under various abiotic stresses, where DcHsp17.7 in carrot ( Daucus carota L.) was expressed under conditions of heat ( Kim and Ahn, 2009 ), cold ( Song and Ahn, 2010 ), and salinity ( Song and Ahn, 2011 ). Furthermore, the heterologous expression of
Center for Biotechnology Information (NCBI) accession no.: NC_000913.2] promoter, an Hsp17.7 gene from carrot ( Daucus carota L.; NCBI accession no.: X53851) and flippase-recombinase targets (Frt) cassette were generated by polymerase chain reaction
Carrot ( Daucus carota L.) is a cross-pollinating, diploid (2 n = 18), biennial root vegetable belonging to the Apiaceae. It ranks among the top-ten vegetable crops globally and is an important source of prebiotics, minerals, fiber, and especially
A sample of 124 Daucus carota L. accessions, including cultivated carrot [D. carota ssp. sativus (Hoffm.) Arcangeli] and related wild subspecies, using a variety of molecular markers was examined. Represented within the samples were wild accessions from 18 countries, 14 of 16 major root types of European origin, and examples of major North American and Asian cultivated carrot types. Amplified fragment length polymorphism (AFLP) and inter-simple sequence repeat (ISSR) markers revealed extensive variation within D. carota. Although cultivated carrot and wild D. carota subspecies can cross freely, cultivated and wild carrots clustered separately, supporting the possibility that human selection for desirable horticultural traits has artificially reduced gene flow between cultivated and wild forms. Our analyses support the likelihood that North American D. carota populations arose due to introduction of weedy materials rather than escape of cultivated forms. With the exception of wild vs. cultivated types, no genetic alliances were evident in dendrogram topology. Furthermore, between and even within nonmapped marker classes, dendrogram topology predictions were not consistent. Generally poor correlations among root types, geographic origin, mitochondrial, plastid, and specific nuclear diversity and AFLP/ISSR data were also observed. We concluded that genetic diversity in carrot is extensive and relatively nonstructured in nature.
Parts of Colorado receive more hail than almost any other area in the nation. Severe storms can injure crop tissue and, thus, lower yield and predispose the crop to disease infection. Our study was conducted to determine the yield and quality response of carrot (Daucus carota L.) to simulated storm damage during different periods of plant development. We removed 33% and 67% of the carrot foliage at four dates, spaced 10 days apart, during the middle of the growing season. In 1997 and 1998, 67% defoliation significantly reduced total and marketable yields more than did 33% defoliation. Total yield components, length and diameter, were similarly affected. Defoliation, in general, decreased yield the greatest when it when it occurred at the later stages of development. Carrot foliage continued to develop and grow after all defoliation events. Nonetheless, moderate (33%) and severe (67%) foliage loss reduced marketable yield and yield components of carrots.
Secondary metabolite production by plant cell culture has been become of interest because of its commercial value in use. However, cultured plant cells usually yield lower levels of secondary metabolites than those of intact plants. In order to improve the anthocyanin productivity in hairy root culture of Daucus carota, fungal elicitors from 8 species of Fungi were examined. Through the studies of fungal elicitors in this work, it was turned out that fungal elicitors were very effective to improve the yield of anthocyanin. Despite of its low yield of anthocyanin, high density culture of hairy roots is achieved in fluidized-bed bioreactor, Anthocyanin production in fluidized-bed bioreactor with fungal elicitor treatment was increased greatly. We are currently researching more detailed aeration effects and scale-up in air-lift bioreactors. And these studies could provide important data to establish mass production system for secondary metabolites.
The root-knot nematode (M. hapla Chitwood) poses a threat to carrot (Daucus carota L.) production in the United States. Little information is available concerning the genetic control of nematode resistance in carrot. Crosses between two inbreds, a resistant genotype (R1) and susceptible genotype (S1) identified in previous screening tests of carrot were studied in the F2 and BC1 generations to determine the heritability of resistance to the root-knot nematode. Seedlings of F2 (R1/S1), BC1S1, and BC1R1 generations were evaluated for their responses to infestation of M. hapla Chitwood based on gall number per root, gall rating per root, and root rating per root in a greenhouse experiment conducted during 1994. Narrow-sense heritabilities were calculated according to the method of Warner (1952). Narrow-sense heritability was 0.16 for resistance based on gall number, 0.88 for resistance based on gall rating, and 0.78 for resistance based on root rating. This information may be of importance to geneticists and carrot breeders for the development of nematode-resistant carrot cultivars.
The influence of calcium (Ca++) nutrition on the growth and root tissue electrolyte leakage (EL) of carrot (Daucus carota) was investigated using a hydroponic culture system. Seedlings of `Navajo' carrot were grown for 10 weeks with roots submersed in hydroponic nutrient solutions containing 0, 0.1, 1, 2, 4, or 8 meq/L Ca++. The nutrient solution was replenished weekly with its pH maintained at 5.8 for the entire experimental period. The tap root lengths increased as solution Ca++ concentration increased. The diameter and fresh and dry weights of the tap roots increased as Ca++ concentration increased up to 4 meq/L, and then decreased at 8 meq/L Ca++. The root and petiole concentrations of sugar, potassium, and nitrate were unaffected by changes in nutrient solution Ca++ levels. The tissue EL, when tested for the stored roots, decreased as solution Ca++ concentration increased (r = 0.602). Results of this experiment suggest that calcium nutrition is essential for maintaining cell wall integrity in hydroponically grown carrot roots.
Abstract
The genetic control of root color and carotenoid synthesis in carrot, Daucus carota L., was studied using 3 carrot cultivars, Kintoki Heian Nagabuto, KHN: Kintoki Osaka, KOS: Kintoki Davis, KDA, and 1 inbred line (W93). Genetic models describing the inheritance of red roots in the F2 were tested in backcross and F3 progenies. In Kintoki cultivars the major pigment is lycopene; beta-carotene is present in smaller amounts; zeta-carotene, gamma-carotene and phytofluene were also detected. In W93 the main pigments are beta-carotene and alpha-carotene; zeta-carotene, gamma-carotene and phytofluene also are detected. The pigments were separated into carotene and carotenol fractions by partition column chromatography. The pigments in the carotene fraction were studied qualitatively and quantitatively by thin layer chromatography. Orange (W93) was dominant to red (KHN, KOS, KDA) in the F1 progeny. The F2 segregation indicated that at least 2 genes are responsible for the differences between orange and red. The segregation of F3, backcrosses, and other progenies revealed the existence of dominant red as well as dominant orange, supporting the digenic composition of F2 populations and indicating the locus with the dominant orange allele to be epistatic to the locus with the dominant red allele. The homozygous recessive would be orange also. The analysis of progenies from the crosses W93 × ‘Kintoki’ suggested a dominant gene for accumulation of alpha-carotene in W93 and a dominant gene for the accumulation of lycopene in ‘Kintoki’.
the productivity of most vegetables have yet not been well-characterized ( Fahad et al., 2017 ; Mahmood et al., 2017 ). It may be anticipated that cool-season vegetables, like carrot, are especially sensitive to heat stress. Carrot ( Daucus carota L