What is vertical and horizontal resistance?
Genetic resistance that is effective at preventing successful attack only by certain races of a pathogen is called specific (or vertical) resistance, whereas resistance that is effective at preventing successful attack by all races of a pathogen is called general (or horizontal) resistance.
What is boom and bust cycle in plant pathology?
The “boom-bust cycle” of resistance genes refers to the widespread use of a single resistance gene that protects multiple varieties of a grain from a disease (boom). When the disease overcomes this resistance gene many varieties simultaneously become susceptible (bust).
How does vertical resistance work?
Vertical resistance, conferred by the R-genes, is oligogenic, and can be overcome by a change of race. Horizontal resistance slows down the rate at which disease increases in the field. Vertical resistance reduces the initial amount of inoculum from which the epidemic begins.
What are the four components of GDP?
The four components of GDP—investment spending, net exports, government spending, and consumption—don’t move in lockstep with each other.
What causes boom and bust?
Three forces combine to cause the boom and bust cycle. They are the law of supply and demand, the availability of financial capital, and future expectations. These three forces work together to cause each phase of the cycle. … If demand outstrips supply, the economy can overheat.
What is recession investopedia?
A recession is a macroeconomic term that refers to a significant decline in general economic activity in a designated region. It had been typically recognized as two consecutive quarters of economic decline, as reflected by GDP in conjunction with monthly indicators such as a rise in unemployment.
What is a boom cycle?
A boom-bust cycle is a series of events in which a rapid increase in business activity in the economy is followed by a rapid decrease in business activity. … A boom-bust cycle is a series of events in which a rapid increase in business activity in the economy is followed by a rapid decrease in business activity.
How do phytoalexins work?
Phytoalexins are produced in plants to act as toxins to the attacking organism. They may puncture the cell wall, delay maturation, disrupt metabolism or prevent reproduction of the pathogen in question.
What is phytoalexin example?
Gossypol from cotton, casbene from castor bean, and rishitin from plants in the Solanaceae are examples of phytoalexins biosynthesized by the mevalonic acid pathway (Fig. … Increases in the levels of phytoalexin biosynthetic enzymes themselves are due to increased expression of the genes encoding the enzymes.
What is Phytoalexins in plants?
Phytoalexins are low molecular weight antimicrobial compounds that are produced by plants as a response to biotic and abiotic stresses. As such they take part in an intricate defense system which enables plants to control invading microorganisms.
What is phytoalexin in plant pathology?
A phytoalexin is a compound which inhibits the developmentof the fungus in hypersensitive tissues and is formed or activated only when the host plants come in contact withthe parasite.
Is it boon or bust or boom or bust?
Resulting in an outcome that will either be very good or very bad. Many professional athletes face a boom or bust situation early in their career, where they are either drafted to a professional league or don’t advance at all.
What is vertical resistance in plant disease?
resistance to plant diseases are vertical (specific) and horizontal (nonspecific). A plant variety that exhibits a high degree of resistance to a single race, or strain, of a pathogen is said to be vertically resistant; this ability usually is controlled by one or a few plant genes.
What is the difference between boom and bust?
During the boom the economy grows, jobs are plentiful and the market brings high returns to investors. In the subsequent bust the economy shrinks, people lose their jobs and investors lose money. Boom-bust cycles last for varying lengths of time; they also vary in severity.
What happens in a bust?
A bust is a period of time during which economic growth decreases rapidly. In the stock market, busts usually are associated with bear markets. During busts, inflation decreases, and in extreme cases, can give way to deflation. In addition, unemployment rises, income falls, and aggregate demand decreases.
What causes wilt disease?
Bacterial wilt, caused by numerous species of the genera Corynebacterium, Erwinia, Pseudomonas, and Xanthomonas, induces stunting, wilting, and withering, starting usually with younger leaves. Stems, which often shrivel and wither, show discoloured water-conducting tissue.
What are the 4 stages of the business cycle?
The four stages of the cycle are expansion, peak, contraction, and trough. Factors such as GDP, interest rates, total employment, and consumer spending, can help determine the current stage of the economic cycle.
How do I stop wilting?
- Ensure that the plant needs watering. …
- Move the wilted plant out of the sun, if possible.
- Set wilted container plants with dry soil in a sink or tray filled with water.
What are the sources of disease resistance in plants?
Disease control is achieved by use of plants that have been bred for good resistance to many diseases, and by plant cultivation approaches such as crop rotation, pathogen-free seed, appropriate planting date and plant density, control of field moisture, and pesticide use.
How is wilt disease treated?
How to Control Fusarium Wilt: Once fusarium wilt infects a plant, there is no effective treatment. Remove and dispose of affected plants immediately; don’t compost this garden refuse. Whenever possible, remove and replace fusarium-infected garden soil.
What are the types of wilting?
Temporary wilting: On hot summer days, the freshness of herbaceous plants reduces turgor pressure at the day time and regains it at night. Permanent wilting: The absorption of water virtually ceases because the plant cell does not get water from any source and the plant cell passes into a state of permanent wilting.
What is gene deployment?
Alternate approaches of gene deployment: Gene deployment is the guided distribution of genes in space and time. Gould divided the gene deployment strategies in to two broad categories as 1) spatial (gene deployment at the farm level, at the field level and at the region level) and 2) temporal.
What is the mechanism of disease resistance in plants?
Plant immune systems rely on their ability to recognize enemy molecules, carry out signal transduction, and respond defensively through pathways involving many genes and their products. Pathogens actively attempt to evade and interfere with response pathways, selecting for a decentralized, multicomponent immune system.
How can plant resistance be improved?
Due to the low difficulty of the process and the good results that we can obtain, annealing a PLA object is one of the best ways to significantly increase the strength and heat resistance of PLA objects. By annealing a PLA object, I mean slowly heating it up to 60°C (140°F) or slightly above, but below 160°C (320°F).
What is canker in plants?
canker, plant disease, caused by numerous species of fungi and bacteria, that occurs primarily on woody species. Symptoms include round-to-irregular sunken, swollen, flattened, cracked, discoloured, or dead areas on the stems (canes), twigs, limbs, or trunk.
Why are disease resistant crops good?
Harnessing host resistance through crop breeding offers an effective and reliable alternative to pesticides3 that can be combined with other management practices in integrated approaches. For example, disease-resistant crops perform better with timely planting and harvest and with crop diversification4.
What is gene for gene concept?
The gene-for-gene relationship was discovered by Harold Henry Flor who was working with rust (Melampsora lini) of flax (Linum usitatissimum). Flor showed that the inheritance of both resistance in the host and parasite ability to cause disease is controlled by pairs of matching genes.
What is resistance to disease called?
Immunity means com- plete resistance to disease; immune means not subject to attack by a path- ogenic organism or virus.
What is multiline concept?
The term Multiline Genetics is used for a variety is a composite of genetically identical lines, except that each line possesses a different gene for resistance to the disease. This is also called Multiline Varieties. In the event of occurrence of a new race, some plants may be susceptible, but not all.
Why is it called canker?
Canker sores, also called aphthous ulcers, are small, painful sores that appear inside the mouth on the lips, cheeks, on the gums, and tongue. They are appropriately named, too: In Greek, aphthae (root of aphthous) means “to set on fire.” Canker sores are not contagious and can’t be spread through saliva.
Who introduced the term Vertifolia effect?
This phenomenon was first described by J.E. Van der Plank in his 1963 book Plant Disease: Epidemics and Control.
What is gene pyramiding in plants?
Gene pyramiding refers to the process of stacking multiple genes into a single genotype to combine desirable traits through recombinant DNA technology or conventional breeding. This approach has resulted in the so-called ‘second generation’ of GE plants.
What trees are affected by canker?
Nectria canker tends to attack deciduous shade trees, crabapples and pears. Cytospora canker is found most often in fruit trees, hardwood forest trees and shrubs, as well as over 70 species of conifers. Hypoxylon canker is seen in different species of oak, including red and white.
What is durable disease resistance?
Durable disease resistance is defined as resistance that has remained effective while a cultivar possessing it has been widely cultivated in an environment favoring the disease. This characteristic of resistance is recognised retrospectively, as are all other characteristics of interactions between hosts and pathogens.
What organism causes cankers?
Diseases. Bacterial canker, one of the most important sweet and sour cherry pathogens, is caused by two different pathogens, Pseudomonas syringae and P. morsprunorum, and is characterized by oozing of gum (gummosis) at infection sites. Disease development is most prevalent during the cool, wet periods of early spring.
What is meant by Oligogenic?
(ŏl″ĭ-gō-jĕn′ĭk, -jēn′) Caused by, affecting, or relating to a small number of genes.
Who described vertical resistance and horizontal resistance?
The term vertical resistance, used commonly in context of plant selection, was first used by J.E. Vanderplank to describe single-gene resistance. This contrasted the term horizontal resistance which was used to describe many-gene resistance. Raoul A.
What are R proteins?
The R protein guards another protein that detects degradation by an Avr gene (see Guard Hypothesis). The R protein may detect a Pathogen-Associated Molecular Pattern or PAMP (alternatively called MAMP for microbe-associated molecular pattern). The R protein encodes enzyme that degrades a toxin produced by a pathogen.