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The majority of hazelnut plantings in the Upper Midwest of the United States are planted with seedlings from crosses between American hazelnuts (Corylus americana) and European hazelnuts (C. avellana) that were initially made in the 1930’s. To evaluate the potential of this material to support a commercial industry, we have populated replicated field trials at five locations with clonal material of high performing accessions selected from these plantings. The hybrid plants in these trials were found to have high levels of genetic diversity when assessed at 10 microsatellite loci. Principal component analysis shows these Midwestern hybrids group genetically with American hazelnuts from the Upper Midwest region, but separately from European hazelnuts and hybrid hazelnuts developed elsewhere. We conclude that this pool of hybrids has sufficient genetic diversity for a breeding program to support a regional hazelnut industry. The average yield of the eight highest yielding of these genotypes, at ages six to 8 years, was 180 g m−2 of canopy area at the most productive site, which in a production system with 50% of the land covered by the crop canopy would translate to 895 kg of kernel ha−1. This compares favorably with expected yields of similarly aged European tree hazelnuts in Oregon. Though smaller than nuts from European cultivars, kernel quality of the top eight selections was deemed to be adequate for the processed nut market.

Illinois bundleflower Desmanthus illinoensis (Mich.) MacMill is a warm-season perennial legume native to the central USA. Little is known about its forage quality in the upper midwestern USA. Two experiments were established at four Minnesota locations in 2000 to evaluate the effects of N fertilization, maturity at harvest, and residual height of cutting on the acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein (CP), in vitro true digestibility (IVTD), in vitro dry matter digestibility (IVDMD), and leaf proportion of three Illinois bundleflower (IBF) ecotypes. Whole-herbage forage quality was greatest (P < 0.05) at early flower in mid-July with average ADF, NDF, and CP concentrations of 315, 352, and 180 g kg(-1), respectively. Fiber values increased to 412 and 479 g kg(-1), respectively, while CP decreased to 129 g kg(-1) at late pod in mid-August. Leaf proportion decreased (P < 0.05) from 618 g kg(-1) at early flower to 335 g kg(-1) at late pod while leaf CP decreased (P < 0.05) from 216 to 147 g kg(-1). Whole-herbage IVDMD and IVTD concentrations decreased (P < 0.05) from 470 and 648 g kg(-1) at early flower to 390 and 560 g kg(-1) at late pod, respectively. Increasing residual cutting height from 15 to 35 cm decreased (P < 0.05) ADF and NDF concentrations by an average of 50 g kg(-1) and increased (P < 0.05) IVTD, IVDMD, and CP concentrations by 43, 39, and 20 g kg(-1), respectively. Illinois bundleflower can provide good quality summer forage in the upper midwestern USA, but more research is needed to ascertain the implications of its low IVDMD on animal performance.

Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMillan] is a warm‐season perennial legume native to the central plains of the USA with potential as both a forage and grain crop. The effects of management variables on Illinois bundleflower (IBF) forage production in the upper midwestern USA have not been evaluated. We evaluated the effects of maturity at harvest, cutting height, and N fertilization on forage yield, regrowth, and persistence of three northern ecotypes of IBF. Field experiments were established at four Minnesota locations in 2000. Total‐season forage yields in postestablishment years ranged from 2.5 to 5.3 Mg dry matter (DM) ha−1 across environments. First‐harvest forage yield increased (P < 0.05) from 2.8 Mg DM ha−1 at early flower in mid‐July to 4.2 Mg DM ha−1 at late pod in mid‐August. In mid‐September, within‐season regrowth averaged 1.7 Mg ha−1 from plants previously cut at early flower and 0.6 Mg ha−1 from plants cut at late pod. A 35‐cm cutting height resulted in 60% more regrowth yield (P < 0.05) than a 15‐cm cutting height, but only in plants harvested at early flower. Plants cut at late pod in 2001 did not persist into 2002. October root total nonstructural carbohydrate (TNC) concentration ranged (P < 0.05) from 244 g kg−1 in plants cut at late pod to 280 g kg−1 in plants left uncut. Complete winterkill of all treatments at all locations between 2002 and 2003, regardless of October TNC level, may have been caused by below‐average snow cover. Illinois bundleflower can provide summer forage in the upper midwestern USA, but persistence in monoculture is limited, especially in harsh winters.

In Minnesota, perennial native legumes (Fabaceae) differed in population and yield response to seeding rates of 14, 67, 135, 275, and 538 pure live seeds (PLS)/m² (1.3, 6.3, 12.5, 25, and 50 PLS/ft²) when seeded in cultivated seedbeds with little bluestem (Schizachryium scoparium (Michx.) Nash [Poaceae]). Average seeding-year populations were greatest for Illinois bundleflower (Desmanthus illinoensis (Michx.) MacM. ex B.L. Robins. & Fern.) (131 plants/m²); intermediate and similar for false indigo (Amorpha fruticosa L.), wild blue indigo (Baptisia australis (L.) R. Br), and wild senna (Senna hebecarpa (Fern.) H.S. Irwin & Barneby) (average of 72 plants/m² ); and least for purple prairie clover (Dalea purpurea Vent) (27 plants/m²). Seeding-year populations of all legumes increased linearly as seeding rate increased. Second-year biomass yield of legumes in mixture with little bluestem ranged from 1.1 Mg/ha (0.5 tons/ac) for purple prairie clover to 5.6 Mg/ha (2.5 tons/ac) for Illinois bundleflower.

Illinois bundleflower [Desmanthus illinoensis (Michx.) MacMillan] is a warm-season perennial legume native to the central plains of the USA with potential as both a forage and grain crop. The effects of management variables on Illinois bundleflower (IBF) forage production in the upper midwestern USA have not been evaluated. We evaluated the effects of maturity at harvest, cutting height, and N fertilization on forage yield, regrowth, and persistence of three northern ecotypes of IBF. Field experiments were established at four Minnesota locations in 2000. Total-season forage yields in postestablishment years ranged from 2.5 to 5.3 Mg dry matter (DM) ha⁻¹ across environments. First-harvest forage yield increased (P < 0.05) from 2.8 Mg DM ha⁻¹ at early flower in mid-July to 4.2 Mg DM ha⁻¹ at late pod in mid-August. In mid-September, within-season regrowth averaged 1.7 Mg ha⁻¹ from plants previously cut at early flower and 0.6 Mg ha⁻¹ from plants cut at late pod. A 35-cm cutting height resulted in 60% more regrowth yield (P < 0.05) than a 15-cm cutting height, but only in plants harvested at early flower. Plants cut at late pod in 2001 did not persist into 2002. October root total nonstructural carbohydrate (TNC) concentration ranged (P < 0.05) from 244 g kg⁻¹ in plants cut at late pod to 280 g kg⁻¹ in plants left uncut. Complete winterkill of all treatments at all locations between 2002 and 2003, regardless of October TNC level, may have been caused by below-average snow cover. Illinois bundleflower can provide summer forage in the upper midwestern USA, but persistence in monoculture is limited, especially in harsh winters.

This study reports a genetic map created using a progeny family descended from the interspecific hazelnut cross Corylus avellana x Corylus americana. This research represents a critical step in the development of genomic tools that enable the deployment of next-generation sequencing methods in the breeding of hazelnut, specifically the improvement of well-adapted Midwestern hazelnut varieties. To produce this map, we first developed high-density molecular markers using short-read Illumina sequencing of genotype-by-sequencing libraries. By aligning reads to a newly assembled reference genome for C. americana, we were able to identify over 75,000 high-quality indel-based polymorphisms across an F1 experimental population. These markers exhibited both high allele depth coverage, and low linkage disequilibrium, making them well-suited to genetic map development. We constructed such a map using 95 individuals from a single F1 family, demonstrating the utility of next-generation sequencing to efficiently and accurately generate high-density genetic maps. This research will improve the efficiency of breeding efforts, both through the validation of specific molecular markers that are associated with agronomically-relevant traits in breeding populations of interest.Competing Interest StatementThe authors have declared no competing interest.Footnotes* https://doi.org/10.6084/m9.figshare.21902193

Multipotent adipose-derived stem cells (ASCs) are increasingly used for regenerative purposes such as soft tissue reconstruction following mastectomy; however, the ability of tumors to commandeer ASC functions to advance tumor progression is not well understood. Through the integration of physical sciences and oncology approaches we investigated the capability of tumor-derived chemical and mechanical cues to enhance ASC-mediated contributions to tumor stroma formation. Our results indicate that soluble factors from breast cancer cells inhibit adipogenic differentiation while increasing proliferation, proangiogenic factor secretion, and myofibroblastic differentiation of ASCs. This altered ASC phenotype led to varied extracellular matrix (ECM) deposition and contraction thereby enhancing tissue stiffness, a characteristic feature of breast tumors. Increased stiffness, in turn, facilitated changes in ASC behavior similar to those observed with tumor-derived chemical cues. Orthotopic mouse studies further confirmed the pathological relevance of ASCs in tumor progression and stiffness in vivo. In summary, altered ASC behavior can promote tumorigenesis and, thus, their implementation for regenerative therapy should be carefully considered in patients previously treated for cancer.

World hazelnut production is based on European hazelnut (Corylus avellana) and is limited by the narrow climatic requirements of this species. The cold hardiness and disease resistance of the American hazelnut (Corylus americana) offer opportunities to expand production to new areas including the Upper Midwest (USA). The American hazelnut is a phenotypically diverse species. This study used ten microsatellite marker loci to investigate genetic diversity in 1140 individuals sampled from 25 populations across Wisconsin, Iowa, Minnesota and North Dakota. Overall, the marker loci were highly polymorphic (Ho = 0.69, He = 0.78, PIC = 0.84) with 7–13 alleles per locus. There was very high genetic diversity within populations (90% of the total) and some tendency toward population differentiation. Mantel’s test showed that genetic distance among the populations was not correlated with geographic distance. We conclude that selection of individuals for use in breeding should be based primarily on phenotype (productivity, nut size, percent kernel, ease of harvest), with care to include representatives of genetically differentiated populations.

We have been selecting high yielding American hazelnut ( Corylus americana ) from wild populations. Because hazelnuts tend to have a spreading growth form, it was unclear whether phenotypic variation among the individual stems of a clump was due to multiple genotypes which had grown together. This would significantly complicate selection. In order to determine if these bushes were single genotypes, we collected leaf samples from the four cardinal directions from each of 23 high producing stems. These were analyzed for 4–6 microsatellite loci. We determined that of the 23 selections, 5 were composed of more than one genotype. Additionally, one clump had one allele on one direction that was different (likely allele dropout from a heterozygote where one allele did not amplify correctly). Overall, the majority of clumps (78 %) were composed of a single genotype. This suggests that selecting at the level of “clump” is viable. Additionally, we noticed that within our selection sites, certain plants seemed to function only as males (produced male catkins but seldom produced female flowers) while others produced copious female flowers and subsequently nuts. Within one site, we selected 20 hazelnuts with both male and female flowers and 19 with only male flowers. Using the same microsatellite techniques for 10 loci, we assessed whether there were obvious genetic differences between these types of plants. Overall, there was no difference between plants that bore female flowers and those that did not. Microsatellite DNA techniques are becoming a more useful tool for selection of potential agroforestry crops from wild populations.