CPRT Lec 5 - Genetic Control of Insect Pests Flashcards
yagballs
It is the manipulation of genetic components or other inheritance mechanisms in an organism.
Genetic Control
Most widely used technique of Genetic Control
Sterile Male Technique/ Sterile Insect Technique
This procedure involves mass-rearing insects, subjecting them to sterilization by irradiation or chemical mutagens, and releasing large numbers of males to mate with wild females
SMT/SIT
Example of chemical sterilant
tris-(1-aziridinyl) phosphine oxide
is tris-(1-aziridinyl) phosphine oxide carcinogenic?
Yes lol and should be used with caution
When was SIT developed?
1940s and 1950s
Which insects did SIT programs have effectively eradicated?
Screwworm in North and Central America; Mediterranean Fruit Fly in Florida;
What suppresed fruit fly populations in mangoes?
Sterile Insect Technique and Male Annihilation Technique
Im which area/institution were fruit fly populations suppresed in mangoes?
Guimaras, Iloilo with collaboration of Philippine Nuclear Research Institute and National Mango Research and Development Center
Is the heritable property that enables a plant to inhibit pest population growth or recover from an injury caused by populations not inhibited from groing
Resistance
How are genes from wild relatives of crops utilized?
deployed in different crops to make the plants resistant
considered a false resistance or pseudo resistance because it is under the primary control of the crop’s environment.
Ecological resistance
right and real resistance because it is governed by resistance genes inherent to various introduced cources
Genetic resistance
2 types of Ecological Resistance
Phenological asynchrony and Induced Resistance
In ______, the crop/s susceptible stage does’nt coincide with the pest population’s peak such that the plant escapes the damage
Phenological asynchrony
________ is brought by the plant’s proper care such as fertilization and other practices that make them resistant to insect pest attack
Induced Resistance
A type of resistance under the primary control of the plants’genetic factors and is consiered real resistance
Genetic resistance
Three mechanisms of insect resistance (Painter 1951)
non-preference, antibiosis, and tolerance
Non-preference was later named ____ by Kogan and Ortman (1978)
Antixenosis
Occurs when a pest is less likely to find or feed on a resistant plant
Antixenosis
Occurs when feeding on a resistant plant harms the pest’s health or fitness
Antibiosis
Occurs when a plant can continue to thrive despite being attacked
Tolerance
Defined as the host plant’s ability to exclude or overcome a pathogen’s effect entirely or to some degree
Host Plant Resistance
The use of ____, if available, is perhaps the best pest control method for managing pest and disease problems
Resistant varieties
Rice tungro disease-resistant lines were also released by NSIC (formerly Philippine Seed Board) under the popular name:
Matatag Lines
also called as passive type resistance
Pre-formed resistance
also called as active type resistance
Induced resistance
the host plant’s ability to reduce the effect of infection on its fitness regardless of the level of pathogen multiplication so it can still have its normal yield despite disease infection.
Tolerance
Examples of pre-formed resistance mechanisms?
- Structural barriers (thick plant cuticle, waxy cuticle, partially closed stomates)
Includes mechanical barriers, hypersensitive reaction, phytoalexin production, toxic metabolite production against pathogen, detoxification of toxins made by the pathogen
Induced resistance
is the rapid localized death of host cells around the invading pathogen. It results in confinement and even death of the pathogen
Hypersensitive reaction
substance produced by the infected plant that inhibits development of a pathogen
Phytoalexin
Plants infected with one pathogen become more resistant to subsequent infection by another pathogen
Systemic acquired resistance
Parts of the pathogens that can induce plant’s resistance
Plant defense activators/ resistance elicitors
When a mild strain of a virus when inoculated to a healthy plant can protect the plant from an aggressive strain of the same virus, the phenomenon is called
Cross-protection
Examples of identified plant defense activators
- Chitosan, isalicylic acid, acetylsalicylic acid (aspirin), dichloroisonicotinic acid
is effective in inducing resistance of tomato bacterial wilt, rice bacterial blight, and abaca bacterial heart rot
Chitosan
If the resistance gene to be transferred is dominant, it takes at least _______ within ____
four backcrossing rounds within seven seasons
If the gene is recessive, this process requires more generations of selfing, thus ______
nine or more cropping seasons
short cut method of introgressing or transferring a pest resistance gene from a donor to an elite one
Genetic engineering of crops
it introduces specific DNA sequences into crop plants to enhance insect pests’ resistance
Genetic engineering of crops
Factors needed for Gene Insertion/ Gene Transfer
- Gene (gun)
- Bacterial vehicle (Agrobacterium tumeraciens)
- or a chemical/electrical treatment (electroporation)
Engineers must also insert a “prmoter” gene from a virus as part of the package to make the inserted gene ___
express itself
What gene was genetically inserted to Bt corn and Bt cotton?
Cry gene from Bacillus thuringiensis
Bt corn and Bt cottons confers resistance against
Corn borer and cotton bollworm
PRSV-resistant (Hawaiian) transgenic papaya variety SUnUp was developed by
somatic embryos with the coat protein (CP) gene of the Hawaiian papaya ringspot virus strain
