Plant Pathology MCQ Question and Answer | Agriculture MCQ Question

The embryo sac is monosporic when it develops from one of the four megaspores of a megaspore mother cell.
In monosporic development, the egg apparatus is organized from a group of four nuclei at the micropylar pole of the syncytial embryo sac. These nuclei are derived from the chalazal megaspore of the tetrad.
One cell of the nucellus undergoes meiosis to produce four megaspores. One megaspore survives and undergoes three rounds of the free nuclear division followed by cellularization to produce an embryo sac consisting of 8 nuclei in 7 cells.
At the micropylar end, two peripheral cells develop into synergids (which attract the pollen tube for sperm delivery), and the third cell differentiates into the egg cell.

Nephantis serenopa is responsible for the damage to the Coconut.
Nephantis serinopa is the only species within the genus Nephantis. The wingspan is 20 - 28 mm. The forewings are pale greyish-ochreous, with some fine scattered blackish scales and with the extreme costal edge whitish.
The first discal stigma is raised, and dark fuscous, the plical and second discal indistinct, indicated by two or three dark fuscous scales, the plical obliquely before the first discal.
The larvae conceal themselves beneath galleries of web and excreta on the under-surface of the leaves of the coconut palm.

PR Proteins accumulate in the Apoplast & vacuole.
Pathogenesis-related (PR) proteins are proteins produced in plants in the event of a pathogen attack.
These are structurally diverse groups of plant proteins that are toxic to invading fungal pathogens. They are widely distributed in plants in trace amounts but are produced in much greater concentrations following pathogen attack or stress.
Pathogenesis-related proteins are a class of proteins that accumulate in response to biotic and abiotic stresses to protect plants from damage in the apoplast and vacuole.

The embryo sac occurs in Ovule.
The embryo sac develops within the ovule surrounded by the nucellus, which is in turn surrounded by the integuments. One cell of the nucellus undergoes meiosis to produce four megaspores.
A mature ovule consists of a food tissue covered by one or two future seed coats, known as integuments. A small opening (the micropyle) in the integuments permits the pollen tube to enter and discharge its sperm nuclei into the embryo sac, a large oval cell in which fertilization and development occur.

Aldicarb and Phorate are the nematicides group which are nonfumigant in nature.
Non-fumigant nematicides available for vegetable production in Florida include two broad categories, chemical nematicides, and biological nematicides.
Aldicarb is a carbamate insecticide that is the active substance in the pesticide Temik. It is effective against thrips, aphids, spider mites, lygus, fleahoppers, and leafminers, but is primarily used as a nematicide.
Phorate is an organophosphate used as an insecticide. It is very toxic both for target organisms and for mammals including humans.

Panama wilt is a disease of Bananas.
Panama disease, also called banana wilt, is a devastating disease of bananas caused by the soil-inhabiting fungus species Fusarium oxysporum forma specialis cubense.
A form of fusarium wilt, Panama disease is widespread throughout the tropics and can be found wherever susceptible banana cultivars are grown.

MLO disease transmitted by Leafhopper.
Mycoplasma-like organisms (mycoplasmas, spiroplasmas and rickettsias) are generally considered to be somewhere between bacteria and viruses in size, shape and function.
Mycoplasma-like organisms (MLOs) are microorganisms lacking cell Walls that cause phyllody and witches' broom as well as yellows diseases in various crop plants in Asia.
These organisms are the cause of 'yellows' type diseases and are transmitted to plants during leafhopper feeding.

Metalaxyl fungicide is used against Downey mildew.
Metalaxyl is a systemic fungicide used to control air- and soil-borne diseases on a wide range of crops, as well as foliar diseases caused by the Downey mildews.
It is used to control plant diseases caused by Oomycete fungi. Its formulations include granules, wettable powders, dust and emulsifiable concentrates.

PRO-PLANT Expert system deals with Cereals, potatoes and Sugarbeet.
PRO PLANT is a consulting system for environmentally friendly plant protection in agriculture. The analysis of the weather-dependent infection events of fungi and the infestation development of parasites allows an exact determination of the time of spraying and reduces, with simultaneous high yield certainty, the number of sprayings to be carried out and their application rates.

The ovule is inverted with the body fused to the funicle, the micropyle lying close to the hilum and facing the placenta. It is Anatropous.
An anatropous ovule is having or being a plant ovule inverted so that the micropyle is bent down to the funiculus to which the body of the ovule is united.
It is one in which curvature during development results in the displacement of the micropyle to a position adjacent to the funiculus base, this is the most common ovule type of the angiosperms and is presumed to be ancestral.