset of 56 accessions. A two year replicated trial of this subset together with 15 reference accessions and two control lines (RIO and HoneyNo.2) were evaluated for biofuel traits [flowering time, plant height, fresh and dry weight, brix, volume, percent of moisture, and fermentable sugars [dinitrosalicylic method (DNS)] and disease resistance response [anthracnose (Colletotricum sublineolum) and rust (Purcina purpurea)]. Eleven accessions from United States (6), Zambia (2), Ethiopia (1), South Africa (1), and Sudan (1) scored a consistently high biofuel performance (brix = 10-18; dry matter = >100 g) across years. Twenty eight and thirteen accessions were resistant to anthracnose and rust, respectively, of which five accessions showed resistance to both diseases. Remarkably, the US cultivar PI 653616 is a valuable germplasm that combined high brix (> 16.0%), dry matter content (>100 gram per plant), and multiple disease resistance. The superior accessions identified in this study should be integrated in plant breeding programs to expand genetic diversity in order to developing of new sweet sorghum varieties for biofuel production.