Plant Pathology - Study Mode

[#236] The perfect stage of Colletotrichum falcatum (causes red rot of sugarcane) is
Correct Answer

(A) Glomerella tucumanensis

Explanation

Solution: The perfect stage of Colletotrichum falcatum (causes red rot of sugarcane) is Glomerella tucumanensis. Sugarcane (Saccharum spp.) is a commercially important crop, vulnerable to fungal disease red rot caused by Colletotrichum falcatum. The pathogen attacks sucrose accumulating parenchyma cells of cane stalk leading to severe losses in cane yield and sugar recovery.

[#237] Who gave the biochemical basis of Gene for Gene hypothesis?
Correct Answer

(A) Vanderplank

Explanation

Solution: Vanderplank gave the biochemical basis of Gene for Gene hypothesis. The gene for gene hypothesis states that for each gene controlling resistance in the host, there is corresponding gene controlling pathogenicity in the pathogen. The resistance of the host is governed by dominant genes and virulence of pathogen is by recessive genes.

[#238] Which is the role of molybdenum?
Correct Answer

(D) Nitrogen fixation

Explanation

Solution: Nitrogen fixation is the role of molybdenum. The molybdenum nitrogenase is responsible for most biological nitrogen fixation, a prokaryotic metabolic process that determines the global biogeochemical cycles of nitrogen and carbon. Molybdenum is utilized by selected enzymes to carry out redox reactions. Enzymes that require molybdenum for activity include nitrate reductase, xanthine dehydrogenase, aldehyde oxidase and sulphite oxidase.

[#239] Rust of linseed and flax (autoecious rust) is caused by
Correct Answer

(D) Melampsora lini

Explanation

Solution: Rust of linseed and flax (autoecious rust) is caused by Melampsora lini. The pathogen is an obligate biotroph meaning that each stage of its cycle is dependent on having a living host. The direction between reproducing sexually or asexually is dependent on the availability of a host. Sexually, the life cycle starts when basidiospores land on flax leaves and form pycnium during December and through January.

[#240] Victoria blight epidemic devastated which crop in 1946?
Correct Answer

(B) Oat

Explanation

Solution: Victoria blight epidemic devastated Oat crops in 1946. Cochliobolus victoriae is a fungal plant pathogen. It caused the disease called "victoria blight" affecting oats and similar grains. Symptoms include stem weakening, seedling death, leaf damage, and premature ripening of seeds. Victorian oat varieties have resistance to crown rust, which is considered one of the most important diseases in oats. In the 1940s, Victoria oats were very popular among American oat farmers because of this crown rust resistance.