'ND Twilight' black bean (RFP-321)


ND Twilight black bean is the result of the cross ND021717/VAX-5. NDSU breeding line ND021717 is a black-seeded genotype with excellent upright plant architecture, early maturity and high seed yield obtained from the cross VAX-4/Raven//T-39. Germplasm lines VAX-4 and-5 are highly resistant to CBB and are the product of interspecific crosses with tepary bean (Phaseolus acutifolus Asa. Gray). Raven and T-39 are well-known black bean cultivars with high seed yield and quality. In fact, T-39 (a selection of Black Turtle Soup or BTS) is the cultivar that started production of black beans in the U.S. back in the 1960s and 1970s. The goal of this cross was to combine the excellent agronomic attributes of breeding line ND021717 with increased levels of CBB resistance.

Routine greenhouse screening of ND Twilight in 2016 with race 20-3 of U. appendiculatus showed that the line is resistant. The presence of the diagnostic marker for the Ur-11 resistance gene was confirmed in the line. Leaf symptoms were similar to the typical reaction of the original source of the Ur-11 gene (PI 191899), which is known to confer resistance to race 20-3. However, inconsistent virulence to 20-3 was identified in additional evaluations made in 2018. Therefore, an additional test was made in December 2019 using race 20-3, which included all the parental lines of ND Twilight. In this screening, all plants of ND Twilight, Raven and T-39 were resistant (no symptoms), suggesting that the resistance may be coming from Raven and/or T-39 while VAX-4 and VAX-5 exhibited pustules characteristic of infection by U. appendiculatus. The susceptible control (Othello pinto bean) showed high levels of rust infection as expected. While the preponderance of evidence supports that ND Twilight is resistant, we will test additional pathogen isolates (races 20-3) from different collection points in North Dakota during the winter to ensure broad resistance.

The NDSU Research Foundation has applied for protection for ND Twilight under the Plant Variety Protection Act (PVPA) with Title V (Application No. 202000258) and collects research fees on this variety. In order to ensure genetic purity, ND Twilight under PVPA Title V must be sold as a class of certified seed.

Additional data in brochure:

  • Table 1: North Dakota data for seed yield
  • Table 2: North Dakota date for seed weight, maturity, plant height, canning score, rust scores, and CBB 


ND Twilight Fact Sheet 1.pdf

ND Twilight Fact Sheet 2.pdf 

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