Host Plant Resistance

7/25/2019 Host Plant Resistance

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Discuss host plant resistanceINTRODUCTION

Host plant resistance is a plant that possess special features orcharacteristic that enable the plant to protect itself from any pest that

attack it especially insects or microbes. There is a research onModelling the eects of host plant resistance on plant diseaseepidemics. In the research, the researcher used research loop that issimulation model to enable him/her to assume the result from his/herchoices.

INDUCTION PHASE

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DEDUCTION PHASE

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This simulation model enable great understanding bet4een thebreeders, molecular geneticists, and plant disease epidemiologists.

ther than that, it enables, the obser5er to see things that beenhidden that is can not be obser5e at system le5el in the 6eld, region orthe plant. In plant, there are many 5arieties of resistance mechanismbut there is a plant that naturally has resistant to the pest. Mechanismslike morphological and physiological been used by plant to protectthemsel5es. #7amples of morphological mechanism are plant hasthick cell 4alls that enable the plant to protect the tearing action ofinsects and 4a7 also may interfere 4ith insect mo5ement on surface ofleaf. on5entional breeding been use to de5elop pest resistanceculti5ar by selecting good breeding lines and through introduced geneinto plant genome. The bene6t of using this host plant resistance is

free chemical pesticides and safe. Mean4hile, "terile Insect Techni8ue9"IT: is de6ned as a release sterile insects in a 6eld population of samespecies to reduce reproduction of 4ild trait. Male insects been releasedinto its population so that it mated 4ith nati5e female insects toproduce sterile population generations or fail of sur5i5al of the 4ildospring. This method relies on gamma rays to sterili;e insects. Theimportant part in successful mating 4ith nati5e female insects is thesterile males must be more than 4ild males in the area.

CONTENT

In plant host resistance there are t4o types of resistance. 1irstly,ecological resistance or )seudo resistance and secondly geneticresistance.

In ecological resistance/)seudo resistance,there are < categories. 1irsthost e5asion. The plant host may undergo the insect attack at a time4hen the percentage of insect is decrease or at a time maturing phase

Type of )lant

#cologicalresistance/)seudo

Host e5asion Induced resistance

'enetic resistance !ased on number of genes

!ased on biotype of reaction

!ased on population/*ine

concept


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of plant. "econdly, induced resistance. This induced resistance helpplant by taking ad5antage at the time 4hen plant lack of nutrientuptake. Thirdly, escape resistance. +uring incomplete or no infestation,the host plant sur5i5e. This only relate to fe4 plant host. In geneticresistance, there are = categories. 1irst, based on number of genes.

There are monogenic, oligogenic, polygenic,ma>or gene,minor generesistance, "econdly, based on biotype of reaction. There are 5erticalresistance and hori;ontal resistance. %ertical resistance only eecti5eon speci6c biotypes 4hile hori;ontal resistance eecti5e to all kno4nbiotypes. Then, based on population/ *ine concept. There are purelineand multiline resistance. 1or pureline resistance only has on the similarphenotypically and genetically lines. Multiline resistance has onphenotypically similar but genotypically dissimilar lines. *astly, formiscellaneous categories. There are cross and multiple resistance. 1orcross resistance, the host plant has 5arieties of resistance against theprimary pest. Then, multiple resistance against many en5ironmental

stresses such as disease, nematodes, heat, and etc.

1or the mechanism of plant resistance, there are < mechanismsin5ol5ed in host plant resistance. 1irstly, antixenosis. nti7enosis isthe non?prefer plant for insect to feed, o5iposition and etc.Thisanti7enosis alter the the insecst beha5ior by the present of chemicaland morphological plant factors. This gi5e the bene6ts to the plantbecause the insect has to choose other host plant to increase itspopulation."econdly, antibiosis. This mechanism gi5e negati5e impact on insectby biochemical and biophysical factors that has in plant. !oth

biochemical and biophysical factors eect insects by reduce insect4eight, early instar die, immature stages of insect been e7tend, andetc. *astly, tolerance. Tolerance mechanism enable plant to 4ithstandattack from insect by its inherent ability. The presence of tolerance inplant can be measured by comparing the plant damage, the plantbiomass production bet4een infested and noninfested plant for sameculti5ar plant.

+e5elop a crop that has high in resistance to insect can be done bydetermine the resistance gene in a gi5en pest and then put the geneinto the plant 5arieties that 4e 4ant to impro5e through back cross?

breeding. Many breeding strategies been de5elop such as genepyramiding, se8uential release, gene deployment and multilines. Incurrent inno5ati5e strategies like tissue culture techni8ues, 4idehybridi;ation and molecular marker?aided selection been done toincrease the insect resistance crop 5arieties. 'enetic transformationalso aid in produce insect crop resistance by insert genes of resistanceinsect into plant genome. Transgenic crop gi5e many ad5antages likeeco?friendly, eecti5e in targetting insects, 6nancial sa5ings to


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customer and etc. This transgenic technology should be no harm tonatural enemies. !acteria like Bacillus thuringiensis has been recordsuccessfully in genetic transformation for controlling pest. #7amples ofcrop are mai;e, potato, cabbage, broccoli, alfalfa and cotton. Insertionof Bacillus thuringiensis gene into tobacco plant chloroplast genome

has pro5e the successful of trangenic technology. There are t4o ma>orplant?deri5ed genes that been use for insect resistance to the crop.There are lectins and inhibitor of digesti5e en;ymes. This both genesbeen transfered to crop 4ith similar le5el of gene !t to7ins. )lantfamilies "olanaceae, 1abaceae, and )oaceae been concentratedagainst coleopteran, lepidopteran and orthopteran by using inhibitor ofdigesti5e en;ymes gene that has on this families. 1or lectins, lectinsalso ha5e sho4s some characteristics against insects species of orders+iptera, oleoptera, and Homoptera. In sno4drop9'&: from lectinshas to7ic agains aphid. 5erall, host plant resistance is 5ital inproducing better crop and impro5ed food security. This host plant

resistance gi5e no harm to natural enemies. It also less cost to farmerfor increasing its crop yield. "ome 5arieties of plant has long durationof resistance. The disad5antage of plant host resistance are its timeconsuming because it takes long time to de5elop a 5ariety thatresistance to certain insects. Then, genes among a5ailable germinationplants are absence of resistance.

oncept of "terile Insect Techni8ues

oncept of "terile InsectTechni8ues

sing insect tocontrol themsel5es

Their reproducti5ecapacity is reduce

+rosophila fruit 6les 4as

disco5ered by [email protected] that fruitAiescan be se7ually sterili;ed

+ominant lethalmutations been

This thought 4ascon6rmed by Bnipling

and !ushland onscre44orm Aies.

*ast endemicscre44orm case

4as recorded inAorida in CDED using

Tu7tla 'utierre;,haiapas, Me7ico,eastern panama, &orthmerica 4ere selectedcountries for this "IT


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1irst insect pest control method using genetics is "terile InsectTechni8ue. It been done spread of sterile male into 4ide area to bemate 4ith nati5e females to produce sterile insect species. This "ITin5ol5es by e7posing them to lo4 dose of radiation then released intotargeted area 4here they 4ill mate 4ith 4ild female of its population.!efore this, "IT 4as used to eradicate &e4 3orld "cre44orm 9&3":from &orth frica.

utocidal 4as a type of pest control that use manipulation techni8ue

"terile Insect Techni8ue

!iological based method9utocidal:

$adiationsterili;ed males

"pecies speci6c &on?polluting

$esistance free )est populationnumbers 4ere


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on target insect so that it can control of its o4n kind , or literally FkillsitselfF.

utocide is eecti5e 4hen applied to restricted populations. It takes or 4ay to decrease the 4ildpopulatin insects. 1or cotton crop in alifornias "an @oa8uin %alley, thesterile pink boll4orms and strile Me7ican fruit Aies are relaesed to itspopulation to mate 4ith the nati5e female to fail the 4ild ospring isone of the e7ample for pre5ention method.

CONC"USIONIn conclusion, host plant resistance is good for crisis in food securityand for farmer to reduce the cost in pre5ent pest attack. +e5eloping a

good host plant resistance is not easy but 4ith help from breeders,molecular geneticists, and plant disease epidemiologists, by theirresearch and e7perimental design it bring a lots of bene6t tohumankind. "IT techni8ues also one of the good strategies thatreduces the pest population. This "IT method been using all around the4orld due to its eecti5eness in pre5ent damage in plant. This insectpest control bring ne4 hope to the farmers to increase their produceyield.

In -aeyama Island, melon fruit

Ay 6rst found in CDCD. The melon fruit Ay is spread to

southern island of @apan andthen make damage to many

hosts in CDG. program be done by @apanese

go5ernment to make the melonfruit A disa ear from

'uatemala, Me7ico and the

nited "tates signedagreements for establish)rogram Moscamed.

The aim is by containment

Mediterranean fruit Ay, in'uatemala and pre5ent itfrom 4ide its population intoMe7ico and ".

The result is the agricultural

product and produce fromMe7ico is increasing in a


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RE#ERENCESLecture 16: Host Plant Resistance - Definition- Types and Mechanism Ecological and enetic

Resistance! Retrie"ed Decem#er $6% $&1'

(e#site:http:))agridr!in)tnauE*gri)eagri'&)E+T,$$)lec16!pdf

.hapter 6! Modeling the Effects of Host Plant Resistance on Plant Disease Epidemics! Retrie"ed

Decem#er $6% $&1'

(e#site:

http:))(((!apsnet!org)edcenter)ad"anced)topics)/otanicalEpidemiology)Documents)Do(nloads)chapt

er6!pdf

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