Pak. J. Bot., 53(3): 991-999, 2021. DOI: http://dx.doi.org/10.30848/PJB2021-3(3) COMPARATIVE STUDY OF GROWTH AND BIOCHEMICAL ATTRIBUTES OF AVICENNIA MARINA (FORSSK.) VIERH OF INDUS DELTA AND IN VITRO RAISED PLANTS ABDUL MAJEED MANGRIO 1 , MUHAMMAD RAFIQ 2,3* , ZHANWU SHENG 3 , NADIR ALI RIND 2 , MAI FARZANA BIBI KOREJO 1 , SYED HABIB AHMED NAQVI 2 AND SHER MUHAMMAD MANGRIO 1 1 Institute of Plant Sciences, University of Sindh, Jamshoro, Pakistan 2 Institute of Biotechnology and Genetic Engineering, University of Sindh, Jamshoro, Pakistan 3 Haikou Experimental Station, Chinese Academy of Tropical Agricultural Sciences, Haikou 570101, China * Corresponding author’s e. mail: m.rafiq@usindh.edu.pk Abstract The study was conducted to optimize medium and growth conditions for micropropagation and field establishment of grey mangrove, Avicennia marina (Forssk.) Vierh using nodular stem sections as explants. Varying concentrations of 6- benzylaminopurine (BAP), kinetin (Kin) and indole-3-acetic acid (IAA) were supplemented in medium to assess their effects on the development of microshoots while indole-3-butyric acid (IBA), 1-naphthalene acetic acid (NAA) and indole-3-acetic acid (IAA) were supplemented to assess their role in root formation. All the treatments promoted shoot formation, the highest percentage of explants (86%) formed microshoots from the axillary buds with the highest number of microshoots per explant (2.40.1) were noted on MS medium consisting of 0.5mg/L of BAP, 1.0mg/L of Kin and 0.25mg/L IAA. In contrast 1.0mg/L IBA containing medium caused root formation in the maximum microshoots (82%) with 2.160.05 roots per microshoot, 27.50.5mm average root length. Furthermore, 65% of micropropagated A. marina plants were successfully survived for two years during 2015-17 in region II (Jamshoro). These plants showed better growth as plant height, numbers of leaves, chlorophyll contents, sugars and proteins were increased comparing with same age plants of region I. On the other hand, an increase in stem diameter, number of branches, and the amount of total phenolic contents, total flavonoids and antioxidants was found in plants of region I (Shah Bander, Indus Delta). In conclusion, micropropagated plantlets of A. marina were successfully established in geographically hot region which will support to establish mangrove plants around the banks of Indus River. Key words: Avicennia marina, Micropropagation, Chlorophyll contents, Carbohydrates, Proteins, Phenolic acids. Introduction Mangroves are a diverse group of plants found in the coastlines of tropical and subtropical intertidal zones of 118 countries and territories. Mangroves cover an area of above 18 million hectares of the globe representing 42% in Asia and about 7% in South Asia (Giri et al., 2015). Pakistan ranked to have 24 th largest mangrove forest and 95% of mangroves forests are found in the marshes of Indus Delta of Sindh province along the coastlines of Arabian Sea (Giri et al., 2015). A. marinais the predominant mangrove species of Indus Delta covering about 97% of mangrove forests together with Aegicerias corniculata, Ceriops tagal and Rhizophore mucronata (Aziz & Khan, 2000; Giri et al., 2015). The existence of these mangrove forests are permanently dependant on supply of fresh water and residues from River Indus that flows through Indus Delta to Arabian Sea. A. marina of family ‘Avicenniaceae’ is a mangrove tree that can attain above ten meters height (Giesen et al., 2007). A. marina is a multi-use tree but in Pakistan its utilization is restricted to few types such as wood and fodder by coastal populations (Spalding et al., 1997; Tariq et al., 2006). A. marina plant is rich source of alkaloids, steroids, triterpenes, saponins, flavonoids and tannins that possess pharmacological, toxicological, and ecological importance (Molaeea et al., 2017). The aerial parts of A. marina possess antiviral, antiparasitic, antifungal, antibacterial, anti-cancer anti-ulcer activities (Bandaranayake, 2002; Khafagi et al., 2003; Arivuselvan et al., 2011; Iranawati et al., 2018; Yang et al., 2018). Mangrove habitat is severely destructed due to land reclamation and industrial effluents (Kathiresan & Bingham, 2001) with estimated global mangrove loss of about one million hectares each year (Mohamed, 1996). The Indus Delta is one of the most threatened among large deltas due to utilization of upstream freshwater for agriculture. The sever reduction in upstream flow of fresh water increased the concerns about conservation of diversity in mangrove habitat. There is an urgent need of mangrove afforestation program for conservation of habitat and to increase the productivity of intertidal zones of the coast, the deltas and banks of major rivers systems. Mangrove species are mostly regenerated through seeds but there are problems of collection of propagules from natural environment, post dispersal predation of seed by crab, short life of seed viability and seed storage as most seeds are of large size (Robertson et al., 1990; Saenger & Siddiqi, 1993). Due to dynamic nature of mangrove habitat, the survival of seedlings in the potential areas is also poor (Saenger & Siddiqi, 1993). There is a necessity of an alternative to seed regeneration as large scale In vitro propagation for prepetuation of mangrove species and their reestablishment in the field (Hartmann & Kester, 1989). Mangrove tissue culture and In vitro micropropagation technology can be used as an alternative for the conservation of unique genotypes for commercial purpose. Tissue culture of mangroves is difficult because of explants which turn brown and die after In vitro culturing (Kathiresan & Bingham, 2001). Only few mangrove species have been micropropagated successfully such as Excoecaria agallocha, Avicennia officinalis and Avicennia marina (Al-Bahrany & Al- Khayri, 2003: Arumugam & Panneerselvam, 2012).