International Journal of Agriculture and Crop Sciences.
Available online at www.ijagcs.com
IJACS/2013/6-3/151-156
ISSN 2227-670X ©2013 IJACS Journal
Evaluation of genetic diversity in Iranian yellow
carrot accessions (Daucus carota var. sativus), an
exposed to extinction rooty vegetable, using
morphological characters
Mohammad Reza Kasiri1*, Mohammad Reza Hassandokht2, Abdolkarim Kashi2, Ali ShahiGharahlar3
1. MSc of Horticultural Sciences, Graduated from Department of Horticultural Sciences, University of Tehran, Karaj
31587-77871, Iran
2. Faculty of Agriculture, University of Tehran, Karaj 31587-77871, Iran
3. PhD Student of Horticultural Sciences, Department of Horticultural Sciences, Faculty of Agriculture, University of
Tehran, Karaj 31587-77871, Iran
Corresponding author email: [email protected]
ABSTRACT: Yellow carrots (Daucus carota var. sativus) have a long history of cultivation in Iran. They
have desirable characters such as resistance to heat, drought, salinity, pests and diseases. The aim of
this study was to evaluate morphological characters of Iranian yellow carrot accessions, a forgotten rooty
vegetable and exposed to extinction to use in future breeding programs. Cluster analysis separated
accessions into three main groups, two Asian and one European group. In this study, Iranian yellow
carrots were belonging to Asian group that they had properties such as yellow roots, gray-green leaf with
dense hair and slightly or intermediate dissection and celery or parsley leaf type. Heaviest (610 g) and
longest (31.5 cm) root was belonging to Naein accession. Tabas accession had thickest root (83 mm),
outer and inner core (23.2 and 45.3 mm, respectively) and lowest ratio of inner core diameter to total
diameter. Factor analysis categorized the evaluated characters into 12 main factors that these factors
accounted for over than 95 % of total variance. Results of simple correlation among characters showed
the existence of significant, positive and negative correlations in root and leaf. The results of this study
showed a high diversity among Iranian yellow carrots and that they are invaluable genetic resources for
breeding programs.
Key words: Carrot, Morphological diversity, Accession, Yellow carrot, Cluster analysis
INTRODUCTION
Carrot (Daucus carota var. sativus) is a biennial vegetable in the family of Apiaceae. This vegetable is
among the top-ten most economically important vegetable crops in the world (Simon et al. 2008) and it is the most
widely grown and important vegetable of the Apiaceae (Rubatzky et al. 1999). Carrot, including feral and
domesticated forms, has wide phenotypic and molecular variation (Simon 2000).
Cultivated carrots are divided into two groups: (1) Asian group that has traits such as yellow or purple root
color, slightly soft texture, low sweet, pubescent leaves which give a green gray appearance, bolt easily, adapted to
warm temperature; and (2) European group that has orange, yellow, red or white root in color, firm textured, sweet,
less pubescent green leaves, slow bolting and acclimated to cool temperature (Rubatzky and Yamaguchi 1997).
Root color is observed as orange, yellow, red, purple and white. Orange carrots contain predominantly βcarotene (45-80%) accompanied by α-carotene that together constitute up to 95% of total carotenoids. In yellow
carrot, lutein and β-carotene are mainly found, but traces of α-carotene are also reported. Significant amounts of
lycopene are present only in red roots that contain also β-carotene while α-carotene is usually below the detection
limit. Purple roots can possess a similar carotene composition as orange roots, but the presence of dark
anthocyanins masks the orange color (Malgorzata et al. 2006). White carrot lack pigment (Rubatzky et al. 1999).
Intl J Agri Crop Sci. Vol., 6 (3), 151-156, 2013
The first widely accepted evidence of cultivation of modern day carrot comes from Iran and Afghanistan in
tenth-century, where cultivation of this rooty vegetable spread throughout Asia and Europe (Bradeen and Simon
2007).
Yellow carrots in Iran are called 'Zardak' (that means yellow like), 'Gazar' or 'Gezer' (arabicized of Gazar
and Gezer are Jazar and Jezer) and 'Havij Irani' (that means Iranian carrot). Yellow carrots consumed in different
forms such as boiled with beet and turnip in the winter, raw, juice, pickles, jam and in different foods such as soup,
porridge, broth and as food for live stock. Yellow carrots are good resources of antioxidants and provitamin A. Anti
microbial influences of Iranian yellow carrot were proofed on Listeria monocytogenas and its influences have been
more than orange carrots (Haji Seyed Javadi et al. 2009).
Yellow carrots had been adapted to ecological conditions of Iran (heat, salinity and drought) (Figure 1) and
had been resisted to pests and diseases in long period of cultivation (personal communication). Nowadays yellow
carrots cultivate in small area production in some provinces such as Isfahan, Yazd, Qom, South Khorasan,
Kerman, etc.
Since information on evaluation of genetic diversity of Iranian yellow carrots were not adequate and
existent landraces are exposed to danger of extinction, present study was carried out: 1) to prepare a collection of
Iranian yellow carrots, 2) to evaluate genetic diversity using morphological characters, 3) to assign geographical
distribution of Iranian yellow carrot and 4) to introduce desirable accessions for production.
MATERIAL AND METHODS
Seeds of 13 accessions Iranian yellow carrot and three accessions of local orange carrot were collected
from different provinces (Table 1 and Figure 2). These accessions together with two control cultivars, an orange
carrot (Nantes) and a Dutch yellow carrot (Aviflora), were sown at Tehran University Experimental Research
Station in May 2009. The experimental design was completely randomized block design with three replications and
20 plants per each replication. Twelve mature plants (four plants per each replication) were selected from middle of
rows for evaluation of morphological traits. Fifty-three morphological traits were evaluated according to IPGRI
descriptor (Descriptors for Cultivated and Wild Carrots 1998). Petiole thickness, root diameter, outer core thickness
and inner core diameter were measured by a digital caliper (Mitutoyo Co. Japan). In addition to IPGRI traits, other
traits including lightness, hue, chroma, and dry matter, ash and TSS also were evaluated. Color traits were
measured by a chromameter (Konica Minolta Co. Japan). The total solid soluble (TSS) was measured by a
°
refractometer (Atago Co. Japan). Dry matter was done by an oven (at 60 C and period of 48 hours). Ash was done
°
by an electric oven (at 600 C and period of 8 hours). Analysis of variance, simple correlation analysis, factor
analysis and cluster analysis were done by SPSS software ver.16. Means were compared using the Duncan's
multiple range tests. Factor analysis was done by Varimax method. In each main factor, factor coefficients more
than 0.6 are account significance. Cluster analysis was done by Ward’s method.
RESULTS AND DISCUSSION
Analysis of Variance
Analysis of variance for quantitative traits showed that accessions had significant differences among these
traits. Nantes cultivar produced shortest and the most narrow leaves (18.4, 19 cm), while Sanandaj and Bidhand
accessions produced widest (38.65 cm) and longest (31.8 cm) leaves, respectively. Nantes cultivar and Qom
accession had lowest (3 mm) and highest (5.6 mm) petiole thickness, respectively. Maximum and minimum
number of leaves related to Khorzuq and Bidhand accessions (16.4 and 5.7, respectively).
Naien accession produced heaviest and longest root (610g, 31.5 cm), while Khorzuq accession had
lightest root (83.6 g) and Birjand accession had the shortest root (18.7 cm). Root length in carrot range from five to
more than 50 cm; between 10 and 20 cm is most common. Roots longer than 30 cm are difficult to harvest and
handle. But yield potential increases with root length (Rubatzky and Yamaguchi 1997). Whole of accessions had
root thickness smaller than 10 cm. Widest root related to Tabas accession (83 mm), it also had highest outer and
inner core thickness (23.2, 45.3 mm respectively) and lowest ratio of inner core diameter to total diameter (1.75).
Root diameters vary from one to more than 10 cm (Rubatzky and Yamaguchi 1997). Most narrow inner and outer
core was belonging to Hossein Abad accession (16 mm) and Nantes cultivar (6 mm), respectively. Highest ratio of
inner core to total diameter related to Dowlat Abad accession (3.13).
Aviflora cultivar had the most TSS (14.7%) and dry matter (15.2%), while Shahr Babak and Naien
accessions had the least TSS (4.4%) and dry matter (7.67%), respectively. The average measured dry matter
(11.55%) was a little less than what USDA (2009) reported (11.71%). Ash was maximum (1.3%) in Khorzuq and
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Intl J Agri Crop Sci. Vol., 6 (3), 151-156, 2013
Hossein Abad accessions and minimum (0.6%) in Deligon accession. The average measured ash (0.95%) was a
little less than what USDA (2009) reported (0.97%).
Simple Correlation Analysis
Results of simple correlation analysis showed significant, positive and negative correlations among some
important characters. There was a positive correlation between primary leaflet length and mature leaf width (r=
+0.91). Number of leaves had positive correlations with foliage coverage and foliage width (r= +0.61 and r= +0.82,
respectively). Leaf and petiole hairiness had a negative correlation with leaf dissection (r= -0.76) and positive
correlation with leaf color (r= +0.81) and leaf color intensity (r= +0.81). Red color in shoulder had a positive
correlation with extent of anthosyanin in petiole (r= +0.47). Number of days for bolting showed negative correlations
with bolting tendency and bolting rate (r= -0.83).
Root diameter showed positive correlations with root weight, outer and inner core thickness, and root
length ratio to root diameter (r= +0.84, r= +0.75, r= +0.85 and r= +0.81, respectively) and negative correlation with
dry matter percent (r= -0.65). Also root weight had a negative correlation with dry matter percent (r= -0.63), while it
had positive correlations with outer core thickness and inner core diameter (r= +0.77 and r= +0.85, respectively).
There were a positive correlation between outer core thickness and inner root diameter (r= +0.71). Outer core
thickness showed a negative correlation with TSS percent (r= -0.63).
Factor Analysis
Factor analysis categorized the evaluated characters into 12 main factors that these factors accounted for
over than 95% of total variance. Factor one related to traits such as petiole and leaf hairiness, leaf color intensity,
outer core thickness, foliage coverage, number of leaves, petiole thickness and root position in soil with positive
coefficients and petiole shape, inner core color, TSS, leaf dissection and leaf type with negative coefficients. This
factor explained 17.25 % of total variance.
Some traits such as root diameter, root length relative to root diameter, inner core diameter, root weight,
with positive coefficients are placed in factor two which accounted for 13.74% of total variance.
Factor three related to traits such as inner core color, root skin color, anthocyanin coloration in petiole,
extent of red color in shoulder and leaf type and it explained 9.56% of total variance. Some traits such as bolting
tendency, bolting rate, hue of root skin and leaf length related to factor four. Root surface, homogeneity of core and
flesh pigmentation placed in factor five. Ratio of core root diameter to total diameter, flesh color distribution in
transverse section, flesh palatability, ash percent, flesh color intensity, root length, extent of green color on
shoulder are placed in factor six to 12, respectively.
Cluster Analysis
Cluster analysis (Figure 3) based on these 12 factors divided these accessions into three groups. Group A
included Asheq Abad, Dowlat Abad, Shahr Babak, Khorzuq, Deligon, Aran & Bidgol, Qom, Bidhand and Birjand
accessions. This group had characters such as dark yellow root (except Bidhand accession), gray-green,
pubescent, slightly and intermediate (Bidhand and Birjand) dissected leaves with celery or parsley (Birjand
accession) type, intermediate bolting tendency and bolting rate (except Qom accession which had high bolting
tendency and fast bolting rate).
Group B included Naien, Kharanaq, Nehbandan and Tabas accessions. These accessions produced light
yellow root, gray-green, pubescent, intermediate dissection and celery or parsley (Nehbandan) type leaves,
intermediate and low (Kharanaq) bolting tendency and bolting rate. Accessions of this group had the heaviest roots
among accessions.
Group C included Hossein Abad, Haji Abad, Sanandaj accessions and Aviflora and Nantes cultivars.
These accessions had characters such as yellow (Aviflora) and orange (Haji Abad, Hossein Abad, Sanandaj and
Nantes) roots, green leaves with sparse hairiness and highly dissected and normal type, low (Aviflora and Nantes)
and intermediate (Haji Abad, Hossein Abad, Sanandaj) bolting tendency and bolting rate.
Evaluation of morphological traits showed that groups A and B are related to Asian (eastern) carrots
(Figure 4) and group C is related to European (western) carrots. This classification is observed in distance of 25 for
similarity coefficient in Figure 3. Groups A and B differ in root color intensity and root weight. Group A had dark
yellow root and light root (mean: 198.96 g), while group B had light yellow carrot and heavy root (mean: 511.31 g).
Groups A and B are reminders of Iranian yellow carrot landraces that remained from long period of
cultivation and any breeding programs weren't been done on them. In addition to having desirable characters such
as resistance to heat, salinity, drought, pests and diseases, they have some other noticeable traits. For example,
Kharanaq accession had positive characters such as low bolting tendency, low bolting rate, high uniformity of root
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type and root size, low root branching, high flesh palatability, etc without any breeding program on it. This
accession merits for introducing as a variety.
Results of cluster analysis also showed that collected samples from one province don't place in a same
group. For example, samples of Isfahan province are observed in both group A and B. (Asheq Abad, Dovlat Abad,
Khorzuq, Deligon and Aran & Bidgol in group A and Naien in group B).
For hybridization programs are better that we select the parents from which are further than each other in
cluster analysis. For example, crossing between Asheq Abad accession (group A) and Haji Abad accession (group
C: European carrots) will have better results probably. We can cross the Asheq Abad accession (group A) with
Tabas accession (group B) disinclination to crossing European carrots.
As a conclusion, this study showed that Iranian yellow carrots have a high morphological genetic diversity.
This provides a good germplasm for breeding goals, especially for releasing of varieties with high adaptation to
Iran’s climate (hot and dry). Also desirable characters of these valuable genetic resources can be transferred to
optional varieties by hybridization and genetic engineering techniques. Also results of this study shows Iranian
yellow carrots in this study were belonging to Asian carrots. In addition, conservation and maintenance of these
valuable genetic resources is highly recommended.
Figure 1. Resistance of Iranian yellow carrot to salinity (Shahr Babak, Kerman province). Ground has been white because of
salt.
Figure 2. Map of Iran locations. Collection sites of studied accessions (yellow or orange root) have been shown by
and
in six provinces.
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Intl J Agri Crop Sci. Vol., 6 (3), 151-156, 2013
Figure 3. Dendrogram of Iranian yellow carrot accessions using Ward’s method.
Figure 4. Iranian yellow carrot accessions used in this study
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Table 1. Studied accessions with their root color, collection place and geographical information
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Root
Color
Iranian
yellow
carrots
Local
orange
carrots
Accession
Province
Aran & Bidgol
Naien
Khorzuq
Deligon
Asheq Abad
Dowlat Abad
Bidhand
Shahr Babak
Nehbandan
Birjand
Qom
Tabas
Kharanaq
Haji Abad
Hossein Abad
Sanandaj
Isfahan
Isfahan
Isfahan
Isfahan
Isfahan
Isfahan
Isfahan
Kerman
South Khorasan
South Khorasan
Qom
Yazd
Yazd
Yazd
Yazd
Kordestan
Latitude
(°)
34/05
32/86
32/77
32/74
32/66
34/10
33/51
30/10
31/56
32/89
34/64
33/59
32/35
31/72
31/66
35/31
Longitude
(°)
51/48
53/09
51/64
51/66
51/67
51/47
51/78
55/12
60/07
59/24
50/88
56/92
54/68
53/93
53/98
46/99
Altitude
(m)
911
1572
1527
1571
1566
878
2416
1874
1214
1503
925
652
1637
2079
2397
1464
REFERENCES
Bradeen JM, Simon PW. 2007. Vegetables. In: Chittranjan K (ed) Genome Mapping and Molecular Breeding in Plants, Springer
Dehkhoda A. 1940-1980. Dehkhoda Dictionary. Tehran University Publishing
Haji Seyed Javadi N, Valaei N, Jamshidian M, Akhtari L.2009. Comparision of antimicrobial effect of Zardak and Daucus carota on Listeria
monocytogenes. Pejouhandeh 67:9-14
IPGRI. 1998. Descriptors for Wild & Cultivated Carrots. International Plant Genetic Resources Institute, Rome, Italy, 65 pp
Malgorzata B, Rafal B, Hartwig S. 2006. Tissue-specific accumulation of carotenoids in carrot roots. Planta 224:1028–1037
Rubatzky VE, Quiros CF, Simon PW. 1999. Carrots and Related Vegetable Umblifere. CABI Publishing, 294 p
Rubatzky VE, Yamaguchi M. 1997. World Vegetables, Principal, Production & Nutritive Values. Champan & Hall, International Thompson
Publishing, New York
Simon PW, Freeman RE, Viera JV. 2008. Carrots: Handbook of Plant Breeding. In: Prohence J, Nuez F (ed) Vegetables II. Springer
Simon PW. 2000. Domestication, historical development, and modern breeding of carrot. Plant Breeding Reviews 19:157-190
USDA. 2009. National Nutrient Database for Standard References. Nutrient Laboratory Home Page. http://www.nal.usda.gov/fnic/foodcomp/cgibin/measure.pl
156