Categories of gifted species, Biology

Assignment Help:

Categories of Gifted Species

This group of nitrogen fixers has been divided into three categories:

  1. Rhizobium which includes fast growing species,
  2. Bradyrhizobium which include slow growing strains and
  3. Azorhizobium which is a combination of traits from Rhizobium and Bradyrhizobium. Rhizobium is highly specific with respect to its host and that is why the nomenclature is based on the specific host which it infects.

For example the Rhizobium infecting clovers and peas are called trifolii and leguminosarum respectively. The genus Bradyrhizobium is not so rigid with regard to the host partners. All the strains of Rhizobium and Bradyrhizobium produce nodules on the host, but Azorhizobium produces nodules on the stem of Sesbania rostrata and Aeschynomene afraspera.

Parasponia is the only non-legume genus where the bacterial partner is Rhizobium. This observation has raised the hope of creating nitrogen fixing associations between Rhizobium and important crops like cereals. Nitrogen fixing nodules on the roots of woody plants like Alnus, Casuarino, Myria are formed by symbiotic association with Frankia a member of actinomycetes. Anabaena-Azolla association is experimentally shown to be a strong source of nitrogen fertiliser in wetland rice agriculture. Free-living heterocysts cyanobacteria are also known to contribute significant amount of nitrogen to the wetland rice ecosystem. Lichens are associations between fungi and N2-fixing cyanobacteria. They are very important source of N2 in barren harsh also known to occur in tropical plants like Psychotria partner.


Related Discussions:- Categories of gifted species

Protein synthesis with dna, Protein Synthesis with DNA The central dogm...

Protein Synthesis with DNA The central dogma of modern biochemistry is totally based on the coded information holded within deoxyribonucleic acid (DNA). Double stranded DNA is

What is the probability that their child have alkaptonuria, A recently marr...

A recently married man and woman discover that each had an uncle with alkaptonuria, otherwise known as "black urine disease," a rare disease caused by an auto somal recessive allel

What is oxytocin receptors, Which of the following serves as an actuating s...

Which of the following serves as an actuating signal, or as part of an actuating signal, in a positive feedback system? A. Blood plasma levels of PTH (Parathryroid Hormone).

Indications for surgery of mitral regurgitation, Q. Indications for Surgery...

Q. Indications for Surgery of mitral regurgitation? Surgery is indicated in all symptomatic patients (class II and above) with severe mitral regurgitation and normal or decreas

Why is it rare to find hemophilic women, Why is it rare to find hemophilic ...

Why is it rare to find hemophilic women? There are less hemophilic women than hemophilic men because women need to have two X chromosomes affected to develop the disease while

Nutrient elements of plants, Nutrient Elements of Plants Let us first ...

Nutrient Elements of Plants Let us first find out the chemical composition of plants and see which element nature has selected to support their healthy growth. Only then we wi

Composition of capillaries, Normal 0 false false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain the relative nucleotide content of each sample, Can you help explai...

Can you help explain this question in fairly simple terminology? A certain sample of DNA has a Tm of 65oC, while another has a Tm of 58oC. What can you tell about the relative n

Protein digestion, Protein Digestion Enzymes that digest proteins are ...

Protein Digestion Enzymes that digest proteins are divided into two groups endopeptidases and exopeptidases according to site of their action in the protein molecule. Endopept

What is classic blalock-taussig bt shunt in shunt operations, What is Class...

What is Classic Blalock-Taussig BT Shunt in Shunt Operations ? Subclavian artery, which arises from innominate artery, is anastomosed to pulmonary artery. In a patient with lef

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd