Registration of Oilseed Sunflower Germplasms HA 482, RHA 483, and RHA 484 Selected for Resistance to Sclerotinia and Phomopsis Diseases

Abstract

Sclerotinia diseases and Phomopsis stem canker, among the most serious diseases threatening the success of sunflower (Helianthus annuus L.) production across the world, have been of increasing concern in recent history, and there is a need for additional inbred lines with resistance to these diseases. While breeding new lines capable of thriving in agricultural landscapes riddled with these widespread diseases, it is essential that lines also exhibit other desirable traits such as high yield potential, satisfactory fatty acid composition (e.g., high oleic acid), and herbicide tolerance (e.g., to imidazolinones), along with overall agronomic performance suitable to the northern Great Plains climate in the United States, and similar climates across other continents. A maintainer inbred germplasm line, HA 482 (Reg. no. GP-364, PI 690015), and two restorer inbred germplasms, RHA 483 (Reg. no. GP-365, PI 690016) and RHA 484 (Reg. no. GP-366, PI 690017), have been developed with the pedigree breeding method, evaluated through the use of testcross hybrid trials for both disease resistance and agronomic traits, and released by the USDA-ARS, Fargo, ND. All three lines have high oleic acid composition in the seed oil and exhibit resistance to Sclerotinia and Phomopsis stem canker, and both RHA 483 and RHA 484 are imidazolinone tolerant.

Unraveling the Sclerotinia Basal Stalk Rot Resistance Derived From Wild Helianthus argophyllus Using a High-Density Single Nucleotide Polymorphism Linkage Map

“…Breeding for BSR resistance traditionally followed the multiparent crosses of partially tolerant lines available in the primary gene pool followed by recurrent selection to achieve increased Sclerotinia resistance. Several sunflower germplasms and inbred lines with improved Sclerotinia resistance have been selected and released by the USDA-ARS for use in sunflower hybrid development ( Miller and Gulya, 1999 ; Miller et al, 2006 ; Talukder et al, 2017 ; Hulke et al, 2018 ; Money et al, 2019 ; Smart et al, 2019 ).…”

Genetic analysis of basal stalk rot resistance introgressed from wild Helianthus petiolaris into cultivated sunflower (Helianthus annuus L.) using an advanced backcross population

“…No complete resistance against Sclerotinia diseases has been identified in the sunflower gene pools. Increased Sclerotinia resistance has been achieved through routine mining of novel resistance sources in the sunflower primary gene pool and incorporated into breeding programs ( Miller and Gulya, 1999 ; Talukder et al., 2014a ; Seiler et al., 2017a ; Talukder et al., 2017 ; Hulke et al., 2018 ; Koehler et al., 2019 ; Money et al., 2019 ; Smart et al., 2019 ). Efforts have been made to study the nature and magnitude of BSR resistance alleles conferring quantitative genetic variations within sunflower germplasms using recombinant inbred line (RIL) populations, and a total of 20 quantitative trait loci (QTL) associated with BSR resistance were identified from two RIL populations developed from the crosses of HA441/RHA349 and PAC2/RHA266.…”