Evaluation of Drought Tolerance of Potato Cultivars Under Greenhouse Conditions

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Evaluation of Drought Tolerance of Potato
Cultivars Under Greenhouse Conditions

• Sultan F. Alsharari and Abdullah A. Alsadon

Department of Plant Production College of Food
and Agricultural Sciences King Saud
University P.O. Box 2460 Riyadh 11451 Saudi
Arabia
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Introduction

• Potato is characterized as a drought sensitive
  crop.
• Drought conditions resulted in reduced vegetative
  growth, leaf area and plant height.
• Many studies have illustrated the effect of
  drought treatments on low tuber yield in
  potatoes. Tuber quality can also be affected.

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Introduction

• Fresh Tuber yield was significantly correlated to
  root dry mass which was reduced by drought.
• Proline content in the leaves is a key factor in
  determining drought tolerant or sensitive
  cultivars.
• Water stress in the field or greenhouse has
  resulted in an increase in proline content in
  potato tubers.
• From the previous studies, it is clear that
  drought has a major role in decreasing potato
  productivity and quality.

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Objective

• The objective of this study was to evaluate
  growth and productivity of some potato cultivars
  in response to drought treatments under
  greenhouse conditions.

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Materials and Methods

• Seed potatoes of seven cultivars were obtained
  from local agricultural companies which commonly
  grow them for fresh or processing purposes.
• These cultivars represent a selection of maturity
  groups and tuber characteristics (Table 1).

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Table 1 Maturity type and tuber traits of seven
potato cultivars selected in this project
Sources
1- Canadian Food Inspection Agency, Plant
Products Directorate, Plant Health Division,
Potato Section (www.inspection.gc.ca/english/plave
g/potpom/var) 2- Nivaa Holland (www.aardappelpagin
a.nl/index.html) 3- Le Plant De Pomme De Terre
(The French varieties) (www.plantdepommedeterre.or
g/eng/var.asp)
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Hermes
Sandy
Mondial
Safrane
Asterix
Victoria
Rosetta
Plate 1. Tuber traits of eight potato cultivars
selected in this project.
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Materials and Methods

• Clonal propagation started from excised shoot
  apices of growing sprouts.
• Several multiplication cycles were carried out
  using single node explants. Subculture was
  repeated until the required number of plantlets
  for each cultivar was achieved to conduct the
  experiment.
• At least 200 plantlets (12-15 cm long, each with
  4-5 leaves and good root system) per cultivar
  were transferred to the greenhouse of the
  Agricultural Research and Experiment Station at
  Dirab, near Riyadh, Saudi Arabia.

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Plate 2. Potato sprout which is used as starting
material for clonal propagation.
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Plate 3. Potato plantlet inside a test tube.
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Plate 4. Potato plantlet is being cut into
different stem cuttings with single node.
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Plate 5. Potato plantlet is being cut into
different stem cuttings with single node.
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Materials and Methods

• Plantlets of 6-8cm in length and with 4-6
  leaflets were transplanted into 25 cm pots. Pots
  were filled with 1 2 peat moss sand
• Acclimatization was carried out by applying mist
  system under plastic cover at about 10 minutes
  interval for 1 minute and gradually increasing
  time intervals until the end of second week when
  cover was removed.
• Temperature and relative humidity were set at 24
  2 C and 70 5, respectively.

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Materials and Methods

• Following two weeks of acclimatization, a class A
  evapotranspiration pan was placed in a central
  location between plants. Irrigation treatments
  were 20, 40, 60, 80 and 100 of water depletion
  by evaporation (WDE). Irrigation water was
  added near the plant base every other day.
• For every cultivar, eighty pots were used
  (representing five irrigation treatments x 4 pots
  x 4 replication per treatments).
• The experiment was designed as split plot with
  four replicates each. The cultivars were
  assigned as main plot and irrigation treatments
  as sub plots.

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Materials and Methods

• The first plant sample was taken at transplanting
  time. Destructive harvests consisting of one
  plant per subplot were randomly carried out 30,
  60 and 90 days after treatment (DAT).
• Drought tolerance was evaluated based on response
  of vegetative growth traits (plant height,
  number of branches, leaf area) as well as tuber
  traits (number and weight). Proline content in
  the leaves was also evaluated.
• Data were analyzed using statistical SAS program.
  Mean separation was carried out by the least
  significant difference.

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Results and Discussion

• Plant Height
• Number of Branches
• Leaf Area
• Proline content
• Tuber number
• Tuber weight

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Table 1 Comparison of plant height between
potato cultivars originated from micropropagated
plantlets, grown in the greenhouse and exposed to
irrigation treatments.
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Fig. 1 Effect of irrigation treatment on plant
height of potato cultivars originated from
micropropagated plantlets and grown in the
greenhouse.
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Table 2 Comparison of number of branches between
potato cultivars originated from micropropagated
plantlets, grown in the greenhouse and exposed
to irrigation treatments.
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Fig. 2 Effect of irrigation treatment on number
of branches/plant of potato cultivars originated
from micropropagated plantlets and grown in the
greenhouse.
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Table 3 Comparison of leaf area between potato
cultivars originated from micropropagated
plantlets, grown in the greenhouse and exposed to
irrigation treatments.
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Fig. 3 Effect of irrigation treatment on leaf
area of potato cultivars originated from
micropropagated plantlets and grown in the
greenhouse.
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Table 4 Comparison of proline content between
potato cultivars originated from micropropagated
plantlets, grown in the greenhouse and exposed to
irrigation treatments.
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Fig. 4 Effect of irrigation treatment on proline
content of potato cultivars originated from
micropropagated plantlets and grown in the
greenhouse.
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Table 5 Comparison of tuber number between
potato cultivars originated from micropropagated
plantlets, grown in the greenhouse and exposed to
irrigation treatments.
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Fig. 5 Effect of irrigation treatment on tuber
number of potato cultivars originated from
micropropagated plantlets and grown in the
greenhouse.
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Table 6 Comparison of tuber weight between
potato cultivars originated from micropropagated
plantlets, grown in the greenhouse and exposed to
irrigation treatments.
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Fig. 6 Effect of irrigation treatment on tuber
weight of potato cultivars originated from
micropropagated plantlets and grown in the
greenhouse.
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Conclusion

• Significant differences have been reported among
  cultivars and between irrigation treatments in
  most traits.
• In general, as water stress increased, vegetative
  growth and tuber yield decreased.
• Proline content increased as water stress
  increased.

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Conclusion

• Significantly higher tuber weight was measured in
  Rosetta plants at 60 DAT. Whereas after 90 DAT,
  both Rosetta and Sandy plants had higher tuber
  weight followed by Hermis, Safrina Asterix and
  Mondial plants, respectively.
• Accordingly three cultivars have been selected
  based on their tuber weight response at the 20
  WDE. These cultivars were
• Rosetta (drought tolerant),
• sandy ( moderately drought tolerance ) and
• Asterix ( drought sensitive ).

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Acknowledgment

• Authors wish to thank King Abdulaziz City for
  Science and Technology for providing financial
  support through Graduate Student funding program
  (No. GR-10-24). Thanks are also due to Research
  Center of the College of Food and Agricultural
  Sciences.

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Thank you for your Attention