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Phenotypic Variation And Genetic Purity Of The Original 'Prime-Jim®' X 'Arapaho' Population, Loren M. Luther 2017 University of Arkansas

Phenotypic Variation And Genetic Purity Of The Original 'Prime-Jim®' X 'Arapaho' Population, Loren M. Luther

Horticulture Undergraduate Honors Theses

In 2013, Castro et al., produced the first linkage map for primocane-fruiting blackberries using the cross ‘Prime-Jim®’ x ‘Arapaho.’ This mapping population has been maintained since the original experiment with the hopes of conducting future studies. Further research was determined to be needed on the population to better characterize additional phenotypic traits, and since nine years had passed since the seedlings were established, there was a need to assess the continued genetic purity of the population using molecular methods. Phenotypic data was collected to analyze the variation of the population including soluble solids content, titratable acidity, average weight, shape, and ...


Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi 2017 University of Arkansas, Fayetteville

Temporal Evaluation Of Corn Respiration Rates Using Pressure Sensors, Gagandeep Singh Ubhi

Theses and Dissertations

High respiration rate of a grain indicates faster degradation of its dry matter. Proper grain management requires chronological and precise measurements of carbon dioxide evolved from grain respiration during the postharvest storage duration. Therefore the main goal of this research was to develop a new technique that evaluates temporal corn respiration rate using pressure sensors. It was based on measuring pressure drop associated with the grain respiration in a closed container and using it to calculate the grain respiration rates.

Dry corn (Zea Mays L.) was procured from a local farmer and stored at 4ºC. Corn rewetting technique was applied ...


Inheritance Studies Of Aromatic Compounds In Agastache Foeniculum (Pursh) Kuntze, Roger G. Fuentes-Granados, Mark P. Widrlechner, Lester A. Wilson 2017 Iowa State University

Inheritance Studies Of Aromatic Compounds In Agastache Foeniculum (Pursh) Kuntze, Roger G. Fuentes-Granados, Mark P. Widrlechner, Lester A. Wilson

Mark P. Widrlechner

Genetic control of volatile oil production in Agastache foeniculum and, more specifically, of the production of myrcene, limonene, and methyl chavicol, three major components of its essential oils, was elucidated. Controlled crosses were made between individuals with different chemotypes, and F2 populations were analyzed for their composition of volatiles by using headspace gas chromatography. Total aromatic volatile emittance was found to be under polygenic control with additive gene effects for four of eight families studied, and each of the three major components was controlled by one to a few genes with recessive to additive effects. Evidence is also presented suggesting ...


Results Of An Exploration To Expand The Diversity Of Daucus And Apiaceae Germplasm Collections, Mark P. Widrlechner, Kathleen R. Reitsma, David M. Brenner 2017 United States Department of Agriculture

Results Of An Exploration To Expand The Diversity Of Daucus And Apiaceae Germplasm Collections, Mark P. Widrlechner, Kathleen R. Reitsma, David M. Brenner

Mark P. Widrlechner

In volume 8 of this newsletter, Reitsma and Widrlechner {1998) reported on the status of Daucus and Apiaceae germplasm at the USDA-ARS North Central Regional Plant Introduction Station {NCRPIS), in Ames, Iowa. The NCRPIS is one of the primary active sites in the U.S. National Plant Germplasm System {NPGS), cons¢rving diverse collections of crop plants and their wild and weedy relatives and making them available for research and educational purposes at no cost to the user. Information about all NPGS collections can be obtained through the Germplasm Resources Information Network (GRIN) database, which can be searched via the ...


Pollination Methods For Maintaining Carrot Germplasm Collections, R. L. Wilson, M. P. Widrlechner, K. R. Reitsma 2017 United States Department of Agriculture

Pollination Methods For Maintaining Carrot Germplasm Collections, R. L. Wilson, M. P. Widrlechner, K. R. Reitsma

Mark P. Widrlechner

Field cage tests were run to determine if honey bees, Apis mellifera L., flies, Musca domestica L., or a combination of the two would provide the best pollination for carrot germplasm seed increase. In 1985, honey bees alone were significantly better pollinators than flies alone, but in 1988, a combination of honey bees and flies produced more carrot seed per cage than did honey bees or flies alone. Seed obtained by using the two pollinators did not differ significantly in 100 seed weight or germination percentage. Considerable time savings resulted from using insect pollinators rather than hand pollination. In the ...


Collecting Landscape Trees And Shrubs In Ukraine For The Evaluation Of Aesthetic Quality And Adaptation In The North Central United States, Mark P. Widrlechner, Robert E. Schutzki, Vasily Y. Yukhnovsky, Victor V. Sviatetsky 2017 United States Department of Agriculture

Collecting Landscape Trees And Shrubs In Ukraine For The Evaluation Of Aesthetic Quality And Adaptation In The North Central United States, Mark P. Widrlechner, Robert E. Schutzki, Vasily Y. Yukhnovsky, Victor V. Sviatetsky

Mark P. Widrlechner

Past experiences with long-term evaluations of woody landscape plants from Slovenia, Croatia, and Bosnia- Herzegovina in the north central United States indicated that a relatively low proportion of these introductions were well adapted to climatic and soil conditions. Based on these results, criteria were developed to focus future exploration for landscape trees and shrubs from more analogous environments in eastern and central Europe. Application of these criteria identified the forest– steppe transition zone in the northern half of Ukraine as a region with great potential, because of similarities to the north central United States in climatic extremes, soil types and ...


Daucus And Apiaceae In The Usda Germplasm Collection, Kathleen R. Reitsma, Mark P. Widrlechner 2017 Iowa State University

Daucus And Apiaceae In The Usda Germplasm Collection, Kathleen R. Reitsma, Mark P. Widrlechner

Mark P. Widrlechner

The North Central Regional Plant Introduction Station (NCRPIS) is one of the primary active sites in the U. S. National Plant Gennplasm System (NPGS). Nearly all of the NPGS's collections of Apiaceae, with the exception of Apium (celery), are conserved at the NCRPIS. The NCRPIS's Apiaceae germplasm is divided for management purposes into two groups, Daucus and Umbels, as shown in Table 1 and Table 2, respectively. The NCRPIS makes these germplasm samples available for research purposes at no cost to the user. Samples can be obtained by contacting the senior author at .


Inducing Germination Of Dormant Cuphea Seed And The Effects Of Various Induction Methods On Seedling Survival, W. W. Roath, M. P. Widrlechner 2017 Iowa State University

Inducing Germination Of Dormant Cuphea Seed And The Effects Of Various Induction Methods On Seedling Survival, W. W. Roath, M. P. Widrlechner

Mark P. Widrlechner

Cuphea wrightii Gray, and C. laminuligera Koehne are potential domestic sources of medium-chain-length fatty acids. These species have many undesirable characters including post harvest dormancy in which seeds remain dormant for one year or more. Researchers have shown that common techniques to induce germination in these species are not effective. Seed lots from these species were produced in 1983 and 1986. Excised seed (seed coats removed) and nonexcised seed (seed coats intact) were germinated on unsupplemented agar medium and on paper germination towels. No germination was obtained from nonexcised 1986 C. wrightii seed. Germination of I% or less was obtained ...


Evaluation Of Flowering Ash In Wichita, Kansas, John C. Pair, Mark P. Widrlechner 2017 Kansas State University

Evaluation Of Flowering Ash In Wichita, Kansas, John C. Pair, Mark P. Widrlechner

Mark P. Widrlechner

Flowering ash (Fraxinus omus L.) is native to southern Europe and western Asia. At maturity, this ash is an oval-headed tree with glossy, dark green leaves, which grows to about 50 feet (15 meters) tall. Its most notable feature appears in May: showy panicles of fragrant, cream-colored flowers, which help make this species a popular street and park tree in those regions where it is winter hardy. Dirr (1983) notes that it is hardy to -10°F (- 230C) and, similarly, it is listed for USDA Hardiness Zone 6 in Hortus Third (1976). A seedling population of flowering ash, PI 385252 ...


Amaranthus Seed Regeneration In Plastic Tents In Greenhouses, David M. Brenner, Mark P. Widrlechner 2017 Iowa State University

Amaranthus Seed Regeneration In Plastic Tents In Greenhouses, David M. Brenner, Mark P. Widrlechner

Mark P. Widrlechner

Amaranthus germplasm is efficiently regenerated in plastic tents within greenhouses . This protocol involves the cultivation of 100-plant populations in 0.8 m2 x 1 m tall tents , and generally yields 40 000-120 000 seeds about 3 months after planting. Expsriments were performed to test the effectiveness of pollination control by isolating four monoecious Amaranthus species in these plastic tents . The estimated f requency of pollen contamination between tents was 0.01%. The estimated frequency of cross-pollination within tents was 3.9%.


More Scn-Resistant Soybean Varieties Than Ever, But Diversity Of Resistance Is Lacking, Greg Tylka 2017 Iowa State University

More Scn-Resistant Soybean Varieties Than Ever, But Diversity Of Resistance Is Lacking, Greg Tylka

Gregory Tylka

Nearly 40 years after its discovery in the upper Midwest, the soybean cyst nematode (SCN) continues to be a highly damaging pathogen of soybeans in Iowa and surrounding soybean-producing states. SCN is most damaging in hot, dry growing seasons, but yield losses of 10% to 25% or more can occur in years when temperatures are moderate and rainfall is average or above average. Growing SCN-resistant soybean varieties can slow the build-up of SCN population densities (numbers) in the soil and produce profitable soybean yields in SCN-infested fields.


What’S The Situation With Scn In Your Fields?, Greg Tylka 2017 Iowa State University

What’S The Situation With Scn In Your Fields?, Greg Tylka

Gregory Tylka

The soybean cyst nematode (SCN) is capable of causing serious yield loss on soybeans every year and is widespread throughout Iowa and much of the Midwest. In the “good ole days,” a farmer was “good to go” with SCN management if he or she knew what fields were infested with the nematode and then grew SCN-resistant soybean varieties in rotation with the nonhost crop corn. Nowadays, though, things are a little more complicated. The fact is, your SCN numbers may be building up unbeknownst to you. This buildup can go unrecognized because a soybean crop often does not appear stressed ...


Performance Of Scn-Resistant Soybean Varieties In Iowa In 2016, Greg Tylka 2017 Iowa State University

Performance Of Scn-Resistant Soybean Varieties In Iowa In 2016, Greg Tylka

Gregory Tylka

Soybean varieties that are resistant to the soybean cyst nematode (SCN) are essential tools for managing the pest. Resistance to SCN requires multiple genes, and soybean varieties bred to be resistant may not contain all of the resistance genes necessary to provide maximum nematode control. Consequently, SCN control can vary greatly among resistant soybean varieties, just as yield. Iowa State University evaluates the SCN control and yield of SCN-resistant soybean varieties in field experiments conducted throughout Iowa annually. The effort is supported, in part, by soybean checkoff funds from the Iowa Soybean Association.


Last County In Iowa Found Infested With Scn, Greg Tylka, Brian Lang 2017 Iowa State University

Last County In Iowa Found Infested With Scn, Greg Tylka, Brian Lang

Gregory Tylka

More than 100 fields throughout Iowa were surveyed for the presence of the soybean cyst nematode (SCN) in 2016 in a project sponsored by the ISU Soybean Research Center and the Iowa Soybean Association (ISA). Soil samples were collected by Iowa State University Extension and Outreach field agronomists and ISA staff and interns and sent to the ISU Plant and Insect Diagnostic Clinic for processing.


The Genus Agastache As Bee Forage: An Analysis Of Reader Returns, George S. Ayers, Mark P. Widrlechner 2017 Michigan State University

The Genus Agastache As Bee Forage: An Analysis Of Reader Returns, George S. Ayers, Mark P. Widrlechner

Mark P. Widrlechner

In the May column, we reviewed published reports on the genus Agastache3 as bee forage and came to two somewhat contradictory conclusions:

1. The data support the contention that under proper circumstances several species of Agastache can be exceptional bee forage. These data came from observations made on both wild (Pellett, 1926; Vansell, 1933; and Wilson et al., 1958) and cultivated plants (Terry, 1872; Pellett, 1943 and 1946; and Mayer et al., 1982).

2. Despite Agastache's potential productivity and the fact that there were two historical periods in which one or more members of the genus were cultilvated for ...


Variation In The Breeding System Of Lycopersicon Pimpinellifolium: Implications For Germplasm Maintenance, M. P. Widrlechner 2017 United States Department of Agriculture

Variation In The Breeding System Of Lycopersicon Pimpinellifolium: Implications For Germplasm Maintenance, M. P. Widrlechner

Mark P. Widrlechner

From Regional (.NCRPIS) United (USDA) l.948 to 1986, the North Central Plant Introduction Station in Ames, Iowa maintained the states Department of Agriculture germplasm collections of Lycopersicon. Seed increases of Lycopersicon esculentum Miller and &· pimpinellifolium (Jusl.) Miller had been collected from field-grown plants with no controlled pollination and only limited effort to cull off-types, when they could be identified. Such methods have been successful in producing high-quality seed of many self-pollinating &· esculentum accessions, but the integrity of &· pimpinellifolium seed increases was questioned after the publication of research reports on the breeding biology of this species (Rick et al, 1977 ...


The Genus Agastache As Bee Forage: A Historical Perspective, George S. Ayres, Mark P. Widrlechner 2017 Michigan State University

The Genus Agastache As Bee Forage: A Historical Perspective, George S. Ayres, Mark P. Widrlechner

Mark P. Widrlechner

The September 1992 and January 1993 "The Other Side of Beekeeping" requested reader input about experiences with anise hyssop. This series of articles is our response to your replies. Most who made plantings were disappointed, yet historically, very competent apiculturists thought very highly of anise hyssop. In addition, our experiences with this plant and several closely related species make us ponder why the responses were not more positive. In this article, we review the history and biology of the genus Agastache as a bee forage. In the second article of the series, we will use this information to speculate on ...


Stratification And Light Improve Germination Of Katsura Tree Seed, Michael S. Dosmann, Jeffery K. Iles, Mark P. Widrlechner 2017 Iowa State University

Stratification And Light Improve Germination Of Katsura Tree Seed, Michael S. Dosmann, Jeffery K. Iles, Mark P. Widrlechner

Mark P. Widrlechner

Germinability of two, half-sib seed sources of Cercidiphyllum japonicum Sieb. & Zucc. and one seed source of Cercidiphyllum magnificum (Nakai) Nakai was determined after not stratifying or stratifying seeds at 3.5 ± 0.5 °C (38.3 ± 0.9 °F) for 8 days followed by germination for 21 days at 25 °C (77 °F) in darkness or under a 15-hour photoperiod. Stratification was not required for germination, but increased germination percentage, peak value, and germination value for both species. Stratification increased germination of C. japonicum from 42% to 75%, and germination of C. magnificum from 12% to 24%. Light enhanced germination ...


Relationships Between Nectar Production And Honey Bee Preference, Mark P. Widrlechner, Neil P. Senechal 2017 United States Department of Agricuture

Relationships Between Nectar Production And Honey Bee Preference, Mark P. Widrlechner, Neil P. Senechal

Mark P. Widrlechner

A 1989 review of research related to the improvement of nectar production in plants by Shuel presents evidence in support of intentional selection of plant genotypes for better nectar production. Such superior genotypes could be of great benefit for both beekeepers and other agricultural producers.


Short Term Pollen Storage Of Two Rhododendron Simsii Cultivars, Mark P. Widrlechner 2017 United States Department of Agriculture

Short Term Pollen Storage Of Two Rhododendron Simsii Cultivars, Mark P. Widrlechner

Mark P. Widrlechner

Rhododendron breeders work with a genus that collectively has a broad flowering season. However, many individual species or cultivars flower for much shorter periods. To make many desirable crosses, it becomes necessary for the breeder to store pollen. Existing literature offers only brief recommendations on storage conditions in reports by Bowers (1932), Lee (1958), and Schroeder and Bump (1982) and a single, more detailed report by Visser (1955) that few breeders have available.

This study outlines the relative value of a range of storage conditions for short-term (two weeks or less) pollen storage of two cultivars of evergreen azaleas. Long-term ...


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