Registration of N619 to N640 Grain Sorghum Lines with Waxy or Wild-Type Endosperm

Abstract

Sorghum [Sorghum bicolor (L.) Moench] lines N619 to N636 (A lines; Reg. No. GS‐699 to GS‐716, PI 670134 to PI 670151); N619 to N636 (B lines; Reg. No. GS‐721 to GS‐738, PI 671777 to PI 671794); and N637 to N640 (R lines; Reg. No. GS‐717 to GS‐720, PI 670152 to PI 670155) comprise nine pairs of seed parent (A/B) lines, and two pairs of pollinator (R) lines (11 pairs total) that are near‐isogenic for waxy (low‐amylose) or wild‐type endosperm. Breeding work was conducted jointly by the USDA–ARS and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska, and the lines were released in May 2014. Release of these lines makes available two different waxy (wx) alleles (wxa and wxb) for development of grain sorghum as a source of low‐amylose starch, whose end use is targeted to the ethanol and food industries. In particular, the release of wx and wild‐type near‐isogenic pairs facilitates the evaluation of agronomic performance of wx genotypes, and the release of both A/B and R lines facilitates the production of waxy grain hybrids.

Evaluation of Interallelic waxy, Heterowaxy, and Wild‐Type Grain Sorghum Hybrids

“…Jampala et al (2012) concluded that genetic linkage resulting in reduced yields of wx sorghum may be unique to the population and parents tested (e.g., background effects). Observed differences in grain yield and height among near‐isogenic WT and wx lines by Yerka et al (2015a,b), and hybrids in the current study, support this conclusion.…”

“…The cause of generally lower yield in previous evaluations of the wx b inbred lines evaluated in Yerka et al (2015a) is not known; however, grain yield was highest for hybrids with the wx b Wheatland parent in the current study. The above observations suggest that the Wx locus may be linked to alleles affecting height and yield; however, the lack of a consistent positive or negative association between wx alleles, height, and yield in Yerka et al (2015a) suggests that the three traits are not tightly linked. Further research will be needed to definitively test additive, dominance, and epistasis variance in a broader set of wx hybrids with different combinations of wx a and wx b alleles to identify favorable haplotypes.…”

“…Improving agronomic performance of wx lines and hybrids relative to WT has been difficult to achieve consistently (Jampala et al, 2012; Rooney et al, 2005; Yerka et al, 2015a). In particular, Yerka et al (2015a) evaluated 11 pairs of grain sorghum lines near‐isogenic for wx or WT: two wx lines (BN619 and BN635) differed in floral synchrony from their respective WT lines, and five wx lines (BN619, BN621, BN635, RN637, and RN639) differed in height. However, wx genotypes were not consistently associated with increased time to anthesis or increased height at maturity.…”

“…The ethanol fermentation efficiency benefits of waxy sorghum grain are well documented (Sharma et al, 2007; Wang et al, 2008; Yan et al, 2011; Wu et al, 2013). Despite the utility of waxy sorghum grain in the ethanol and food industries, the waxy trait has historically been associated with yield drag (Rooney et al, 2005), because of uncharacterized factors (Jampala et al, 2012; Yerka et al, 2015a), or its presence in unadapted genetic backgrounds. Further development and characterization of high‐yielding waxy parent lines and hybrids should contribute to the commercialization of waxy sorghum for end uses in the ethanol and food industries.…”

Near isogenic lines (NIL) of sorghum carrying wild type or waxy alleles of the granule-bound starch synthase (GBSS) gene have distinct effects on human gut microbiome phenotypes and host physiological characteristics

“…Since discovery of the waxy phenotype in maize, naturally occurring waxy variants have also been identi ed in many other grain crops, including sorghum, rice, proso millet, and wheat. In the cases that have been studied, causal variants of the waxy phenotypes in cereal grains are due to loss of function mutations in the gene encoding granule-bound starch synthase (GBSS), the enzyme responsible for amylose synthesis in starch granules [8][9][10][11][12][13][14]. Like the original waxy maize variant, starch from waxy variants of these other cereal grains contains high percentages of amylopectin and little or no amylose due to the GBSS mutation [5,[8][9][10][11][12][13].…”