Registration of Oilseed Sunflower Germplasms RHA 461, RHA 462, RHA 463, HA 465, HA 466, HA 467, and RHA 468 with Diversity in Sclerotinia Resistance, Yield, and Other Traits

Abstract

Sclerotinia head and stalk rots are among the most devastating diseases in sunflower (Helianthus annuus L.). Breeding for resistance to these diseases while maintaining or improving yield and quality is complicated by the quantitative inheritance of the resistance, for which there are few genes of major effect. The objective of this work was to provide new diversity to sunflower breeding organizations for yield and Sclerotinia resistance, together with other useful agronomic and end user traits. Four restorer germplasms, RHA 461 (Reg. No. GP‐337, PI 655012), RHA 462 (Reg. No. GP‐338; PI 655013), RHA 463 (Reg. No. GP‐339; PI 655014), and RHA 468 (Reg. No. GP‐341; PI 667184), and three maintainer germplasms, HA 465 (Reg. No. GP‐342; PI 670488), HA 466 (Reg. No. GP‐340; PI 667183), and HA 467 (Reg. No. GP‐343; PI 670489) were developed by the USDA‐ARS and the North Dakota Agricultural Experiment Station, Fargo, ND. Testcrosses with these germplasms had yield similar to high‐yielding commercial checks and Sclerotinia resistance similar to the highly resistant check ‘Northrup King 277’. Some of the lines also have high oleic acid in the seed oil, downy mildew resistance, and tolerance to imidazolinone herbicides. The lines are available for sunflower breeders to integrate into their breeding programs for additional diversity.

Registration of Oilseed Sunflower Germplasms RHA 485, RHA 486, and HA 487, Selected for Resistance to Phomopsis Stalk Canker and Sclerotinia, in a High‐Yielding and High‐Oil Background

“…‘RHA 426’ (PI 617099) and ‘RHA 428’ are restorer inbred germplasms developed by the USDA‐ARS and the North Dakota Agricultural Experiment Station (NDAES) possessing imidazolinone herbicide tolerance and DM resistance conditioned by the Pl 34 gene, respectively (Miller and Al‐Khatib, 2002; Miller et al, 2002; Talukder et al, 2019). ‘RHA 463’ (PI 655014) is a restorer oilseed germplasm developed by the USDA‐ARS and the NDAES in 2006 (Hulke et al, 2018). ‘HA 466’ (PI 667183) is a Sclerotinia‐resistant, high‐oleic oilseed maintainer line released by the USDA and the NDAES in 2006 (Hulke et al, 2018).…”

“…‘RHA 463’ (PI 655014) is a restorer oilseed germplasm developed by the USDA‐ARS and the NDAES in 2006 (Hulke et al, 2018). ‘HA 466’ (PI 667183) is a Sclerotinia‐resistant, high‐oleic oilseed maintainer line released by the USDA and the NDAES in 2006 (Hulke et al, 2018). ‘Almanzor’ was a hybrid evaluated in the Food and Agriculture Organization (FAO) Hybrid Sunflower Yield Trial.…”

“…Sclerotinia HR resistance was assessed on testcross hybrids of the experimental line with the cytoplasmic male sterile (CMS) version of ‘HA 412HO’ (Miller et al, 2006; for restorer experimentals) or ‘RHA 468’ (Hulke et al, 2018; for maintainer experimentals). The screenings took place in 2011 and 2012 at fields with Bayer CropScience in Sabin, MN, and the Ag and Energy Center, Central Lakes College, Staples, MN, and from 2014 to 2016 at Staples and the North Dakota State University (NDSU) Research and Extension Center in Carrington, ND.…”

Registration of Oilseed Sunflower Restorer Germplasms RHA 476 and RHA 477, Adapted for Short Season Environments

“…RHA 418 (PI 607508) and RHA 419 (PI 619204) are oilseed restorer lines released by the USDA and NDAES in 1998 and 1999, respectively (Miller et al, 2002). RHA 468 (PI 667184) is an imidazolinone herbicide tolerant oilseed restorer line released by the USDA and NDAES in 2006 (Hulke et al, 2017). Both RHA 419 and RHA 468 carry the Pl ARG gene for downy mildew resistance.…”

“…RHA 477 is a downy mildew–resistant, imidazolinone herbicide–tolerant F 6 –derived F 9 restorer oilseed sunflower line selected from the cross RHA 468/R‐7009. Downy mildew resistance is conferred by the Pl ARG gene, which provides resistance to all known races of downy mildew (Hulke et al, 2017; Qi et al, 2017). For each F 8 plant that made up the breeder seed of RHA 477, a greenhouse test showed that 20 seedlings exhibited resistance to downy mildew, with zero susceptible, indicating that each head row was fixed for resistance with 99% confidence based on Sedcole's test.…”