Location: Crop Germplasm Research
Project Number: 3091-21000-045-01-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2015
End Date: Aug 31, 2020
The objective of this cooperative research project is to create and characterize novel induced polyploid germplasm of selected accessions and hybrids (interspecific and intergeneric) belonging to different species and genera for the improvement of targeted warm-season grasses for bioenergy and forage purposes.
Seed of diploid Sorghum bicolor, diploid S. propinquum, other selected diploid species to be used in the hybridization program, and subsequent diploid hybrids recovered from the crosses will be treated with colchicine to double their chromosomes. The seed will be exposed to different concentrations of colchicine as well as several different adjuvants to enhance the effectiveness of the colchicine treatment. The seed will further be exposed to the various treatments over different time frames to determine which is the most effective. Once the most successful protocol is established, additional seed of the different species/hybrids will be treated using that protocol. All seedlings recovered will be transplanted into pots in a greenhouse, and the ploidy level of these plants will be determined by measuring their DNA content using flow cytometry. When necessary, their chromosome number will be determined by microscopically counting the number in their root tips. The plants identified as induced tetraploids will be checked for diploid and tetraploid sectors (chimeras) and seed will be harvested from the tetraploid sectors to recover completely tetraploid individuals. Previously developed expressed-sequence-tag-simple-sequence-repeats (EST-SSRs) from DNA sequences will be used to screen and identify informative markers for germplasm of S. propinquum and other species within the genera Pennisetum, Paspalum, and others. These markers will be used to identify hybrids when any of these species were used as the paternal parent in a cross.