The
Beta vulgaris
complex includes sugar beet, mangel wurzel, Swiss chard, fodder beet, and table beet. Mangel wurzel and fodder beet are considered to be the same general crop type, with the former ...possessing lower dry matter content (<13%) than the latter. Mangel is likely derived from crosses between table beet and chard, while fodder beet may have a more recent origin, arising from crosses between mangel and sugarbeet. The table beet was derived from the wild sea beet,
B. vulgaris
(L.) subsp.
maritima
(L.) Arcang, with small non-spherical roots. Table beet is presently a popular vegetable cultivated for its pigmented roots, typically red but also yellow and other colors. Wild forms were consumed in antiquity mainly for their leaves with roots used medicinally. Beet is referred to in the Septuagint, a Greek translation of the first five books of the Hebrew bible, made in Ptolomeic Egypt in the third century BCE. A beet identified as
Beta maritima
is included in
De Material Medicus
of Pedanius Dioscorides written in the first century CE, and the first illustrated version of 512, known as the
Juliana Anicia Codex
, includes an image with non-spherical root. Beet is mentioned in several tractates of the Talmud, a sixth century collection of history and civil law written in Babylonia.
Beta maritima
possesses supernumerary root cambia, which facilitated selection of swollen rooted forms. The first colored illustration of swollen rooted table beet,
B. vulgaris
, can be found in the 1515–1517 frescos of Raphael Sanzio and Giovanni Martina da Udine in the Villa Farnesina in Rome. Swollen roots in Roman beet are illustrated and described in the 1587 French herbal
Historia Generalis Plantarum
of Jacques Dalechamps. Conically shaped beet roots are found in the market painting of Franz Snijders in the 17th century. Various spherical forms of beet root are found in the work of American painter James Peale in 1826. A complete array of beet root types is found in the Benary catalog of 1876. Modern, spherical beet roots were depicted in 1936 by the Russian painter Zinaida
Serebriankov, 1936
. Artistic and historical representations of table beet suggest that swollen rooted forms have existed during the past five centuries, but conically shaped roots were gradually replaced by spherically shaped roots during this period.
Bacterial leaf spot (BLS) has emerged in the last few decades as an economically important disease of both table beet ( Beta vulgaris ssp. vulgaris ) and Swiss chard ( Beta vulgaris ssp. cicla) . BLS ...is caused by Pseudomonas syringae pv. aptata , which is spread readily on infected seeds. Symptoms appear as circular to irregular shaped, with a tan to dark brown center and a very dark border. Disease incidence and severity is dependent on cool, humid conditions and can vary widely year to year depending on the environment. Both the vegetative and reproductive phases of these biennial crops are susceptible to the pathogen. Table beet and Swiss chard commercial cultivars (n = 21), table beet breeding lines (n = 5), and table beet plant introductions (PIs) (n = 26) were screened for response to spray inoculation with P. syringae pv. aptata in a controlled greenhouse setting. Plants were rated for severity of symptoms using percent of the area of each pair of leaves (leaf set) with symptoms and an overall plant score assigned based on the scores for each leaf pair. Accessions varied in BLS susceptibility. PI accessions were most variable, with the area under the disease progress curve (AUDPC) ranging from 1.33 to 8.75. Highly significant differences among PIs were detected for disease scores in the vegetative stage, beginning 21 days after inoculation. Screens during the reproductive growth stage showed the least variation in AUDPC among PIs. Although cultivars varied less than PIs, good BLS resistance (low disease scores) was noted for ‘Touchstone Gold’, ‘Kestrel’, ‘Bull’s Blood’, ‘Rainbow’ chard, as well as PIs 222234 and NSL 28026. Accessions W451C, Red Cloud, Detroit Dark Red, and NSL 28020 were highly susceptible. There was no consistent association between disease score in the vegetative and reproductive phases, suggesting that breeders may need to screen for BLS in both phases of the biennial life cycle. The more resistant PIs or cultivars identified in this study can be used in future efforts to breed for host resistance to BLS and to establish mapping populations to better understand the genetic control of resistance, to aid in breeding efforts.
Cercospora leaf spot (CLS), caused by the fungal pathogen Cercospora beticola , is the most destructive foliar disease of table beet ( Beta vulgaris ssp. vulgaris ) in Wisconsin, USA, and globally. ...Under conducive conditions, symptomatic lesions on the leaf expand and coalesce forming large necrotic areas that can ultimately lead to complete defoliation. This damage reduces productivity and threatens the ability to mechanically harvest. CLS damage also detracts from the visual appeal of fresh market bunched beets to such an extent that growers risk buyer rejection if CLS severity is observed to be greater than 5%. Fungicide use for CLS control is threatened by the emergence of resistant C. beticola strains, and the application of host resistance is constrained by limited knowledge of cultivar reaction to CLS in table beet. This study aimed to address the knowledge gaps of fungicide efficacy and cultivar reaction by conducting replicated field trials in multiple table beet growing environments across Wisconsin. Broad variation for resistance to CLS was observed among the 10 included cultivars. The mean area under disease progress curve (AUDPC) across environments for the most susceptible cultivar was 267% greater than the most resistant cultivar. Spearman correlations between environments for mean cultivar AUDPC value ranged from 0.71 to 0.99, revealing consistent cultivar CLS reactions across environments. Although susceptible cultivars surpassed 5% severity in all environments, the resistant cultivars remained below this threshold in six of the 10 environments. By comparison with resistant sugar beet ( Beta vulgaris ssp. vulgaris ) cultivars, however, all tested table beets appeared susceptible to CLS, highlighting the potential for a CLS breeding effort in table beet. Neither of the evaluated Organic Materials Review Institute–listed treatments were effective at limiting CLS disease progress, whereas both tested conventional fungicides significantly reduced disease severity over the nontreated plots. These findings may provide helpful guidance to table beet growers affected by CLS in Wisconsin and beyond.
Anthocyanins are red and violet pigments that color flowers, fruits and epidermal tissues in virtually all flowering plants. A single order, Caryophyllales, contains families in which an unrelated ...family of pigments, the betalains, color tissues normally pigmented by anthocyanins. Here we show that CYP76AD1 encoding a novel cytochrome P450 is required to produce the red betacyanin pigments in beets. Gene silencing of CYP76AD1 results in loss of red pigment and production of only yellow betaxanthin pigment. Yellow betalain mutants are complemented by transgenic expression of CYP76AD1, and an insertion in CYP76AD1 maps to the R locus that is responsible for yellow versus red pigmentation. Finally, expression of CYP76AD1 in yeast verifies its position in the betalain biosynthetic pathway. Thus, this cytochrome P450 performs the biosynthetic step that provides the cyclo-DOPA moiety of all red betacyanins. This discovery will contribute to our ability to engineer this simple, nutritionally valuable pathway into heterologous species.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Hybrid cultivars are valuable in many crop species due to their high yield, uniformity, and other desirable traits. Doubled haploids, which have two identical sets of chromosomes, are valuable for ...hybrid breeding because they can be produced in one generation, in comparison to the multigenerational process typically used to produce inbred parents for hybrid production. One method to produce haploid plants is manipulation of centromeric histone H3 (
CENH3
). This method of producing haploids has so far been successful in
Arabidopsis
, maize (
Zea mays
), and wheat (
Triticum aestivum
). Here we describe modification of
CENH3
in carrot (
Daucus carot
a) to test for the ability of these modifications to induce uniparental genome elimination, which is the basis for haploid induction. Base editing was used to make
cenh3
mutant plants with amino acid substitutions in the region of
CENH3
encoding the histone fold domain. These
cenh3
mutant plants were then outcrossed with
CENH3
wild-type plants. Using PCR-based genotyping assays, we identified two candidates for genome elimination. One candidate was classified as a putative aneuploid plant in which chromosome 7 is in a single copy state. The other candidate was characterized as a putative tetraploid that was likely haploid during its genesis. Our results suggest that this putative tetraploid inherited all of its chromosomes from the
CENH3
wild-type parent and that the genome of the
cenh3
mutant plant was lost. This study provides evidence that modification of
CENH3
in carrot has the potential to induce genome elimination and ploidy changes in carrot.
William Friedman (1891-1969), trained as a plant geneticist at Cornell University, was employed at Riverbank Laboratories by the eccentric millionaire George Fabyan to work on wheat breeding. ...Friedman, however, soon became intrigued by and started working on a pet project of Fabyan's involving the conjecture that Francis Bacon, a polymath known for the study of ciphers, was the real author of Shakespeare's plays. Thus, beginning in ∼1916, Friedman turned his attention to the so called "Baconian cipher," and developed decryption techniques that bore similarity to approaches for solving problems in population genetics. His most significant, indeed pathbreaking, work used ideas from genetics and statistics, focusing on analysis of the frequencies of letters in language use. Although he had transitioned from being a geneticist to a cryptographer, his earlier work had resonance in his later pursuits. He soon began working directly for the United States government and produced solutions used to solve complex military ciphers, in particular to break the Japanese
code during World War II. Another important legacy of his work was the establishment of the Signal Intelligence Service and eventually the National Security Agency.
Increased use of intellectual property rights over plant germplasm has led to a complicated landscape for exchange among plant breeders. Our goal was to examine phenotypic and genotypic diversity ...present in commercially available carrot (Daucus carota L. var. sativus) germplasm in relation to the freedom to operate-the ability for plant breeders to access and use crop genetic diversity. A collection of 140 commercially available carrot cultivars were grown in replicated field trials in the Madison, WI area in 2013 and 2014. Phenotypic measurements were recorded for leaf and root characteristics. Illumina sequencing was used to conduct genotyping by sequencing analysis on all cultivars to understand the range of genetic diversity present. Additionally, the intellectual property rights associated with each cultivar was noted to determine the freedom to operate. We found that although one-third of the commercially available US carrot cultivars in our study are restricted through some form of intellectual property rights, the genetic and phenotypic variability of the protected cultivars does not represent a completely separate group from the available material. Phenotypic analyses including ANOVA and principal components analysis, suggest that many of the traits differed significantly based on market class, but not by whether the cultivar had freedom to operate. The principal components and Fst analyses on the genotyping by sequencing data revealed that carrot market classes (Fst = 0.065) and freedom to operate classes (Fst = 0.023) were not genetically distinct, and that principle components 1 and 2 account for only 10.1% of the total genotypic variation, implying that cultivated carrot germplasm in the US forms an unstructured population. Our findings suggest that the genetic diversity present in carrot cultivars that have freedom to operate is potentially large enough to support carrot breeding efforts in most market classes given present levels of intellectual property protection.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
For millennia, seeds have been freely available to use for farming and plant breeding without restriction. Within the past century, however, intellectual property rights (IPRs) have threatened this ...tradition. In response, a movement has emerged to counter the trend toward increasing consolidation of control and ownership of plant germplasm. One effort, the Open Source Seed Initiative (OSSI, www.osseeds.org), aims to ensure access to crop genetic resources by embracing an open source mechanism that fosters exchange and innovation among farmers, plant breeders, and seed companies. Plant breeders across many sectors have taken the OSSI Pledge to create a protected commons of plant germplasm for future generations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Consumers perceive flavor as a critically important attribute of vegetable crops. Gas chromatography-mass spectrometry (GC-MS), spectrophotometry, and refractometry of tissue samples collected during ...multiple years from table beet ( Beta vulgaris ) at various stages of maturity were performed to characterize the endogenous production of geosmin, oxalic acid, and total dissolved solids within the root. The geosmin concentration was primarily influenced by the cultivar and peaked early during the growing season, with root concentrations at 6 weeks after planting that were 312% higher, on average, than those found in harvest stage roots at 15 weeks after planting. The highest average concentration of geosmin in harvest stage roots was detected in tissue from the cultivar Bull’s Blood (16.08 μg⋅kg −1 ). The oxalic acid concentration showed a strong cultivar influence and statistically significant variability across the growing season. Hybrid beet cultivar Boro had the lowest soluble oxalic acid concentration (95.73 mg⋅100 g −1 fresh tissue) at all locations and during all years. The oxalic acid concentration peaked 12 weeks after planting, and it was lower at the postharvest sampling date 18 weeks after planting. Total dissolved solids (TDS) concentrations were strongly influenced by year and growing environment and displayed crossover interactions for environment × week. TDS measurements had a moderate negative correlation with root mass. ‘Chioggia Guardsmark’ consistently had the highest TDS during all years and at all locations at 12.01 °Brix. The TDS varied significantly according to time, and diurnal sampling revealed fluctuations as large as 4 °Brix over the course of a 12-hour period. The TDS concentrations increased throughout the growing season, although the rate at which they increased changed according to plant age. The results from this study suggest that interactions between cultivar, time, and environment are important determinants of oxalic acid and TDS concentrations, but they have less influence on geosmin. This information may influence the methods that plant breeders use to collect phenotypic data of important flavor compounds in beets.
Carrots are among the richest sources of provitamin A carotenes in the human diet, but genetic variation in the carotenoid pathway does not fully explain the high levels of carotenoids in carrot ...roots. Using a diverse collection of modern and historic domesticated varieties, and wild carrot accessions, an association analysis for orange pigmentation revealed a significant genomic region that contains the
gene, advancing it as a candidate for carotenoid presence in carrot. Analysis of sequence variation at the
locus revealed a nonsynonymous mutation cosegregating with carotenoid content. This mutation was absent in all wild carrot samples and nearly fixed in all orange domesticated samples.
has been found to control carotenoid presence in other crops but has not previously been described in carrot. Our analysis also allowed us to more completely characterize the genetic structure of carrot, showing that the Western domesticated carrot largely forms one genetic group, despite dramatic phenotypic differences among market classes. Eastern domesticated and wild accessions form a second group, which reflects the recent cultivation history of carrots in Central Asia. Other wild accessions form distinct geographic groups, particularly on the Iberian peninsula and in Northern Africa. Using genome-wide
, nucleotide diversity, and the cross-population composite likelihood ratio, we analyzed the genome for regions putatively under selection during domestication and identified 12 regions that were significant for all three methods of detection, one of which includes the
gene. The
domestication allele appears to have been selected after the initial domestication of yellow carrots in the East, near the proposed center of domestication in Central Asia. The rapid fixation of the
domestication allele in almost all orange and nonorange carrots in the West may explain why it has not been found with less genetically diverse mapping populations.
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