Registration of Oilseed Sunflower Germplasm HA‐BSR1 Highly Tolerant to Sclerotinia Basal Stalk Rot

Abstract

Basal stalk rot (BSR) is a devastating disease that causes a significant damage to sunflower (Helianthus annuus L.) production worldwide by reducing seed yield and quality. The objective of this research was to develop highly BSR tolerant sunflower germplasm by incorporating genetic factors from various partially tolerant breeding lines. HA‐BSR1 (Reg. No. GP‐336, PI 678571) sunflower germplasm is an F7–derived oilseed maintainer developed from the cross HA 441/RHA 439, selected for tolerance to Sclerotinia BSR. HA‐BSR1 showed significantly higher tolerance to BSR disease than both of the parents and the checks when evaluated across seven environments in North Dakota and Minnesota from 2012 to 2015. A 4‐yr mean disease incidence of HA‐BSR1 was 1.6% compared with the parents HA 441 (20.0%) and RHA 439 (12.6%), the susceptible hybrid check ‘Cargill 270’ (32.8%), and the resistant hybrid check ‘Croplan 305’ (10.4%). Molecular genetic analysis of HA‐BSR1 indicated the presence of six alleles associated with quantitative trait loci (QTL) conferring resistance against BSR, three alleles derived from each parents. The release of HA‐BSR1 along with the information of single nucleotide polymorphism markers linked to QTL will be useful in marker‐assisted selection breeding to pyramid BSR resistance with other desirable agronomic traits in elite sunflower lines.

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 ).…”

Validated markers for sunflower (Helianthus annuusL.) breeding

“…Resistance to the disease has been found in related wild species but is known to be of polygenic inheritance and was absent in cultivated germplasm until recently (Micic et al, 2005a). However, breeding lines such as HA-BSR1 have been registered, which have high tolerance to Sclerotinia basal stalk mold originating from parents HA 441/RHA 439 (Talukder et al, 2017). Narrow sense heritability ranged between 2-60% for Sclerotinia resistance (Zubrzycki and Maringolo, 2017), indicating the possibility for good gain from selection, and the possibility of identifying genes of major effect on resistance.…”

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.…”