T.G. Beckman

United States Department of Agriculture

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Publications (84)

  • C. Chen · W.R. Okie · T.G. Beckman
    [Show abstract] [Hide abstract] ABSTRACT: Peach fruit set is affected by cumulative chill and spring frost. A spring frost occurred on 29 Mar. 2015 at the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS) Byron station after 3 weeks of bloom, reducing fruit set and resulting in many buttons (abnormally small fruit with dead embryos). Fruit set was rated in 2014, 2015, and 2016 and button set rated in 2015 using the same scale (0 = no fruit/button to 9 = 1-2 fruit/button at every node). The overall fruit set rating was substantially different in the 3 years, averaging 5.61 in 2014, 2.61 in 2015, and 6.04 in 2016. Buttons and skin-damaged fruit in 2015 varied among peach genotypes. Comparison of fruit and button set ratings showed that there was no difference between cultivars and selections, but some significant differences in fruit set for four ripening months, among the 3 years, and among the nine chilling classes, respectively. Among the cultivars, the most common button set rating was 0-3. For example, ‘Sunprince’, ‘Loring’, and ‘Carored’ trees had a high button set rating, whereas ‘Flameprince’, ‘Julyprince’, and ‘Contender’ trees were low. As for peach selections, BY04P1690n was among those with the highest button set rating. In the population derived from a cross of button-prone BY04P1690n and button-free BY99P3866w, fruit and button counts from 10 long fruiting shoots ranged from 4 to 53 fruit (21.63 on average) and 2 to 27 buttons (10.39 on average). The peach button rate ranged from 5.36% to 87.10% (30.70% on average). The range, distribution, and percentage of the button counts suggested that, if buttoning was genetically controlled, it appeared quantitative. Further assessment is needed. © 2016 American Society for Horticultural Science. All rights reserved.
    Article · Jul 2016
  • T.G. Beckman · J.X. Chaparro
    [Show abstract] [Hide abstract] ABSTRACT: The primary focus of the stone fruit rootstock program at Byron, Georgia has been the development of disease resistant rootstocks for peach. Historically peach tree short life (PTSL), aka 'Bacterial Canker Complex', and Armillaria root rot (ARR) have been the two most important causes of premature mortality of commercial peach trees in the southeastern United States. However, following the cooperative release of Guardian rootstock by the USDA-Agricultural Research Service and Clemson University in 1993 the southeastern peach industry has enjoyed a marked decline in incidence of PTSL. Unfortunately, Guardian, like most other peach seedling rootstocks, is very susceptible to ARR. As a result, ARR has now moved to the forefront as the primary cause of premature peach tree death in the Southeast. Since its inception in 1988, the Byron rootstock program has focused on the breeding and development of new peach, plum and plum × peach interspecific hybrid rootstocks with resistance to PTSL, ARR and several species of root-knot nematode including Meloidogyne incognita, M. javanica and M. floridensis. M. floridensis is a recently identified nematode species with demonstrated ability to attack many of the current commercial peach rootstocks with resistance to M. incognita, including Okinawa, Nemared, Nemaguard and Guardian. Our breeding and evaluation work has recently culminated in the release of two clonal rootstocks with broad disease and nematode resistance. 'Sharpe', a semidwarf, clonal, plum hybrid, was released in 2007 for commercial testing and as a germplasm line. 'MP-29', a semi-dwarf, clonal, plum × peach hybrid, was released in 2011 for commercial testing. 'MP-29's broad disease and nematode resistance in combination with its dwarfing ability and excellent productivity offers great promise for use in this production area and others worldwide suffering from similar maladies.
    Article · May 2015 · Acta horticulturae
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    [Show abstract] [Hide abstract] ABSTRACT: Eighteen Prunus rootstocks budded with 'Redhaven' peach were planted at 16 locations in North America in 2009. After four years at 14 locations, significant differences among rootstocks and sites were found for survival, root suckers, growth, bloom date, fruit maturity date, fruit size, cumulative yield, and yield efficiency. Tree survival was high (>96%) in the states MA, CA, SC and UT and low (<78%) in MO and NC (bacterial canker). Imperial California had the lowest overall survival (48%) followed by Fortuna and Krymsk®1. Rootstock suckering was excessive on Prunus americana seedlings with Krymsk®1 a distant second. The largest trees were in CA, NY, MO and SC, while the smallest trees were in CO and UT, both high elevation mountain states with calcareous soils. Tree TCSAs were largest on Bright's Hybrid #5, Guardian®, Viking, Krymsk®86 and Atlas, whereas TCSAs of trees on Krymsk®1, Controller 5, P. americana and Fortuna were the smallest. The earliest bloom by 1-2 days in both years occurred on Bright's Hybrid #5 and KV010127 rootstocks. Trees on P. americana and Fortuna bloomed 1-3 days later than the average in 2011 and 2012. Fruit maturity dates varied by 59 and 52 days across sites in 2011 and 2012, respectively. Among rootstocks and years, fruit maturity was advanced up to 2.5 days and delayed as much as 3.5 days, when compared to Lovell. Bright's Hybrid #5 and KV010127 advanced maturity, and Penta and HBOK 32 delayed maturity in both years. Fruit size was largest (192 to 231 g) in SC, UT and CA and smallest (117 to 154 g) in GA and NC for both years. Empyrean®3, Atlas, Empyrean®2, Bright's Hybrid #5, Guardian® and Viking produced the largest fruit and Fortuna the smallest. Cumulative yields were highest in CA, NY, MO and MA and lowest in CO and IL. The highest yields were on the vigorous peach and peach hybrid rootstocks. Also, rootstocks with the highest yield efficiency were Krymsk®1, HBOK 10, P. americana, HBOK 32, and Controller™ 5.
    Full-text Article · May 2015 · Acta horticulturae
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    [Show abstract] [Hide abstract] ABSTRACT: Three peach cultivars, 'Crimson Lady' (early), 'Redhaven' (mid-season) and 'Cresthaven' (late), were planted at twelve locations within the USA in 2009. All trees were grafted on 'Lovell' rootstock and came from the same nursery. Five trees of each cultivar were planted at a spacing of 6 m by 5 m at each location. In 2012, eight locations were able to participate in the study. In order to obtain maximum fruit growth, trees were thinned to about 40-50 fruit within 30-40 days of bloom, were irrigated when needed and kept free of diseases and pests. When fruit started to soften (tree ripe), a first harvest was initiated. The second, and last, harvest occurred about one week later. Individual fruit were weighed and a composite sample per tree was used to measure percent soluble solids content (SSC) with a refractometer. Daily weather parameters of maximum and minimum temperatures, solar radiation, precipitation and average humidity were measured in close proximity to the orchard. Full bloom dates ranged from early March to early May for the different locations. Time from full bloom to harvest varied by about 30 days among locations for all three cultivars. This parameter correlated very well with average temperature (average of daily maximum and minimum) for 60 days after bloom. Correlation coefficients were -0.94, -0.96 and -0.98 for the three cultivars, respectively. Average fruit weight varied among sites from 141 g to 216 g for 'Crimson Lady', 159 g to 313 g for 'Redhaven' and 152 g to 413 g for 'Cresthaven'. This parameter correlated well with average solar radiation from bloom to harvest for 'Redhaven' (r = 0.87) and 'Cresthaven' (r = 0.73), but not 'Crimson Lady'. The relationship with 'Cresthaven' was significantly improved by adding in the factor of average temperature for 20 days after bloom (r2 = 0.91). Cooler temperatures were associated with larger fruit. No weather parameters correlated well with 'Crimson Lady' fruit weight or with SSC for any of the three cultivars. The study will continue for at least 2 more years to obtain more robust relationships.
    Full-text Article · May 2015 · Acta horticulturae
  • R. Odom · J.X. Chaparro · T.G. Beckman
    [Show abstract] [Hide abstract] ABSTRACT: Commercial peach is a highly homozygous self-compatible species with limited diversity. The incorporation of exotic germplasm and breeding of new varieties is hindered by the labor required to generate large segregating populations. Hand pollinations are characterized by a high failure rate with only 25% of pollinations resulting in fruit set. Additionally, peach fruit typically produce a single seed, further reducing the potential seedling population size. Two mechanisms that facilitate outcrossing, selfincompatibility and male sterility, exist in peach and closely related species. Fruit set in self-incompatible and male sterile genotypes is facilitated via insect pollination. In this presentation we describe procedures for the establishment and maintenance of a male sterility facilitated random mating breeding population.
    Article · May 2015 · Acta horticulturae
  • T.G. Beckman · J.X. Chaparro · P.J. Conner
    [Show abstract] [Hide abstract] ABSTRACT: The Southeastern US peach industry is concentrated in two production areas, i.e., central Georgia/South Carolina (high chill, main season) and the Lower Coastal Plain (moderate chill, early season) along the Gulf coast. These two areas have distinctly different climates and, consequently, require different priorities for the breeding of new peach cultivars. While the main season production areas in central Georgia and South Carolina have been supported for nearly 75 years by the breeding programs at the USDA-Byron location in central Georgia and Clemson University South Carolina, the lower coastal plain production area has never enjoyed focused breeding support and, instead, had to rely on the occasional 'spin-off' from other peach breeding programs, many of which are now shuttered. In 1991, a cooperative, moderate chill peach breeding program was established by the University of Georgia, the University of Florida and the USDA-Agricultural Research Service (Byron, Georgia) to address the unique needs of this industry. A novel aspect of this program has been its utilization of non-melting (i.e., "canning") flesh germplasm for the fresh market where melting flesh cultivars have traditionally reigned supreme. Non-melting flesh germplasm was utilized to take advantage of its slower rate of softening as fruit approaches maturity compared to melting types. This has made possible the breeding of peaches that can be harvested at a more mature stage, allowing the development of significantly improved eating quality, larger size and more red blush without sacrificing the firmness required for long distance shipping. To date, this program has released seven cultivars including five nonmelting peaches, several of which are being planted widely.
    Article · May 2015 · Acta horticulturae
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    Thomas G. Beckman · Jose X. Chaparro · Patrick J. Conner
    [Show abstract] [Hide abstract] ABSTRACT: A new and distinct variety of peach tree, denominated ‘Gulfsnow’, has a winter chilling requirement estimated at 400 chill units (cu). The tree is medium size, moderately vigorous, and semi-upright in growth habit. It bears showy, pink flowers, and leaves with globose glands. Trees of ‘Gulfsnow’ are self-fertile and regularly bear annual crops of early season fruit that are large size (185 g) for its ripening season. Fruit are uniformly firm with non-melting white flesh. Fruit are nearly round, and uniform with substantially symmetrical shape, and have an attractive 50 to 60% red skin. The fruit of ‘Gulfsnow’ usually ripen 10 days after ‘Gulfcrimson’ peach in early June at Attapulgus, Ga.
    Full-text Patent · Feb 2015
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    Dario J Chavez · Thomas G Beckman · Dennis J Werner · José X Chaparro
    [Show abstract] [Hide abstract] ABSTRACT: Peach is a self-pollinated species with a high level of linkage disequilibrium (LD) conservation for North American and European commercial varieties, LD~13-15cM. The analysis of the University of Florida peach germplasm founding clones, previous releases, and present selections, constitutes the main objective of this report. A total of 198 peach genotypes were fingerprinted with 37 SSRs distributed across the genome (~15-25 cM). Peach germplasm samples included genotypes from the University of Florida, the USDA-UGA-UF moderate-chill breeding effort, North Carolina State University, primitive low chill germplasm, and related species P. dulcis (Mill.) D.A. Webb and P. kansuensis Rehder. Number of alleles per locus (A), effective number of alleles (Ae), observed heterozygosity (Ho), expected heterozygosity (He), Wright’s fixation index (F), power of discrimination (PD), the probability of confusion (C), and Nei’s genetic distance (GD) per locus were calculated. An unrooted Neighbor-Joining tree was constructed using Nei’s genetic distance. ‘Diamante cling’, ‘Non-melting’, ‘Melting’, ‘High-chill’, and two ‘Nectarine’ clades were identified in the peach germplasm. Genetic diversity values in the range of 0.5 were observed. Past and present peach selections and cultivars developed by the UF breeding program have been determined by breeding strategies, objectives and commercial trends that changed through the years. To detect potential changes in allele frequencies resulting from the breeding efforts, the genetic diversity of germplasm representing different decades was compared.
    Full-text Article · Oct 2014
  • Jose X. Chaparro · Patrick J. Conner · Thomas G. Beckman
    Article · Aug 2014 · HortScience: a publication of the American Society for Horticultural Science
  • Mary Ann D. Maquilan · Mercy A. Olmstead · Jos X. Chaparro · [...] · Thomas G. Beckman
    [Show abstract] [Hide abstract] ABSTRACT: Peach production acreage in Central Florida is steadily expanding with the availability of new, high-quality, and low-chill requirement peach cultivars adapted to the region’s subtropical climate. Florida’s well-drained sandy soils are ideal for peach production except that they are also inhabited by plant pathogenic nematodes. ‘Flordaguard’ peach rootstock is recommended for commercial utilization because it is well-adapted to Florida’s acidic soils and exhibits good resistance to the endemic peach root-knot nematode, Meloidogyne floridensis (Mf). Additional nematode-resistant rootstocks are being identified to diversify the panel of improved rootstocks for the expanding peach industry. Two new rootstocks, ‘MP-29’ and ‘P-22’ (T. G. Beckman, USDA-ARS Byron, GA) offer potential for peach production in Central Florida. ‘MP-29’ is “pleach”, a hybrid between a red-leafed peach rootstock breeding selection and ‘Edible Sloe’ plum. The rootstock selection ‘P-22’ is a hybrid of ‘Guardian’ and ‘Flordaguard’ peach and is under consideration for release. A rootstock trial was planted at Citra, FL during the Spring of 2012 to test horticultural performance of these rootstocks with ‘Flordaguard’ in the presence of Mf. ‘Okinawa’ peach and ‘Barton’ peach rootstocks were included as susceptible and resistant controls, respectively. A commercial quality, low-chill peach scion, ‘UFSun’ was budded on all rootstocks to evaluate fruit quality. ‘MP-29’ clonal and ‘Barton’ seedling rootstocks were field-budded in 2012. ‘P-22’ clonal, ‘Okinawa’ seedling, and ‘Flordaguard’ seedling rootstocks were budded a year prior to field-transplanting in 2012. Scion growth was monitored one year after budding and fruits were harvested in the second season after establishment. Preliminary data indicate that the two new clonal rootstocks ‘MP-29’ and ‘P-22’ are promising alternatives to ‘Flordaguard’. During the two growing seasons, stem circumferences (2 inches below and above graft union) were significantly greater in ‘Okinawa’ and ‘P-22’ rootstocks. The relative growth rates of the scion were higher on field-budded ‘Barton’ and ‘MP-29’ rootstocks than those budded the previous year. ‘MP-29’ produced trees with yield efficiency and fruit size comparable to other tested rootstocks despite its smaller tree size – a characteristic useful for high-density planting systems. ‘Barton’ rootstock also demonstrates significant promise in terms of vigor (pruning weight and tree size) in the initial years of orchard establishment. Further evaluation is required to validate the effect of rootstocks on yield efficiency and resistance to Mf.
    Conference Paper · Jul 2014
  • [Show abstract] [Hide abstract] ABSTRACT: Prunus umbellata is a diploid plum species native to the Southern US with a wide geographic range and adaptation to different soils and environments. Other species native to the Southern US include P. americana Marsh., P. angustifolia Marsh., and P. geniculata Harper. The objective of this research was to evaluate P. umbellata as a model plant for the identification of genomic regions associated with dormancy response. A total of 48 genotypes: 42 of P. umbellata ranging from central Georgia to south Florida, 2 of P. americana, 2 of P. angustifolia, and 2 of P. geniculata, were fingerprinted using 41 SSRs distributed across the peach genome (~15-25 cM). Similarly, genotype-by-sequencing (GBS) was used to identify SNPs across the genome of 48 multiplexed genotypes using Illumina HiSeq® 2000 system. GBS produced up to 175 million reads in one flow cell lane, yielding approximately 40 Gb of data, with a filtered 101 million reads and an average of 2.1 million reads per genotype. SNP markers were detected using Stacks software and ranged from 30,411 markers (6x depth) for at least 33 genotypes (r=0.7 or 70% of genotypes required to process a locus) to 487 markers (6x depth) for all genotypes (r=1.0 or 100% of genotypes required to process a locus). Genetic diversity and population structure results based on SSR and SNP markers (using different depth coverage and r values) were comparable. SSR and SNPs markers allowed the identification of hybrid genotypes among species. Similarly, these markers were used to identify genomic regions associated with dormancy response.
    Conference Paper · Jul 2014
  • Thomas G. Beckman · Jos X. Chaparro
    [Show abstract] [Hide abstract] ABSTRACT: The primary focus of the USDA-ARS stone fruit rootstock program at Byron, Georgia has been the development of disease resistant rootstocks for peach. Historically peach tree short life (PTSL), aka ‘Bacterial Canker Complex’, and Armillaria root rot (ARR) have been the two most important causes of premature mortality of commercial peach trees in the southeastern United States. Several root-knot nematode species are of concern in this region as well. In addition to these disease issues the horticultural performance of trees on the new materials developed in this program is also of parmount importance. We have screened a broad range of Prunus germplasm and, in addition to useful differences in disease resistance, have found that these materials also have an impact on a number of important plant performance traits. Data will be presented on rootstock influence on tree vigor, anchorage, yield, fruit size, suckering and tree survival on disease prone sites.
    Conference Paper · Jul 2014
  • [Show abstract] [Hide abstract] ABSTRACT: Peach trees in the Southeastern United States are damaged by fungal gummosis (incited by Botryosphaeria dothidea [(Moug.:Fr.) Ces. & De Not.] with a fruit yield reduction up to 40% per tree in severe cases. Previous studies indicated a high level of susceptibility in commercially recommended rootstocks and cultivars. The climatic conditions in the Southeastern United States are conducive to the development of the disease and currently, there are no proven effective cultural or chemical controls for peach fungal gummosis. Our group has evaluated peach germplasm for over 2 decades, searching for sources of resistance to peach fungal gummosis. Preliminary research in our lab indicates that almond, a species closely related and sexually compatible with peach, may provide a new source of genes for resistance to peach fungal gummosis. Preliminary tests comparing commercial quality peach cultivars with peach x almond F1 hybrids indicated the existence of a novel source of resistance to gummosis. Parental genotypes and segregating backcross populations of peach, peach X almond F1 hybrids, and peach X (peach X almond) progeny were evaluated for 3 consecutive years using a previously established rating system based on gumming severity. Selected peach x almond F1 hybrids presented the lowest mean for gummosis susceptibility. Pearson chi-square analysis of the disease rating data suggested a dependent segregation of the populations for gummosis. Further analysis of the standardized residuals deviations identified differences in backcross population 8 (UFSharp x (Flordaguard x almond)). The phenotypic segregation ratio for fungal gummosis resistance is consistent with the presence of a single dominant locus. Backcross population 8 has been genotyped for SSR markers sourced from the Prunus reference genome map and Quantitative Trait Locus (QTL) analysis will be performed.
    Conference Paper · Jul 2014
  • Dario J. Chavez · Thomas G. Beckman · W. R. Okie · Jos Chaparro
    [Show abstract] [Hide abstract] ABSTRACT: North America is a center of diversity for Prunus L. species. The University of Florida Stone Fruit Breeding and Genetics Program in collaboration with the National Germplasm Repository and USDA–ARS (Project No. 5306-21000-018-00D) collected and identified ~400 genotypes of approx. 30 taxa native to the United States. A core collection of 13 species was used to compare the utility of selectively neutral sequences and sequences believed to be under selection pressure in the elucidation of phylogenetic relationships of North American plums. The core collection represented the major clades within subgenus Prunus section Prunocerasus. The American clade was represented by P. americana Marsh., P. hortulana L.H. Bailey, and P. mexicana S. Watson; the Chickasaw clade included P. angustifolia Marsh., P. munsoniana W. Wight & Hedrick, and P. umbellata Elliot; and the Beach clade was represented by P. geniculata Harper and P. maritima Marsh. Outgroups included: P. pumila L. (subgenus Cerasus section Microcerasus), P. persica (L.) Batsch cv. Okinawa, AP05-18ws (UF peach haploid), 02-01c (UF peach haploid) (subgenus Amygdalyus section Amygdalus), and P. fasciculata (Torr.) A. Gray (subgenus Emplectocladus). A total of 41 simple sequence repeat (SSR) markers distributed across the peach genome (~15–25 cM), 7 chloroplast genome regions, nuclear ribosomal repeat ITS, and 55 candidate genes believed to be associated with flowering and plant architecture were used. A Neighbor Joining (NJ) analysis of the SSR markers yielded different species relationships than the results obtained using chloroplast DNA (cpDNA) regions, internal transcribed spacer region (ITS), and nuclear genes Maximum Parsimony (MP) and Maximum Likelihood (ML) analyses. Phylogenetic analyses using cpDNA regions, ITS and nuclear genes yielded some of the previously known species relationships. A total of 27,278 bp of sequence per species was used. The observed polymorphism rates were 3.67%, 10.82%, and 7.27% for the cpDNA sequences, ITS, and nuclear genes, respectively. Sequence variation in exon and intron regions of nuclear genes was 4% and 11%, respectively. Several highly informative regions were identified that will be used for larger phylogenetic analysis within Prunus.
    Conference Paper · Jul 2013
  • Dario J. Chavez · Thomas G. Beckman · Jos Chaparro
    [Show abstract] [Hide abstract] ABSTRACT: North America is an important center of diversity for plum species. The North American plums grow in diverse climatic and geographic regions. High levels of variation for plant architecture, fruit size, flesh texture, flesh color, disease resistance, chilling requirement, and other traits, have been reported. The survival of several of these species is being negatively impacted by urban sprawl and agriculture. Similarly, climate change threatens their habitats. The objective of this research was to collect and identify plant specimens from the wild, create a herbarium and living collection that could be used to preserve the species and to clarify the phylogenetic relationships of the North American plums. The University of Florida Stone Fruit Breeding and Genetics Program in collaboration with the National Germplasm Repository and USDA–ARS (Project No. 5306-21000-018-00D) collected, identified and archived ~400 genotypes of approximately 30 taxa across the United States. Geographic coordinates, location descriptors, and plant characteristics were recorded for all these genotypes. Vouchers for each genotype were submitted and are available at the Florida Museum of Natural History, Gainesville, FL (http://www.flmnh.ufl.edu/herbarium/). Seed collected from the germplasm accessions were submitted to John E. Preece at the National Clonal Germplasm Repository for Fruit and Nut Crops, Davis, CA, for future use by the scientific community. These collections will allow us to preserve and conserve these species as important genetic resources of unique traits and information that could be used for breeding plum scions and rootstocks in the future. Additional information about this collection will be reported.
    Conference Paper · Jul 2013
  • Kendra M. Blaker · José X. Chaparro · Thomas G. Beckman
    [Show abstract] [Hide abstract] ABSTRACT: Dormancy is a condition that delays or inhibits growth in seed, vegetative buds, and floral buds. In peach, seed germination occurs when seed accumulate sufficient stratification and growing degree hours to break dormancy and begin growing. Correlations have been reported between mean seed stratification requirements and mean bud chilling requirements among Prunus families, but an individual seed’s germination date and subsequent vegetative and floral bud break date are not correlated. Prior to this study, the genetic factors involved in regulating seed dormancy and their location on the peach genomic map were unknown. Segregating F2 seed were collected from a high × low chill F1 peach hybrid in 2005, 2006, and 2008. Germination date and growth habit was measured after the stratification requirement of the 2005 seed was fully met. The seed collected in 2006 and 2008 received varying amounts of stratification, which enabled data on stratification requirement, heat requirement, and growth habit to be collected. Genomic DNA was extracted from seedling leaf tissue and screened with SSR markers selected from the Prunus reference map at an average resolution of 20 cM. Seed dormancy quantitative trait loci (QTLs) were detected on G1, G4, G6/8, and G7. The QTLs detected on G6/8 and G7 were discovered in the same region as QTLs associated with floral bud chilling requirement and bloom time in peach.
    Article · Jun 2013 · Tree Genetics & Genomes
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    Thomas G. Beckman · Jose X. Chaparro · Wayne B. Sherman
    [Show abstract] [Hide abstract] ABSTRACT: A new and distinct peach rootstock ‘MP-29’, which is an interspecific hybrid rootstock Prunus species hybrid×Prunus persica, which was developed for use as a clonal commercial rootstock under peach cultivars. It is distinguished by its resistance to peach tree short life/bacterial canker complex, Armillaria root rot, and to several species of root-knot nematodes.
    Full-text Patent · May 2013
  • T.G. Beckman · J.X. Chaparro · P.J. Conner
    Article · Jan 2013
  • T.G. Beckman · J.X. Chaparro · W.B. Sherman
    [Show abstract] [Hide abstract] ABSTRACT: Double flowering in peach [Prunus persica (L.) Batsch] has long been thought to be controlled solely by a single recessive gene (Di/di). Several hybrid populations were generated utilizing sources tracing to a single double flowered phenotype. Evidence is presented for two loci controlling double flowers. The first is the known single gene recessive and a second controlled by a single dominant gene. Data from several populations generated with the dominant locus and information on a followup survey and test crosses will be presented.
    Article · Oct 2012 · Acta horticulturae
  • J.X. Chaparro · O. Carillo · W.B. Sherman · T.G. Beckman
    [Show abstract] [Hide abstract] ABSTRACT: Mapping of traits in peach is hindered by the low heterozygocity encountered in peach × peach crosses. Typical heterozygocity rates in peach × peach crosses are in the range of 25-35% percent. The use of interspecific hybrids greatly increases the number of heterozygous markers in F1 hybrids and facilitates the making of genomic maps without blind regions. We have initiated the evaluation of Prunus kansuensis Rehder as a parent for genetic studies in peach. Peach × P. kansuensis F1 and F2 populations have been generated. F1 hybrids are vigorous, healthy and highly fertile producing large numbers of F2 seed. F2 seedlings are precocious with over 75% of seedlings producing flower buds by 18 months age. F2 seedlings show little evidence of inbreeding depression or hybrid breakdown.
    Article · Oct 2012 · Acta horticulturae

Publication Stats

355 Citations


  • 2013-2015
    • United States Department of Agriculture
  • 2008
    • Quincy University
      Куинси, Massachusetts, United States
  • 2000-2007
    • Clemson University
      CEU, South Carolina, United States
  • 2005
    • University of Florida
      Gainesville, Florida, United States
  • 2002
    • Michigan State University
      East Lansing, Michigan, United States