Wetland Conservation

[pib] Species in news: Avicennia Marina


From UPSC perspective, the following things are important :

Prelims level : Avicennia marina

Mains level : Mangroves and their significance

Scientists at the Department of Biotechnology (DBT) have reported for the first time a reference-grade whole genome sequence of a highly salt-tolerant and salt-secreting true-mangrove species Avicennia Marina.

Avicennia marina

  • Avicennia marina is one of the most prominent mangroves species found in all mangrove formations in India.
  • It is a salt-secreting and extraordinarily salt-tolerant mangrove species that grows optimally in 75% seawater and tolerates >250% seawater.
  • It is among the rare plant species, which can excrete 40% of the salt through the salt glands in the leaves, besides its extraordinary capacity to exclude salt entry to the roots.

Why in news?

  • The A. marina genome assembled in this study is nearly complete and can be considered as a reference-grade genome reported so far for any mangrove species globally and the first report from India.
  • This study assumes significance as agriculture productivity globally is affected due to abiotic stress factors such as limited water availability and salinization of soil and water.

Its significance

  • Availability of water is a significant challenge to crop production in dryland areas, accounting for ~40 per cent of the world’s total land area.
  • Salinity is prevalent in ~900 million hectares globally (with an estimated 6.73 million ha in India), and it is estimated to cause an annual loss of 27 billion USD.
  • The genomic resources generated in the study will pave the way for researchers to study the potential of the identified genes for developing drought and salinity tolerant varieties of important crop species.
  • This is particularly important for the coastal region as India has 7,500m of coastline and two major island systems.

Try these PYQs:

Q.Which one of the following is the correct sequence of ecosystems in the order of decreasing productivity? (CSP 2013)

(a) Oceans, lakes, grasslands, mangroves

(b) Mangroves, oceans, grasslands, lakes

(c) Mangroves, grasslands, lakes, oceans

(d) Oceans, mangroves, lakes, grasslands


Q.The 2004 Tsunami made people realize that mangroves can serve as a reliable safety hedge against coastal calamities. How do mangroves function as a safety hedge? (CSP 2011)

(a) The mangrove swamps separate the human settlements from the sea by a wide zone in which people neither live nor venture out

(b) The mangroves provide both food and medicines which people are in need of after any natural disaster

(c) The mangrove trees are tall with dense canopies and serve as an excellent shelter during a cyclone or tsunami

(d) The mangrove trees do not get uprooted by storms and tides because of their extensive roots.

Back2Basics: Mangroves

  • A mangrove is a shrub or small tree that grows in coastal saline or brackish water.
  • Mangroves occur worldwide in the tropics and subtropics, mainly between latitudes 30° N and 30° S, with the greatest mangrove area within 5° of the equator.
  • Mangroves are salt-tolerant trees, also called halophytes, and are adapted to live in harsh coastal conditions.
  • They contain a complex salt filtration system and complex root system to cope with salt water immersion and wave action.
  • They are adapted to the low-oxygen conditions of waterlogged mud.
  • They are a unique group of species found in marshy intertidal estuarine regions and survive a high degree of salinity through several adaptive mechanisms.
  • They form a link between marine and terrestrial ecosystems, protect shorelines, provide habitat for a diverse array of terrestrial organisms.
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3 months ago

1.c, 2.d