|Armstrong, John - Scott|
|Limaje, Ankur - Oklahoma State University|
Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2018
Publication Date: N/A
Interpretive Summary: There is a great need in the sorghum industry for new breeding lines that are sugarcane aphid (SCA) tolerant, and that exhibit high yields and favorable agronomics. In many sorghum production environments, the lack of SCA resistance means greatly reduced grain yields and harvesting complications due to the SCA. R.LBK1 and R.LBK2 are two grain sorghum lines that were developed and released by USDA scientists in Lubbock, Texas that possess excellent SCA resistance at all stages of plant development and have had high grain yields in multiple environments in Texas and Kansas. These two lines provide immediate impact to the sorghum community by providing SCA resistance in elite and diverse genetic backgrounds.
Technical Abstract: The sorghum [Sorghum bicolor (L.) Moench] germplasm lines R.LBK1 and R.LBK2 (R.LBK1, PI 687244; R.LBK2, PI 687245) were developed and released by the United States Department of Agriculture in Lubbock, TX, in 2017 because of their high degree of resistance to the sugarcane aphid (SCA) [Melanaphis Sachari (Zehntner) (Hemiptera: Aphidae)]. Both lines were developed using the pedigree method of plant breeding and are confirmed to be restorer lines. The breeding crosses for both lines were made in Lubbock, TX, and selections were made in Lubbock, TX, and Corpus Christi, TX. Evaluation for SCA resistance was conducted in two field locations in Texas in 2016, as well as a greenhouse experiment at the USDA-ARS laboratory in Lubbock TX. Both lines express strong resistance to SCA pressures at both seedling and mature plant stages. Preliminary hybrids using highly susceptible seed parents (A-lines) have also shown strong resistance to SCA, indicating that the resistance is dominantly expressed in F1 hybrids using these two lines. R.LBK1 and R.LBK2 are not completely immune to the SCA, but damage is greatly reduced and resistance is drastically apparent when compared to other susceptible sorghum lines and hybrids. These lines provide much needed resistance to the SCA, and are suitable as germplasm in a plant breeding program or as parental lines for hybrid development.