Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

M. W. Beijetnick is regarded as the Father of virology.
Martinus Willem Beijerinck was a Dutch microbiologist and botanist who was one of the founders of virology and environmental microbiology. He is credited with the discovery of viruses, which he called "contagium vivum fluidum".
In 1898, he published results on the filtration experiments demonstrating that tobacco mosaic disease is caused by an infectious agent smaller than a bacterium.

Saccharomyces can readily respire without oxygen.
Saccharomyces is a genus of fungi that includes many species of yeasts. They are unicellular and saprotrophic fungi.
Colonies of Saccharomyces grow rapidly and mature in three days. They are flat, smooth, moist, glistening or dull, and cream in colour.
It is widely used in making bread, wine, and beer, through the process of fermentation that does not require oxygen.

Transfer of T-DNA is the function of the Vir C gene of Agrobacterium tumefaciens.
Agrobacterium tumefaciens induces tumors in plants by transferring a piece of single-stranded DNA, T-DNA, from its tumor-inducing (Ti) plasmid into plant cells.
The subsequent integration and expression of T-DNA in the plant genome leads to the formation of crown gall tumors.
Vir genes are directly involved in T-DNA cleavage from the Ti plasmid, T-DNA processing, transferring and integration into plant nuclei.

Phosphorus is drilled in upland crops to Put it near roots.
Phosphorus is important in cell division and the development of new tissue. Adding phosphorus to soil low in available phosphorus promotes root growth and winter hardiness, stimulates tillering and often hastens maturity.

Three carbons of phosphoglyceric acid formed during carbon fixation are derived from RuBP + CO₂.
Phosphoglyceric acid (PGA), a 3-carbon organic acid formed during glycolysis is the first relatively stable compound formed in the Calvin cycle after the fixation of carbon dioxide in C₃ plants. The first product, an unstable 6-carbon compound, is formed when carbon dioxide combines with ribulose diphosphate.

A. Black arm of cotton : X. campestris pv. Malvacearum.
Bacterium malvacearum, the causative agent of 'black-arm', or angular leaf-spot disease of the cotton plant.
B. Bacterial leaf blight of rice : Xanthomonas campestris pv. Oryzae.
Xanthomonas oryzae pv. oryzae causes bacterial blight (BB) of rice which is one of the most important diseases of rice in most rice-growing countries.
C. Red stripe of sugarcane : Pseudomonas rubrilineaus.
The pathogen attacks sucrose accumulating parenchyma cells of cane stalk leading to severe losses in cane yield and sugar recovery.
D. Ergot of bajra is not caused by Erwinia carolovora.
It is caused by Claviceps fusiformis is an important and widespread disease in India. The disease causes direct grain yield loss by replacing grains with toxic alkaloid-containing sclerotia, making the produce unfit for consumption.

Damping off and leaf blights are very effectively checked by Copper oxychloride.
Damping off is a horticultural disease or condition, caused by several different pathogens that kill or weaken seeds or seedlings before or after they germinate. It is most prevalent in wet and cool conditions.
Leaf blight disease is caused by fungus. The disease develops on leaves, on sorghum particularly under humid conditions by producing reddish-purple or tan spots that coalesce to form large lesions.
Spraying or drenching the soil with a recommended anti-fungal treatment, such as copper oxychloride helps suppress the disease.

Chestnut compound was first used for Damping off.
Chestnut compound was first suggested by Bewley in 1922 and is used especially to control damping-off diseases of seedlings.
The Chestnut compound contains two parts of copper sulphate and 11 parts of ammonium carbonate. The two substances are well powdered and thoroughly mixed and the dry mixture is stored in an airtight receptacle for 24 hours before being used.

Haploid plant cultures are produced from Pollen grains.
Haploid culture is an in vitro technique used to produce haploid (cells have half the number of chromosomes) plants.
Blackslee in 1922 first reported the natural occurrence of the haploid condition in Datura plants, due to parthenogenesis.
Haploid plants can be produced through in vitro culture of male gametophytic cells at the microspore or immature pollen developmental stage.

Phosphorus is a nutrient that is available at a neutral pH value.
Precipitation of phosphorus as slightly soluble calcium phosphates occurs in calcareous soils with pH values around 8.0.
Under acid conditions, phosphorus is precipitated as Fe or Al phosphates of low solubility. Maximum availability of phosphorus generally occurs in a pH range of 6.0 to 7.0.