Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

A. Mustard - white rust
White rust caused by Albugo cruciferarum (Gray) is the most serious disease in rapeseed and mustard and is responsible for considerable yield losses.
B. Paddy - brown spot
Brown spot is a fungal disease that infects the coleoptile, leaves, leaf sheath, panicle branches, glumes, and spikelets of rice (paddy).
C. Wheat - red rust
Stem rust, also known as cereal rust, black rust, red rust or red dust is caused by the fungus Puccinia graminis, which causes significant disease in cereal crops.
D. Sugarcane - red rot
Sugarcane (Saccharum spp.) is a commercially important crop, vulnerable to the fungal disease red rot caused by Colletotrichum falcatum. The pathogen attacks sucrose accumulating parenchyma cells of the cane stalk.

Main substance involved in transfer of electrons in photosynthesis is Cytochrome.
In photosynthesis, the cytochrome complex functions to mediate the transfer of electrons and energy between the two photosynthetic reaction center complexes, Photosystem II and Photosystem I, while transferring protons from the chloroplast stroma across the thylakoid membrane into the lumen.
Cytochrome c4 functions as a physiological electron carrier in the photosynthetic electron transport chain in R. gelatinosus.

Burgundy mixture contains sodium carbonate in place of CaCO₃ as in Bordeaux mixture was discovered in 1887.
Bordeaux mixture contains copper(II) sulfate, CuSO₄, and hydrated lime, Ca(OH)₂, while Burgundy mixture contains copper sulphate, CuSO₄, and sodium carbonate, Na₂CO₃.
Burgundy mixture, named after the French district where it was first used to treat grapes and vines, is a mixture of copper sulfate and sodium carbonate. This mixture, which can have an overall copper concentration within the range of 1% to 20%, is used as a fungicidal spray for trees and small fruits.

Quantasomes occur on the surface of Plasmalemma.
Quantasomes were first identified by Roderic B. Park in 1962.
Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place. They are embedded in a paracrystalline array on the surface of thylakoid discs in chloroplasts.
They are composed of lipids and proteins that include various photosynthetic pigments and redox carriers.

The causal agent of Ring spot of potato is Clavibacter michiganensis.
Ring spot causes vascular wilt in the above ground parts of the potato plant, with discolouration and loss of texture/consistency noted in infected tubers.
It leads to Losses of up to 50% of the crop have been noted in severe infections.

Nitrogen loss from urea application in paddy fields is known as Denitrification.
Denitrification in paddy soils is an environmentally important reaction, which reduces leaching or emission of nitrogen pollutants.
It is the process that converts nitrate to nitrogen gas, thus removing bioavailable nitrogen and returning it to the atmosphere.

Pinwheel inclusion bodies are Potyvirus.
A unique feature shared by all plant viruses of the Potyviridae family is the induction of characteristic pinwheel-shaped inclusion bodies in the cytoplasm of infected cells.
These cylindrical inclusions are composed of the viral-encoded cylindrical inclusion helicase (CI protein).

A sudden change from anaerobic to an aerobic process produces Pasteur Effect.
The Pasteur effect describes how available oxygen inhibits ethanol fermentation, driving yeast to switch toward aerobic respiration for increased generation of the energy carrier adenosine triphosphate (ATP).
The effect was described by Louis Pasteur in 1857 in experiments showing that aeration of yeasted broth causes cell growth to increase while the fermentation rate decreases, based on lowered ethanol production.

Blossom end rot disorder in tomato is caused by the deficiency of Ca.
Blossom end rot is caused by a localized calcium deficiency in the distal end of the fruit.
Calcium is a relatively immobile element; calcium uptake is therefore heavily influenced by anything that affects water uptake by a plant.
It is required in relatively large quantities by rapidly growing fruit, especially by those cells at the blossom end of the young fruit.

The effective control of flag smut of wheat (Urocystis tritici) can be done by adopting of Use of resistant varieties, Seed treatment, and Crop rotation.
Strategies to prevent flag smut include the use of disease-resistant cultivars, chemical seed treatments, and crop rotation to reduce the amount of inocula present.
The spores germinate in dry soils, and maintaining wetter soils helps to diminish their viability. Carboxin is a commonly used fungicide on seeds, which works well to prevent onset of disease.
Application of systemic fungicides early in the growing season and at low doses is effective at controlling the disease.