Blaine Schatz

Genome-Wide Mapping of Spike-Related and Agronomic Traits in a Common Wheat Population Derived from a Supernumerary Spikelet Parent and an Elite Parent

In wheat, exotic genotypes harbor a broad range of spike‐related traits, and can be used as a source of new genes for germplasm enhancement in wheat breeding programs. In the present study, a population of 163 recombinant inbred lines was derived from a cross between an elite line (WCB414) and an exotic line (WCB617) with branched spike (supernumerary spikelet; SS) head morphology. The population was evaluated over four to six environments to identify quantitative trait loci (QTL) associated with nine spike‐related traits and 10 agronomic traits. A genetic map consisting of 939 diversity arrays technology (DArT) markers was constructed. Composite interval mapping identified a total of 143 QTL located on 17 different wheat chromosomes and included 33 consistent and definitive QTL. The amount of phenotype variation explained (PVE) by individual QTL ranged from 0.61 to 91.8%. One major QTL for glume pubescence was located in a QTL‐rich region on the short arm of chromosome 1A, where loci for other traits such as for kernels per spike (KS) and spike length (SL) were also identified. Similarly, a cluster of QTL associated with yield‐related, agronomic and spike‐related traits contributing up to 40.3% of PVE was found on the short arm of chromosome 2D, in the vicinity of a major QTL for SS‐related traits. Consistent and major QTL identified in the present study may be useful in marker‐assisted breeding programs to facilitate transfer of desirable alleles into other germplasm. Desirable QTL alleles were also contributed by the exotic line, suggesting the possibility of enriching the breeding germplasm with alleles from SS genotypes.

Quality Trait Variation in Major Hard Red Spring Wheat Cultivars Released in North Dakota Since 1968

ABSTRACT Over the last 40 years, grain yield of hard red spring wheat (HRSW) (Triticum aestivum L.) has increased dramatically in North Dakota and neighboring regions. This yield increase has caused some concern that recent higher yielding cultivars might be released at the expense of quality performance. A two-year study was initiated in 2004 to examine the changes in quality performance of HRSW cultivars released by North Dakota State University (NDSU) over the past 40 years. The experiment was conducted in North Dakota at three and two sites in 2004 and 2005, respectively. The study included 33 HRSW genotypes laid out in a randomized complete-block design with four replicates. Grain protein content, flour-extraction yield, mixogram scores, Falling Number, glutograph scores, water absorption, dough character score, and loaf volumes did not vary significantly with year of release. Linear regression of cultivar means on year of release showed an annual increase in crumb color score of 0.4%/yr since 1968. ...

Use of shoot reduction treatments as a means of simulating hail injury to proso millet

Abstract Proso millet, Panicum miliaceum (L.), is a warm‐season annual grass well adapted for grain production in the western Great Plains of the United States, where risk of hail injury is greater than any other region of the United States. Because adjustment procedures and loss equations are not available, proso millet producers in this region have had limited access to crop hail insurance as a risk management tool. Our research was conducted to assess impact of shoot reduction treatments imposed at different crop growth stages on grain yield loss of proso millet grown under several environments. Our goal was to provide information for development of crop insurance adjustment procedures. We also wanted to determine the impact of shoot reduction on various grain yield components. Treatments consisted of a control and three levels of shoot reduction (33,66, and 100% of full stand) applied at four growth stages (emergence, 4‐leaf, boot, and heading stages). The experiments were conducted at two locations (Akron, CO and Carrington, ND) during 1996 and 1997 to assess treatment impact on relative grain yield (RGY), expressed as percent of control. A significant shoot reduction χ growth stage interaction was observed for RGY, indicating yield loss from increasing shoot reduction varied with growth stage. A linear reduction in RGY to increasing levels of shoot reduction was observed for the 4‐leaf, boot and heading growth stages, while RGY displayed a segmented linear response to increasing shoot reduction at emergence. Variation in grain yield, induced by shoot reduction treatments, was more consistently correlated with variation in seed number than seed weight.