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

Carditis, It has been shown by prospective studies that Rheumatic heart dis...

It has been shown by prospective studies that Rheumatic heart disease (RHD) is linked to the occurrence of carditis during the first episode of ARF. If the first episode is accompa

Show some fungal diseases transmitted by animal feces, Q. What are some fun...

Q. What are some fungal diseases transmitted by animal feces? Pigeon and Bat feces can carry Histoplasma capsulatum, the fungus agent of histoplasmosis. The infection is transm

Explain balloon pulmonary valvuloplasty, Pulmonary stenosis is a relatively...

Pulmonary stenosis is a relatively common congenital heart defect. Usually these children with mild to moderate pulmonary stenosis survive into childhood. Since bicuspid pulmonary

What event marks the beginning of the menstrual cycle, What event marks the...

What event marks the beginning of the menstrual cycle? What is the blood concentration of FSH, LH, estrogen and progesterone in this phase of the cycle? By convention the menst

Defective extra-preputial protrusion of the penis, Defective extra-preputia...

Defective extra-preputial protrusion of the penis This defect is a result of hypoplasia or a defective penile erection due to a congenital mucosal fold – the frenulum - betwee

Direction of energy flow, Direction of Energy Flow Now let us consider...

Direction of Energy Flow Now let us consider the first point that is the direction of flow of energy. Energy flows from lower (producer) to higher (herbivore, carnivore, etc.)

Homework, why do ecological models commonly have limited applications?

why do ecological models commonly have limited applications?

Planning the nursing care for infective endocarditis, Planning the Nursing ...

Planning the Nursing Care   Provide bed rest  Administer antibiotics as advised Prevent infection  Implementation of Nursing Care  Provide Bed Rest   Sin

Ms j, what direct or indirect effect is " acid rain" thought to have on (I)...

what direct or indirect effect is " acid rain" thought to have on (I) lakes, (ii) forests and (iii) buildings

What is dichogamy, What is dichogamy? Dichogamy is the phenomenon of th...

What is dichogamy? Dichogamy is the phenomenon of the maturation of female reproductive structures of the plant in a dissimilar period to the maturation of the male reproductiv

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