2012 Annual Report
1a.Objectives (from AD-416):
1. Identify a core collection of accessions from the World Collection of Sugarcane and Related Grasses that captures the greatest extent of phenotypic and molecular diversity.
2. Discover desirable alleles contributing to biomass composition in Saccharum spp through association analysis between allelic variability in candidate genes and lignocellulosic biomass components.
3. Characterize and select advanced energycane breeding lines assisted by associated markers for energy cane improvement.
1b.Approach (from AD-416):
The phenotypic and genotypic variation in the world collection of sugarcane and related grasses will be determined used to identify a core collection of accessions for association genetics and to identify genes and alleles important for breeding high biomass genoptypes.
This research relates to inhouse objective 3: Identify alleles or genes that can be used in molecular marker-assisted selection to complement the conventional approach of sugarcane.
In 2011/2012 the major progress made by ARS in this Project was in phenotyping the World Collection of Sugarcane and Related Grasses in Miami, FL to identify potential genetic sources of bioenergy. During three separate periods in April, July, and August, measurements were taken on about 850 accessions in the Miami collection for reaction to yellow leaf disease, stalk height, stalk diameter, internode length, and relative leaf chlorophyll content (SPAD, on two of the three measuring dates). In addition, ratings for stalk color, flowering, inner stalk pith, and inner stalk aerenchyma were made. On one trip, the Saccharum spontaneums in the collection were measured for Brix content. The purpose of these measurements will be to combine them with genotypic measurements being undertaken by the University of Florida team to be used for selecting about 300 accessions that represent more than 80% of the diversity in the collection. These 300 accessions will be brought to Canal Point in Years 2 and 3 of the Project for replicated agronomic testing. Key preliminary findings to date are that 18 S. spontaneums were identified with Brix values greater than 14% and 57% of the collection was resistant to yellow leaf.