Investigation of Growth Regulators Profile in Reproductive Organs of Tissue Culture-Derived and Offshoot-Derived ‘Barhee’ Date Palm

Document Type : Full Paper

Authors

1 Date Palm and Tropical Fruit Research Center, Horticultural Science Research Institute, Agricultural Research Education and Extension Organization, Ahwaz, Iran

2 Date Palm and Tropical Fruits Research Center, Horticultural Sciences Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Ahwaz, Iran

3 Date Palm and Tropical Fruit Research Center, Horticultural Science Research Institute, Agricultural Research Education and Extension Organization, Ahwaz, Iran.

Abstract

This study was conducted in order to investigate the changes in the growth regulators related to fruit setting in the pollination season on both tissue culture-derived and offshoot-derived date palms cv. Barhee (10 years old) in the Date Palm and Tropical Fruit Research Center of Ahvaz city. At the beginning of spring, palm trees were selected from each group of tissue culture and offshoot trees and sampling of flowers and fruits was done in the three stages including: spath appearance, ripe spath and 2 weeks after pollination in three replications. In order to evaluate fruit setting, three spathes in each palm (1-2 days before natural opening) were pollinated with Ghanami cultivar pollen by traditional method. The plant hormones including auxin (IAA and IBA), gibberellin (GA1, GA3, GA4, GA9), cytokinin (Zeatin and Kinetin), abscisic acid and jasmonic acid were measured in the flower or fruit samples collected from tissue culture and offshoot trees. Five weeks after pollination, fruit set percentage, parthenocarpic fruits percentage and flower and fruit drop percentage were recorded. The results showed that tissue culture derived plants had less fruit set percentage and more seedless fruit and fruit drop percentages compared to off shoot derived plants. Also, the fruit yield in the tissue culture plants was lower than off shoot derived plants.  The levels of gibberellin, auxin, and cytokinin hormones in the off shoot derived plants were higher than tissue culture plants in most of the measured stages.  The tissue culture plants had a higher amount of abscisic acid and jasmonic acid than offshoot plants. By using multiple linear regression analysis and superior model selection, the amount of abscisic acid and jasmonic acid of flower and fruit had a negative relationship with the amount of fruit set. The fruit setting was positively correlated with the amount of kinetin, indole acetic acid, GA3, GA4 and GA9 of flowers and fruits, while had a negative correlation with the amount of abscisic acid and jasmonic acid.

Keywords

Main Subjects


Extended Abstract

Introduction

Date palm (Phoenix dactylifera L.) is an important fruit crop in arid and semi-arid regions of the world. Today, the development of tissue culture propagation methods has enabled date palm to be rapidly propagated on a large scale. One of the main weaknesses of this method is the possibility of the appearance of abnormal phenotypes such as delayed flowering, low levels of fruiting and the formation of parthenocarpic fruits. There is a difference in the amount of abnormalities among date palm cultivars. The low levels of natural fruiting due to the high production of parthenocarpic fruits or high fruit drop in some cultivars of tissue culture date palm compared to the trees obtained from offshoot date palm, especially in the Barhee cultivar, leads to inappropriate yields and economic losses to gardeners. Growth regulators play an important role in fruit formation during the stages of flowering, pollination and fertilization. Therefore, this study was conducted to compare the hormonal levels of the flowers and fruits in date trees derived from tissue culture and offshoot and their relationship with the amount of fruiting in two groups of trees.

 

Materials and Methods

This study was conducted in order to investigate the changes in the growth regulators related to fruit setting in the pollination season on both tissue culture-derived and offshoot-derived date palms cv. Barhee, in ate Palm and Tropical Fruit Research Center of Ahvaz city. At the beginning of spring, palm trees were selected from each group of tissue culture and offshoot trees and sampling of flowers and fruits was done in the three stages including spath appearance, ripe spath and 2 weeks after pollination in three replications. In the pollination stage, three spathes in each palm (1-2 days before natural opening) were pollinated with Ghanami cultivar pollen. The plant hormones: auxin (IAA and IBA), gibberellin (GA1, GA3, GA4, GA9), cytokinin (Zeatin and Kinetin), abscisic acid and jasmonic acid were measured in the flower or fruit samples collected from tissue culture and offshoot trees. Five weeks after pollination, fruit set percentage, parthenocarpic fruits percentage and flower and fruit drop percentage were recorded.

 

Results and Discussion

The results showed that tissue culture derived plants had less fruit set percentage and more parthenocarpic fruits and fruit drop percentages as compared to off shoot derived plants. Also, the fruit yield in the tissue culture derived plants was lower than off shoot derived plants.  The levels of gibberellin, auxin, and cytokinin hormones in the off shoot derived plants were higher than tissue culture plants in most of the measured stages. The tissue culture plants had a higher amount of abscisic acid and jasmonic acid than offshoot plants. By using multiple linear regression analysis and superior model selection, the amount of abscisic acid and jasmonic acid of flower and fruit had a negative relationship with the amount of fruit set. The fruit setting was positively correlated with the amount of kinetin, indole acetic acid, GA3, GA4 and GA9 of flowers and fruits, while had a negative correlation with the amount of abscisic acid and jasmonic acid . Therefore, higher parthenocarpic percentage in tissue culture-derived date palms compared to offshoot-derived date may be due to the difference in hormone levels or different ratios of hormones in them. The failure of normal fruiting in the tissue culture derived plants was probably due to many interrelated events that lead to a slow growth of pollen tube at early stages of fruit growth and which may possibly be accentuated by the relatively high ABA contents during this period.

 

Conclusion

According to the results of this research, one of the causes of unfavorable fruiting in tissue culture-derived date palms is the change in the internal hormone profile of the flowers and fruits compared to the offshoot-derived trees. Changes in the levels of internal hormones accompany with a decrease in the growth of the pollen tube lead to lack of fertilization or incomplete fertilization and as a result, the formation of parthenocarpic fruits and finally, a decrease in fruiting and fruit growth.

کاوند، عبدالرضا. 1395. مطالعه جنبه ­های آناتومیکی و مولکولی عدم باروری احتمالی نخل­ های خرمای حاصل از کشت­بافت رقم برحی از سنین باردهی متفاوت در استان خوزستان. گزارش نهایی پروژه تحقیقاتی. مؤسسه تحقیقات ثبت و گواهی بذر و نهال، کرج، 64 صفحه.
مرعشی، سید سمیح. 1385. بررسی سازگاری و تعیین خواص کمی و کیفی میوه ارقام خرما در منطقه طبس. گزارش نهایی پروژه تحقیقاتی. موسسه تحقیقات خرما و میوه‌های گرمسیری کشور. اهواز، 133 صفحه.
 
REFERENCES
Abahmane, L. (2011). Date palm micropropagation via organogenesis. In Jain, S. M., Al-Khayri, J. M., Johnson, D.V (Eds). Date palm biotechnology, (pp. 69-90). Springer, Dordrecht. https://doi.org/ 10.1007/978-94-007-1318-5_5.
 
Abou-Aziz, A. B., Maxiuous, S. S., Desouky, I. A., & Samara. N. R. E. (1982, March). Effects of GA3 and hand pollination on the yield and quality of Sewy dates. Proceeding of The First Symposium on The Date Palm. (pp. 258-268). King Faisal University, Al-Hassa, Saudi Arabia.
 
Ali-Dinar, H. M., & Alkhateeb, A. A. (2005, May). Barhee fruit setting problems at Kingdom of Saudi Arabia: Research approaches to understand the physiological and physical events of the phenomenon. Proceeding the International Workshop on True-to-Types of Date Palm Tissue culture-derived Plants; Morocco, 121-127.
 
Al-Khayri, J. M. (2001). Optimization of biotin and thiamine requirements for somatic embryogenesis of date palm (Phoenix dactylifera L.). In Vitro Cellular & Developmental Biology, 37, 453-456. https://doi.org/10.1007/s11627-001-0079-x.
 
Bouhouche, N., Al-Mazroui, H. S., & Zaid, A. (2007). Fertilization Failure and Abnormal Fruit Set in Tissue Culture-Derived Date Palm (Phoenix dactylifera L.). III International Date Palm Conference, ISHS. Acta Horticulturae, 736, 225-232. https://doi.org/10.17660/ActaHortic.2007.736.20.
Cohen, Y., Korchinsky, R., & Tripler, E. (2004). Flower abnormalities cause abnormal fruit setting in tissue culture-propagated date palm (Phoenix dactylifera L.). The Journal of Horticultural Science and Biotechnology, 79, 1007-1013. https://doi.org/10.1080/14620316.2004.11511853.
 
Dobrev, P., & Kamínek, M. (2002). Fast and efficient separation of cytokinins from auxin and abscisic acid and their purification using mixed-mode solid-phase extraction. Journal of Chromatography A, 950(1), 21-29. https://doi.org/ 10.1016/S0021-9673(02)00024-9.
 
Dorcey, E., Urbez, C., Blazquez, M. A., Carbonell, J., & Perez-Amador, A. (2009). Fertilization-dependent auxin response in ovules triggers fruit development through modulation of gibberellin metabolism in ArabidopsisPlant Journal, 58, 318-332. https://doi.org/ 10.1104/pp.110.160044.
 
Ge, L., Peh, C. Y. C., Yong, J. W. H., Tan, S. N, Hua, L., & Ong, E. S. (2007). Analyses of gibberellins by capillary electrophoresis–mass spectrometry combined with solid-phase extraction. Journal of Chromatography A, 1159 (1), 242–249. https://doi.org/10.1016/j.chroma.2007.05.041.
 
Gorguet, B., Van-Heusden, A. W., & Lindehout, P. (2005). Parthenocarpic fruit development in tomato. Plant Biology, 7, 131-139. https://doi.org/10.1055/s-2005-837494
Hadi, S., Al-Khalifah, N. S., & Moslem, M. A. (2015). Hormonal basis of ‘Shees’ fruit abnormality in tissue culture derived plants of date palm. International Journal of Agriculture and Biology, 17(3), 607-612. https://doi.org/ 10.17957/IJAB/17.3.14.088.
 
Jain, S. M. (2012). Date palm biotechnology: Current status and prospective-an overview. Emirates Journal of Food and Agriculture, 24, 386-399.
Kavand, A. R. (2016). Study of the anatomical and molecular aspects of probable fruitlessness of date palms derived from tissue culture of Berhi cultivar in Khuzestan. Final report of project, Seed and Plant Certification Research Institute, Karaj, 64 pp. (In Persian).
Liu, X., Liao, M., Deng, G., Chen, S., Ren, Y., & Liu, W. (2008). Changes in endogenous hormone and polyamines of fruits during growth and development of pear fruit. World Journal of Agricultural Sciences, 4, 40-47. https://doi.org/ 10.17660/eJHS.2020/85.4.6.
Mater, A. M. (1991). Date palm culture and its product. Al-Hikma Press, University of Basrah, Iraq. 420 pp.
Marashi, S. S. (2007). Study on the adaptability and determination of quantitative and qualitative fruit characteristics of date cultivars in Tabas region. Final Report of Project, Date palm and tropical fruits research institute. (In Persian).
Mohamad Attaha, A. H., &  Malik Al-Saadi, S. A. A. (2015).  Anatomical and hormonal studies of floral and fruiting behavior of phoenix dactylifera cv. Barhee. International Journal of Current Advanced Research, 4(12), 531-536.
Pandolfini, T. (2009). Seedless fruit production by hormonal regulation of fruit set. Nutrients, 1, 168-177. https://doi.org/ 10.3390/nu1020168.
 
Pharis, R. P., & King, R. (1985). Gibberellins and reproductive development in seed plants. Annual Review of Plant Physiology, 36, 517-568. https://doi.org/10.1146/annurev.pp.36.060185.002505.
Reuveni, O. 1986. Dates. In Monselise, S. P. (ed.), CRC Handbook of Fruit Set and Development. CRC Press, Florida, USA. 119-144
Setha, S., S. Kondo, Hirai, N., & Ohigashi, H. (2004). Xanthoxin, abscisic acid and its metabolite levels associated with apple fruit development. Plant Science, 166, 493-499. https://doi.org/10.1016/j.plantsci.2003.10.020.
Shabana, H. R., Zaid, A. W., &  Al- Sanbul, A. K. I. (2006). Date fruits, physiology, harvest, handling and post-harvest caring. FAO, Rome, Italy. 132 pp.
Talon, M., Hadden, P., & Primo-Millo, E. (1990). Gibberellins in Citrus sinensis: a comparison between seeded and seedless varieties. Journal of Plant Growth Regulation, 9, 201-206. https://doi.org/10.1007/BF02041963.
Talon, M., Zacarias, L., & Primo-Millo, E. (1992). Gibberellins and parthenocarpic ability in developing ovaries of seedless mandarins. Plant Physiology, 99, 1575-1581. https://doi.org/10.1104/pp.99.4.1575.