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M.J. Striem, G. Ben-Hayyim, and P. Spiegel-Roy

Excluding seeded offspring at an early stage could be of great value to the breeder concerned with the development of seedless grapes (Vitis vinifera L.). We used the random amplified polymorphic DNA (RAPD) technique to identify molecular genetic markers, analyzing 82 individuals of a progeny resulting from a cross between `Early Muscat' (seeded) and `Flame Seedless'. Seven variables representing the traits of seedlessness were analyzed: mean fresh weight of one seed, total fresh weight of seeds per berry, perception of seed content, seed size categories evaluated visually, degree of hardness of the seed coat, degree of development of the endosperm, and degree of development of the embryo. Among 160 10mer primers, 110 gave distinct band patterns. Twelve markers yielded significant correlations with several subtraits of seedlessness, mainly with the mean fresh weight of one seed and the total fresh weight of seeds per berry. Multiple linear regression analysis resulted in high coefficients, such as R = 0.779 for fresh weight of seeds per berry, when the seven markers were included as independent variables in the model. Most of the seeded individuals, about 44% of the progeny, could be excluded using a two-step process of marker assisted selection.

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Jordan L. Hartman, Penelope Perkins-Veazie, and Todd C. Wehner

quality traits in the genotypes chosen for the 2017 study. In addition, the NCHYW was intercrossed more times than the NCSFW population, although the selection intensity was the same for both populations. This may account for the higher degree of

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Jareerat Chunthawodtiporn, Theresa Hill, Kevin Stoffel, and Allen Van Deynze

al., 1992 ; Walker and Bosland, 1999 ), whereas subsequent studies have implicated a role for multiple-gene QTL ( Kim et al., 2008 ; Lefebvre and Palloix, 1996 ; Minamiyama et al., 2007 ; Ogundiwin et al., 2005 ; Quirin et al., 2005 ; Rehrig et

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Heather L. Merk, Shawn C. Yarnes, Allen Van Deynze, Nankui Tong, Naama Menda, Lukas A. Mueller, Martha A. Mutschler, Steven A. Loewen, James R. Myers, and David M. Francis

trait data across multiple environments and generations in a high-throughput manner. Plant breeders are beginning to consider estimated breeding value, the merit of an individual as determined by the performance of its progeny rather than actual cultivar

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Christopher S. Cramer*

Heritability estimates of bolting percentage (BP), pink root (PR) and Fusarium basal rot (FBR) incidences, and percentage of single centered (PSC) bulbs were calculated for an intermediate-day, open-pollinated onion population using selection response and half-sib (HS) family analyses. BP was determined by counting the number of seedstalks per plot when the population was seeded at an earlier planting date to induce bolting. PR and FBR incidences were determined by rating 30 bulbs/plot for the severity of PR and FBR, and calculated an incidence rate from the number of infected bulbs out of 30 rated. The PSC bulbs was determined by cutting transversely 30 bulbs at the vertical center of the bulb and looking for the presence of a single growing point or multiple growing points within 1.3 cm from the center of the bulb. Families were also evaluated for bulb quality that consisted of shape, size, maturity, firmness, number of scale layers, and dry outer scale thickness, adherence, retention, and color. Families were selected based upon an index that equally weighted BP, PR and FBR incidences, PSC bulbs, and bulb quality. No progress was made for BP even though the narrow sense heritability (h2) estimate was 0.51. PR and FBR incidence was reduced by 18% and 12%, respectively, and realized heritability (RH) estimates of 0.65 and 0.60, respectively, were calculated. h2 estimates calculated through HS family analysis was 0.46 and 0.37, respectively, for these two traits. Very little progress was made for the PSC bulbs and this was reflected in a RH estimate of 0.17. However, the h2 estimate was 0.71, suggesting that progress should be possible.

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Tom DeGomez and Michael R. Wagner

Robinia L. (locust) species are among the most widely planted tree species in the world because they are ornamentally attractive, drought tolerant, fast growing, fix nitrogen, have very hard durable wood, and are adaptable to many sites and climates. Recent taxonomic analysis indicates there are four species, black locust (R. pseudoacacia L.); bristly locust (R. hispida L.); clammy locust (R. viscosa Vent.); and new mexican locust (R. neomexicana A. Gray). All four species originate in the southern United States and northern Mexico. Many horticultural cultivars are available. Locusts are tolerant of a wide range of soil types so long as there is good drainage, adequate moisture, and it is not very clayey. The environmental tolerance of locust makes it an excellent candidate for horticultural uses and for future breeding and selection to enhance its many desirable traits. It is easy to propagate via seed, root cuttings, soft- or hardwood cuttings, budding/grafting, or tissue culture. Locust has indeterminate growth. Spacing of plants in plantations is critical for the production of multiple products including high value timber. Locust is known for its ability to withstand drought conditions however at the cost of leaf shedding. Black locust contributes high levels of nitrogen to the soil from nitrogen fixing bacterial symbiosis. The major drawback to large-scale production of black locust in its native range is the damage that occurs from the locust borer (Megacyllene robiniae Forster). When planted outside the range of the locust borer it can be grown successfully as landscape specimen trees and as trees large enough for lumber production when varieties with straight trunks are grown. Damage from locust leaf miner (Odontata dorsalis Thunberg) can greatly detract from the trees ornamental qualities. Its most common use is as a site reclamation species. The tree is also used in honey production. The wood is highly decay resistant and is greatly valued for poles and posts. The wood is extremely hard and easy to work making it highly desirable for many construction uses.

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Zhuping Fan, Yike Gao, Ling Guo, Ying Cao, Rong Liu, and Qixiang Zhang

cultivars with specific traits ( Azimi et al., 2018 ). Characteristics with high heritability can be useful for hybrid selection in iris breeding ( Azimi et al., 2018 ). Over the past decades, researchers have carried out several studies about the trait

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Vance M. Whitaker, Tomas Hasing, Craig K. Chandler, Anne Plotto, and Elizabeth Baldwin

selections will continue to be performed to more firmly establish the optimal range for SSC/TA. Significant genotype × environment and genotype × month interactions for most fruit chemical traits demonstrate that advanced selections must be tested in multiple

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Chengyan Yue, R. Karina Gallardo, James Luby, Alicia Rihn, James R. McFerson, Vicki McCracken, Vance M. Whitaker, Chad E. Finn, James F. Hancock, Cholani Weebadde, Audrey Sebolt, and Amy Iezzoni

and processing markets. Overall, these studies give some insights to breeders’ preferences; however, a systematic investigation of producers’ value of strawberry traits would assist in breeders’ selection of traits and improve the efficiency of

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R. Karina Gallardo, Qi Zhang, Michael Dossett, James J. Polashock, Cesar Rodriguez-Saona, Nicholi Vorsa, Patrick P. Edger, Hamid Ashrafi, Ebrahiem Babiker, Chad E. Finn, and Massimo Iorizzo

a systematic investigation of the blueberry industry’s trait priorities has not been conducted. Such information would assist in breeders’ selection of traits and improve the efficiency of breeding programs. The goal of this study was to survey and