Plant Pathology Short Question 1

Q. 1. What is facultative parasite?

Ans. When fungi pass their mode of life as saprophyte in the beginning and later or under certain condition, becomes parasite causing a disease they are known as facultative parasite.

Q. 2. What is macrocyclic rust?

Ans. Macrocyclic is long-cycled life cycle in this case at least one or more than one type of binucleate spores in addition to telutospores are produced in a complete life cycle.

Q. 3. What is mycorrhiza?

Ans. Sometimes fungi also live in close association with the roots of gymnosperms

and angiosperms; this association between fungal hyphae and roots of higher plants is known as mycorrhiza.

Q. 4. What is hypertrophy?

Ans. The most apparent effect is some disease is the over-growth of one or more plant organs or some parts of them and when this phenomenon occurs due to increase of cell size it is called hypertrophy.

Q. 5. What is ectoparasite? Give an example.

Ans. When parasitic fungi grow superficially on the surface of the host plant without penetrating the deeper host tissue it known as ectoparasite.

Q. 6. What is inoculum?

Ans. The portion of the individual pathogen which are brought into contact with the host plant is called inoculum.

Q.7. Distinguish between pathogen and parasite.

Ans.

Pathogen is an agent that by its persistent

association causes the disease. It may be living or non-living

Parasite absorbs nutrition from the host

and ultimately kills them.It is generally living

Q. 8. What are systemic fungicides?

Ans. Systemic fungicides are those which are fungicidal after absorption and subsequent translocation and are able to control the growth of pathogen in the host tissue.

Q. 9. What are phytoalexin?

Ans. Phenolic substances which do not exist in the host tissue but are formed as a result of host-pathogen interaction are known as phytoalexin.

10.What do you mean by wild fire toxin?

Wild fire toxin, produced by Pseudomonas tabaci, is monotropic, as are many of the toxins produced by bacteria which attack animals. This is an unstable toxin. 

Q. 11.Name the toxin which produces HV toxin.

Ans. Helminthosporium victoriae.

Q. 12.What is aflatoxin?

Ans. It is a type of mycotoxin produced by fungi in fruits, vegetables, foodgrains, seeds, ligume etc. Mainly it is produced from Aspergillus flavus.

Q. 13. Define pathotoxin. Give an example.

Ans. A few toxins are species-specific. They only affect plants susceptible to the pathogen i.e. host-specific toxins are called pathotoxin. E.g. Fusaric acid.

Q. 14. Define biopesticides.

Ans. The pesticides which are derived from biological origin.

(i) Nabam (ii) Zinab (iii) Ferbam etc.

Q. 15. What do you mean by necrotic symptoms?

Ans. These symptoms are evidence of death of the affected tissue caused by both parasitic and non-parasitic causal agents.

Q. 16. Name the bacterial phytopathogen.

Ans. Xanthomonas oryzae cause bacterial blight.

Q. 17. Name one microcyclic heteroceous rust.

Ans. Puccinia graminis.

Q. 18. Name three commonly used sulpher fungicides?

Naam, Zinab, Ferbam