Location:
Project Number: 3072-21000-009-023-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 15, 2016
End Date: Sep 14, 2021
Objective:
Identify new sources of genetic resistance to sugarcane aphids (SCA), characterize the host plant resistance mechanisms and the resistance genes, and develop genetic stocks and/or varieties of sorghum lines with SCA resistance.
Approach:
We have discovered new sources of resistance to sugarcane aphid (SCA) and will continue to screen germplasm collections for additional resistance sources. Characterizing the genetic diversity of new resistance sources and determining diverse resistance mechanisms (genes or regulatory pathways) will provide sorghum improvement researchers with the knowledge to develop durable resistant varieties. Pyramiding multiple resistance genes can increase the longevity of resistance (Nelson, 1972, Ebana et al. 2015). Experiments will be initiated to (1) confirm earlier determinations on resistance traits (i.e. tolerance, antibiosis, etc.) of the newly discovered germplasm sources and (2) to identify quantitative trait loci (QTL) associated with each of the traits. Upon estimation of the degree of resistance for each trait, we will generate sorghum populations, with a combination of these resistance traits and yield potential, for inbred development using a marker-assisted selection method. We will make crosses with different resistant traits and move them into adapted backgrounds to generate genotypes combining multiple aphid resistance alleles (each controlling a different response to SCA) and test gene combinations within a homogeneous genetic line under field environments. Desirable genotypes with the best combinations of target traits will be identified, selected, and tested. We will produce new genetically improved sorghum germplasm with durable resistance to SCA. SCA resistant germplasm will be timely transferred to public and private plant breeding programs. We will monitor aphid populations biannually at all monitoring sites for possible biotypic change, which if it were to occur would impact breeding programs for SCA resistance. If biotypes develop results will be shared project wide via myfields.info and used to modify strategies for developing SCA resistant sorghum.
