Publication Date:
2017
Short description:
Physiological Responses to Drought Stress in Jatropha curcas Seedlings / Contran, Nicla; Ledda, Luigi; Mulas, Maurizio; Cerana, Raffaella; Lubino, Marcello. - In: AMERICAN JOURNAL OF EXPERIMENTAL AGRICULTURE. - ISSN 2231-0606. - 16:(3)(2017), pp. 1-13. [10.9734/JEAI/2017/33639]
abstract:
Aims: The aim of the study was to investigate the physiological mechanisms of Jatropha curcas
seedlings exposed to drought and the possible influence of seedling age.
Study Design: A pot experiment was carried out using a completely randomized design with two
seedling ages (2- and 3-month-old seedlings), two treatments per age (Watered: fully irrigated, and
Unwatered: Not irrigated), six replicates (24 pots).
Place and Duration of Study: The experiment was performed in a greenhouse facility located at
the Experimental Station “Mauro Deidda” (Department of Agriculture of University of Sassari) at
Ottava (Sassari, Italy) between June and September 2011.Methodology: To investigate the responses of 2- and 3-month-old J. curcas seedlings exposed to
drought stress on 4th, 8th, 12th, 19th, and 26th day from treatment’s beginning, leaf and soil water
content, biometric, gas exchange, and chlorophyll a fluorescence measurements were performed;
on 26th day from treatment’s beginning, biometric destructive measurements were carried out.
Results: Results support the hypothesis that J. curcas is appropriate to be cultivated in areas with
limited water availability or prolonged periods of drought and highlight that mechanisms of drought
response are highly influenced by seedling age. J. curcas seedlings maintained a good leaf water
status by means of an effective stomatal closure, associated with a reduced aboveground growth
and an increased root:shoot ratio. Under drought stress, 2-month seedlings showed a higher
allocation of resources to roots compared to 3-month seedlings. Drought resulted in more
detrimental effects on the photosynthetic response of 3-month seedlings, inducing the reduction of
stomata conductance and the loss of photosystem II integrity. 2-month seedlings were instead able
to activate mechanisms of drought tolerance through the activation of excess energy dissipation
mechanisms.
Conclusion: In the early stage of crop establishment, the transplanting of J. curcas 2-month
seedlings proved to be more effective in order to avoid water stress related consequences.
seedlings exposed to drought and the possible influence of seedling age.
Study Design: A pot experiment was carried out using a completely randomized design with two
seedling ages (2- and 3-month-old seedlings), two treatments per age (Watered: fully irrigated, and
Unwatered: Not irrigated), six replicates (24 pots).
Place and Duration of Study: The experiment was performed in a greenhouse facility located at
the Experimental Station “Mauro Deidda” (Department of Agriculture of University of Sassari) at
Ottava (Sassari, Italy) between June and September 2011.Methodology: To investigate the responses of 2- and 3-month-old J. curcas seedlings exposed to
drought stress on 4th, 8th, 12th, 19th, and 26th day from treatment’s beginning, leaf and soil water
content, biometric, gas exchange, and chlorophyll a fluorescence measurements were performed;
on 26th day from treatment’s beginning, biometric destructive measurements were carried out.
Results: Results support the hypothesis that J. curcas is appropriate to be cultivated in areas with
limited water availability or prolonged periods of drought and highlight that mechanisms of drought
response are highly influenced by seedling age. J. curcas seedlings maintained a good leaf water
status by means of an effective stomatal closure, associated with a reduced aboveground growth
and an increased root:shoot ratio. Under drought stress, 2-month seedlings showed a higher
allocation of resources to roots compared to 3-month seedlings. Drought resulted in more
detrimental effects on the photosynthetic response of 3-month seedlings, inducing the reduction of
stomata conductance and the loss of photosystem II integrity. 2-month seedlings were instead able
to activate mechanisms of drought tolerance through the activation of excess energy dissipation
mechanisms.
Conclusion: In the early stage of crop establishment, the transplanting of J. curcas 2-month
seedlings proved to be more effective in order to avoid water stress related consequences.
Iris type:
1.1 Articolo in rivista
Keywords:
Chlorophyll a fluorescence; gas exchange; Physic nut; water relations; water stress
List of contributors:
Contran, Nicla; Ledda, Luigi; Mulas, Maurizio; Cerana, Raffaella; Lubino, Marcello
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