FACTORS INDUCING RESISTANCE AGAINST INSECT PEST OF RICE

COLLEGE OF AGRICULTURE,
OUAT,BHUBANESWAR
DEPARTMENT OF ENTOMOLOGY
FACTORS INDUCING RESISTANCE AGAINST
INSECT PESTS OF RICE
MASTER’S SEMINAR (ENT-591)
Presented By-
Aishwarya Dash
07ENT/17
2

RESISTANCE-
• Resistance of a plant to an insect is defined as
the 'relative amount of heritable qualities possessed by
the plant which influences the ultimate degree of damage
done by the insect' (Painter 1968).
3

INDUCED RESISTANCE-
• Induced resistance is the qualitative or quantitative enhancement of
the plant’s defense against invading organisms in response to pest
related injury or extrinsic physical or chemical stimuli.
• The extrinsic stimuli are known as inducers or elicitors.
• The post challenge or injury-dependent responses of plants are
components of induced resistance (Kogan & Paxton 1983)
• This is a non-heritable resistance wherein the host-plants are induced
to impart resistance to tide over the pest infestation.
4

WHY INDUCED RESISTANCE IS
CONCERNED-
• Minimizes use of insecticides.
• Suitable for IPM.
• More concern towards organic farming & ZBNF.
• Conserves Natural enemy population
• Environment friendly.
• Reduces resurgence of pests
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808782/
6

• This is possible by-
• Manipulation of fertilizer application, chelates, biofertilizers, organic
amendments etc. Such manipulations also bring about changes in
biochemicals of the host-plants.
• Application of higher doses of potassium confers resistance to some
pests.
• Decreased infestation of leaf folder, thrips, brown planthopper, green
leaf hopper and stem borer has been reported in rice (Chelliah 1985b).
• Among the chelates, Zn EDTA complex has been reported to induce
resistance in rice to the leaf folder and stem borer (Devanathan 1981).
7

CHARACTERISTICS REQUIRED-
The following characteristics will increase the feasibility of using
induced resistance in specific agricultural systems (following Karban &
Baldwin, 1997):
(i) the pest must be destructive (costly) and difficult to control by other
means;
(ii) the inducer must not be a pest itself or cause significant losses in
yield;
(iii) it must be feasible to introduce the inducer into the system;
(iv) the inducer should be sustainable (perhaps self-replicating); and
(v) the plant must have some tolerance of the pest.
All of these conditions contribute to the cost effectiveness of
induced resistance.
8

• 3 strategies that use induced resistance to protect crop plants. ( R. Karban
& Y. Chen 2007)
• 1. Avirulent organisms can be introduced to protect crops against
economically damaging pests.
• 2. chemical pathways that lead to induced resistance, it may become
feasible to use natural or synthetic chemical elicitors of induced responses.
• 3. genetics and molecular control of resistance, it may become feasible for us
to selectively express resistance traits that are naturally inducible.
Genetic manipulations enable us to move induced resistance traits
from resistant varieties and species into susceptible varieties that have
desirable agronomic characteristics 10

INSCECT PESTS OF RICE CONTROLLED
THROUGH INDUCED RESISTANCE-
R. Karban & Y. Chan
(2007)
COMMON NAME SCIENTIFIC NAME FAMILY ORDER
Rice leaf folder Cnaphalocrocis
medinalis
Pyralidae Lepidoptera
yellow stem borer Scirpophga incertulus Pyralidae Lepidoptera
Striped rice borer Chilo suppressalis Pyralidae Lepidoptera
BPH Nilaparvata lugens Delphacidae Hemiptera
WBPH Sogatella frucifera Delphacidae Hemiptera
Gall midge Orseolia oryzae Cecidomyiidae Diptera
11

RICE LEAF FOLDER
RICE YSB
http://www.knowledgebank.irri.org/step-by-step-
production/growth/pests-and-diseases/insects
GALL MIDGE
12

http://www.knowledgebank.irri.org/
BPH WBPH
13

A multitude of factors are reported to induce resistance in
plants.
1.Elicitors of biotic origin
a.Beneficial microbes
b.insects
c.Organic source
2.Elicitors of abiotic origin
a.Chemical elicitors
b.Herbicides
c.Fertilizers
d.Mineral nutrients ( Si, Zn, Fe fertilizers)
FACTORS INDUCING RESISTANCE-
R. Karban & Y. Chan (2007)
15

BENEFICIAL MICROBES
•Pseudomonas & Rice Leaf folder
• Fluorescent Pseudomonas strains Pf1, TDK1 and PY15
individually and in combination were evaluated against leaf
folder, Cnaphalocrocis medinalis in rice under in vitro,
glasshouse and field conditions.
• Among the various treatments used, a combination of Pf1,
TDK1 and PY15 strains effectively reduced the incidence of leaf
folder pest in rice plants to an extent comparable with
chlorpyrifos-methyl.
( Saravanakumar et
al.,2007)
17

• In addition, morphogenesis of the insect pest in all stages,
larval, pupal and adult, was greatly affected by a
combination of Pseudomonas Pf1, TDK1 and PY15 strains.
Further, the induction of defence-related molecules was
demonstrated. An increased accumulation of defence
molecules such as chitinase and proteinase inhibitors was
observed with a combined Pf1, TDK1 and PY15 treatment
compared with all other treatments.
( Saravanakumar et al.,2007)
18

Effect of fluorescent Pseudomonas mixtures on the
morphogenesis of Cnaphalocrocis medinalis: 1, Pf1 + TDK1 + PY15;
2, TDK1; 3, Control. 19

• Escherichia coli & BPH
• BPH honeydew strongly elicits direct and putative indirect defences in
rice, i.e., accumulation of phytoalexins in the leaves, and release of
volatile organic compounds from the leaves that serve to attract
natural enemies of herbivores, respectively.
• Elicitor active components in the honeydew is bacteria in the
secretions are responsible for the activation of plant defence. It
increases secondary metabolite levels. Two rice phenolamides,
p-coumaroylputrescine (CoP) and feruloylputrescine (FP), were strongly induced at
24 h after addition of 2 μL crude BPH honeydew to 1 mL cultivation media with
cells
• Escherichia coli DH5α (a derivative of E. coli K12) was used as a
standard to validate the Induced resistance method. ( Wari et al.,2019)
20

RESISTANCE OF RICE TO INSECT PESTS
MEDIATED BY SUPPRESSION OF SEROTONIN
BIOSYNTHESIS
• Biosynthesis of serotonin, a neurotransmitter in mammals , is
induced by insect infestation in rice, and its suppression confers
resistance to planthoppers and stem borers, the two most destructive
pests of rice.
• Serotonin and salicylic acid derive from chorismate . In rice, the
cytochrome P450 gene CYP71A1 encodes tryptamine 5-hydroxylase,
which catalyses conversion of tryptamine to serotonin . In susceptible
wild-type rice, planthopper feeding induces biosynthesis of serotonin
and salicylic acid, whereas in mutants with an inactivated CYP71A1
gene, no serotonin is produced, salicylic acid levels are higher and
plants are more insect resistant.
R. Karban & Y. Chan (2007)
22

• The addition of serotonin to the resistant rice
mutant and other brown planthopper-resistant
genotypes results in a loss of insect resistance.
Similarly, serotonin supplementation in artificial
diet enhances the performance of both insects. These
insights demonstrate that regulation of serotonin
biosynthesis plays an important role in defence, and
may prove valuable for breeding insect-resistant
cultivars of rice and other cereal crops.
Karban et al., 2007
23

• OVICIDAL COMPOUNDS-
• Some cultivars of Japonica rice produce watery lesions rapidly at
the site of oviposition in response to white backed planthopper
eggs (Suzuki et al., 1996) and to a lesser degree to brown
planthopper eggs.
• These watery lesions contain an ovicidal compound, benzyl
benzoate, which causes high rates of egg mortality (up to 80%
depending upon cultivar, developmental stage and other factors).
• No ovicidal substance was detected in undamaged plants or in
locations away from oviposition sites on damaged plants
(Yamasaki et al.,
24

• HYPERSENSITIVITY-
• Rice seedlings of a resistant variety Phalguna exhibit a hypersensitive
response including localized necrosis immediately surrounding the
oviposition sites in reaction to several biotypes of the Asian rice gall midge,
Orseolia oryzae (Bentur & Kalode, 1996; Sardesai et al., 2001).
• This hypersensitive response caused 100% mortality of first instar maggots
within four days. Tillers that were produced subsequently by these induced
plants were well protected against avirulent biotypes. In addition, seedlings
that had been exposed to an avirulent biotype gained resistance against
more damaging biotypes of the rice gall midge;
• Resistance induced by the avirulent midges continued to protect plants for
several weeks (Bentur & Kalode, 1996).
• This suggested that releases of the avirulent biotype could protect plants
against the spread of more damaging biotypes.
25

• VOLATILE COMPOUNDS-
• Rice plants that are attacked by armyworm or cluster caterpillars
(Spodoptera litura) release blends of volatile compounds that are
repellent to brown planthoppers (Xu et al., 2002).
• Adult brown planthopper females were less likely to choose rice plants
damaged by caterpillars compared with undamaged plants,
mechanically damaged plants or plants infested with brown
planthoppers in dual choice experiments conducted in flight tunnels.
This result indicates that induced plant volatiles could be used to
make plants less attractive to important pests such as brown
Planthoppers. (Xu et al., 2003; Zhou et al., 2003).
26

• Inorganic fertilizers provide large amount of nutrients in
relatively short period of time resulting in luxuriant crop
growth which led to heavy insect population.
• Organic manures work like slow release fertilizers thus
providing balanced nutrition to plants and reducing the
insect population.
• Split application of neem cake, in addition to FYM,
Azospirillum, Phosphobacterium, SSB, lignite fly ash and
neem cake applied in four splits were found to be effective
in reducing the incidence of major insects. 28

• Application of Azospirillum and phosphobacterium with FYM,
SSB and lignite fly ash FYM increased the content of silica and
potassium in plants which induced resistance in plants.
• Plants imposed with treatments including neem cake (NC),farm
yard manure (FYM), Azospirillum (Azos), Phosphobacterium
(Phos), Silicate Solublising Bacteria (SSB) and lignite fly
ash(LFA).The results revealed that the combination of FYM,
three biofertilizers, lignite fly ash and neem cake applied in
splits significantly reduced the incidence leaf folder (76.69%),
stem borer (58.66 ) and gall midge (66.81%) as compared to NPK
applied as inorganic form.
(P. Chandramani et al.,2013)
29

ELICITORS OF ABIOTIC ORIGIN
30

CHEMICAL ELICITORS
• JA is generally regarded as a key component of the signalling pathway
involved with induced plant resistance to insects with chewing
mouthparts, such as caterpillars. Synthetic analogues of jasmonates
are more potent elicitors of plant responses associated with the JA
pathway than are naturally occurring compounds (Schuler et al.,
2001).
• The JA pathway appears to be involved in induced responses caused
by wounding or by chewing herbivores . Plants sprayed with JA at
1mM had approximately half as many larvae of rice water weevil,
Lissorhoptrus oryzophilus (Coleoptera: Curculionidae),as untreated
controls in trials in North America (M.J. Stout, unpublished).
• Similarly, relative growth rates of S. frugiperda caterpillars were
reduced by the application of 0.5mM JA (M.J. Stout, unpublished).
31

32
JASMONIC ACID SYNTHESIS-
https://www.researchgate.net

33
Mechanism of JA in response to insect attack

34

Effect of induced resistance by JA on
adult female N. lugens (A- Control,
B-2.5 mM JA, C-5 mM JA).
Effect of induced resistance by
JA on N. lugens egg (A-
Control, B-2.5 mM JA, C-5 mM
JA). S.Nathan et al.,2010
35

36

FERTILIZERS
• Various fertilizers and growth stimulants have been
reported to also induce plant resistance to insects.
• For example, several zinc or iron based soil additives have
the additional effects of reducing insect populations. Rice
plants receiving applications of these fertilizers had
approximately half the populations of white backed
planthoppers as untreated controls and produced higher
grain yields (Rath & Misra, 1998) 37

APPLICATION OF CHELATED COMPOUNDS-
Chelated metal complexes act in two ways on the physiology of plants to enhance
crop yields—
By inducing resistance to insect pests and
By acting as plant nutrients.
• Plants sprayed with metal chelates of B and Zn were taller than the others,
perhaps because of the positive role of these metals in the biosynthesis of
auxins.
• Moreover, boron is specifically involved as a catalyst in the rice-plant system
and also as a regulator of important physiological functions such as of many
enzymatic reactions in rice and it is closely involved in nitrogen metabolism .
• Manganese is an activator of several types of plant enzymes such as oxidases,
peroxidases, dehydrogenases, decarboxylases and kinases. It is also involved in
many oxidation-reduction processes (De Datta, 1981) 38

CASE STUDY -K. S. PREMILA AND D. DALE
(1983)
• CHELATED COMPOUNDS & GALL MIDGE-
• They used two chelating agents--Na2EDTA and OTC (
oxytetracycline).
• The possible mode of action of NazEDTA in plants as well as in insect
by its slow release after the cleavage of the metal ion which is used for
physiological functions in the biological system (Neurath, 1970). The
Na2EDTA moiety is apparently taken up by the insects and causes
antibiosis by chelation of metallo-enzymes.
39

• The other chelating agent OTC is a well-known antibiotic.
The direct toxicity of antibiotics to living organisms is well
established.
• Cambell and Birt(1973) have reported that antibiotics could
act as metabolic inhibitors .
• The ash contents of treated plants differed significantly. A
high ash content has been suggested as the basis of the
resistance of rice plants to gall midge (Panda et al., 1975;
Panda, 1979).
40

Silicon
Against YSB-
 A minimum concentration of 3-5% Si in tissue level
needed for pest control in rice. (Datnoff et al., 1997)
 Si uptake by rice plant caused strengthening of the
cell wall which is responsible for the anti lodging
effect in rice ( Painter 1951)
 Si cause culm wall thickening & increase in size of
vascular bundles & hence improving stem rigidity.
(Shimoyama, 1958)
42

 Si also cause cell wall thickening in sclerenchyma &
strengthening of the internodes, thus improve mechanical
strength of rice plants. ( Lee et al., 1990)
 Application of Si reduces the stem diameter which lowered
the stem borer infestation. ( Saeb & Oskou, 2004)
 Addition of Si lead to a reduction in damage in rice due to
YSB which is attributable to a lower preference as well as
digestibility of the leaves & straw by YSB Larvae owing to
the presence of higher Si content ( Ranganathan et al.,
2006)
43

• Combined influence of lignin and cellulose, with silica deposits on cell
wall strengthened the rice stem resulting in development of resistance
against YSB showing non-preference mechanism (Bandong and
Litsinger, 2005).
• Panda et al. have reported that the larvae of yellow stem borer were
unable to attack a resistant rice accession due to higher uptake of
silica in their stems.
• Reduction in stem borer damage due to silicon uptake was attributed
to failure in penetration of neonate larvae ( Tripathy S.,2015)
• Silicon is one such abiotic elicitor which improves the resistance of
rice plant through jasmonic acid synthesis.
44

45
Sclerenchyma and Bundle Sheath thickening in Rice
www.researchgate.net

• Si AGAINST PLANT HOPPERS-
• High level of silicon (400 mg/l) application in rice decreased the food
intake, growth longevity, fecundity and population growth of white
backed plant hopper, Sogatella furcifera as reported by Salim and
Saxena (1992)
• High silica concentration (240 mg/l SiO2) in plant lowered fertility of
hoppers as marked in case of BPH under hydroponic culture. A
reduction in excretion of honeydew was also marked, as that of
control. The result revealed that silicon is one of the main factors that
restrict BPH performance in rice-BPH interactions and it is
potentially of great benefit for non-pesticide BPH management (He et
al., 2015). 46

• Yang et al. (2017) studied the behaviour of BPH in response
to silicon addition to rice plants. An extension of non-
probing event and phloem puncture was clearly marked.
Success rate and duration of phloem ingestion also
decreased significantly. High silicon addition rate (0.32g per
kg of soil) prolonged stylet pathway and time needed to
reach the first phloem puncture.
47

EFFECT OF SILICON ON LEAF FOLDER:
• According to Han et al. (2016) silicon may be involved in
plant physiological or metabolic processes that regulate the
production and accumulation of secondary metabolic
compounds which influence the protective and detoxification
enzyme activity of leaf folder larvae, ultimately affecting
larval survival on rice.
48

Silicon mediated induced resistance to insect pests. (PPO) polyphenol
oxidase, (PAL) phenylalanine ammonia lyase, (HIPVs) herbivore-induced plant volatiles, (JA)
jasmonate phytohormone.( F. Alhousari et al.,2018)
49

ZINC
• Induced resistance has tremendous potential in plants’ defence
mechanism. Biotic and abiotic elicitors trigger a cascade of
pathways favouring production of a number of defensive chemicals
which check the further invasion of the pest.
• Zinc is one such micronutrient which is reported to produce
induced defence mechanism in rice against the sucking pests .
Application of zinc triggers the formation of various secondary
metabolites along with several antioxidative enzymes, which is
helpful in inducing resistance against the insect.
( Tripathy S. And Rath
L.K.,2018)
50

• Zinc exercised a possible induced non-preference
mechanism of resistance in rice to WBPH.
• zinc in form of its sulphatic and EDTA formulations,
applied as basal or foliar spray alone or in various
combinations, against the white backed plant hopper
(WBPH), Sogatella furcifera (Horvath), a major insect
pest on rice, induce resistance against it.
51
( Tripathy S. And Rath L.K.,2018)

Departmental Works
 Silicon induced resistance expression in rice to Yellow stem borer
 Seema Tripathy ,2015
 Advisor- Ladu Kishore Rath
 Crop-Rice
 Variety-Swarna
 Treatment-9
 Replication-3
 Design-RBD
 Concerned Pest-YSB
 Location- field at Central Research Farm, Department of Entomology, OUAT
53

Treatments DEAD HEART % Mean
dead
heart
(%)
Mean
white ear
head (%)
Tunnel length (cm)
at
15DAT 22DAT 29 DAT 36 DAT 43 DAT 50 DAT 57 DAT Maximum
Dead heart
Maximum
white ear
head
Orthosilicic acid @ 2ml/l 0.00
(0.71)
0.33
(0.88)
0.41
(0.91)
1.92
(1.54)
4.07
(2.13)
3.61
(2.03)
2.31
(1.68)
1.81
(1.41)
4.05
(2.13)
5.11
(2.36)
4.39
(2.21)
Orthosilicic acid @ 4ml/l 0.00
(0.71)
0.75
(1.09)
0.83
(1.12)
1.47
(1.39)
3.05
(1.87)
2.88
(1.84)
1.60
(1.44)
1.51
(1.35)
3.33
(1.95)
4.87
(2.30)
4.33
(2.20)
Calcium silicate @ 0.5t/ha 0.00
(0.71)
0.38
(0.90)
0.37
(0.90)
2.11
(1.62)
4.58
(2.25)
3.26
(1.93)
2.41
(1.70)
1.87
(1.43)
4.52
(2.24)
5.92
(2.52)
4.83
(2.31)
Calcium silicate @ 1t/ha 0.00
(0.71)
0.78
(1.10)
1.10
(1.27)
1.91
(1.54)
4.43
(2.21)
2.83
(1.85)
2.12
(1.61)
1.88
(1.46)
4.21
(2.15)
6.03
(2.55)
4.67
(2.27)
Fly ash @ 250kg/ha 0.00
(0.71)
1.05
(1.24)
1.12
(1.27)
2.70
(1.78)
3.95
(2.10)
3.06
(1.88)
2.39
(1.70)
2.04
(1.52)
5.82
(2.49)
7.42
(2.81)
7.10
(2.75)
Fly ash @ 500kg/ha 0.00
(0.71)
1.03
(1.23)
0.75
(1.09)
2.55
(1.74)
3.69
(2.04)
3.33
(1.92)
2.00
(1.57)
1.91
(1.47)
4.82
(2.28)
6.92
(2.72)
6.57
(2.66)
Steel slag @ 250kg/ha 0.00
(0.71)
0.33
(0.88)
0.74
(1.08)
3.15
(1.91)
4.43
(2.22)
3.79
(2.07)
3.32
(1.95)
2.25
(1.54)
7.46
(2.81)
7.23
(2.77)
5.37
(2.42)
Steel slag @ 500kg/ha 0.00
(0.71)
0.86
(1.13)
1.13
(1.28)
2.61
(1.76)
4.37
(2.21)
3.38
(1.96)
2.50
(1.73)
2.12
(1.55)
5.28
(2.39)
6.87
(2.70)
5.03
(2.35)
Control 0.00
(0.71)
1.81
(1.52)
2.79
(1.76)
7.69
(2.89)
10.48
(3.3)
7.56
(2.83)
4.71
(2.27)
5.00
(2.18)
11.44
(3.45)
12.60
(3.61)
18.70
(4.38)
SEm(±) C.D.(0.05) 0.00 0.16 0.17 0.10 0.10 0.13 0.09 - 0.18 0.17 0.0954
Incidence of YSB

NON-PREFERENCE MECHANISM OF INDUCED
RESISTANCE IN RICE TO WHITE BACKED PLANT
HOPPER THROUGH APPLICATION OF ZINC
 Seema Tripathy ,2018
 Advisor- Ladu Kishore Rath
 Crop-Rice
 Variety-TN-1
 Treatment-9
 Replication-3
 Design-CRBD
 Concerned Pest-WBPH
 Location- green house of the Department of Entomology, College of Agriculture,
Odisha University of Agriculture and Technology, Bhubaneswar.
55

Treatments Nymphal alightment at different hours after
release* (%)
Adults (female) alightment at different hours after
release* (%)
6 hour 24 hour 48 hour 72 hour Mean 6 hour 24 hour 48 hour 72 hour Mean
T1: ZnSO4 basal (25kg/ha) 7.68 8.11 8.16 8.25 8.05 9.38 10.09 11.15 11.21 10.46
T2: Zn EDTA basal (40 kg/ha) 7.96 8.23 9.32 9.53 8.76 9.73 10.53 11.03 11.32 10.65
T3: ZnSO4 foliar spray @ 0.5% (5g/l of
water) twice at 30 and 45 DAT
6.33 7.59 8.21 8.47 7.65 8.25 9.27 9.76 10.12 9.35
T4: Zn EDTA Foliar spray @ 0.8% (8g/l of
6.15 7.36 8.67 8.72 7.73 8.17 9.02 9.59 10.19 9.24
T5: ZnSO4 basal (25kg/ha) + ZnSO4 foliar
spray @ 0.5% (5g/l of water) twice at 30
and 45 DAT
5.21 6.91 7.24 7.44 6.70 7.32 8.13 8.38 8.95 8.20
T6: Zn EDTA basal (40 kg/ha)+ Zn EDTA
Foliar spray@ 0.8% (8 g/l of water)twice
at 30 and 45 DAT
4.02 5.33 6.02 6.07 5.36 5.13 5.85 6.12 7.10 6.05
T7: ZnSO4 basal(25kg/ha)+ Zn EDTA Foliar
spray @ 0.8% (8 g/l of water) twice at 30
and 45 DAT
4.32 5.48 6.46 6.62 5.72 6.51 7.04 7.32 7.16 7.01
T8: Zn EDTA basal (40 kg/ha) + ZnSO4
foliar spray @ 0.5% (5g/l of water) twice
at 30 and 45 DAT
5.14 6.03 7.11 7.32 6.40 7.09 7.88 8.42 8.09 7.87
T9: Control 10.32 13.25 15.89 19.75 14.80 13.06 14.01 17.26 18.23 15.64
SEm(±) 0.282 0.276 0.311 0.379 - 0.251 0.228 0.247 0.481 -
C.D.(0.05) 0.84 0.83 0.93 1.14 - 0.75 0.68 0.74 1.44 -
Effect of zinc on WBPH nymphal and adults (female)alightment on rice
56

T1: ZnSO4 basal (25kg/ha) 61.20 22.30
T2: Zn EDTA basal (40 kg/ha) 59.60 22.10
T3: ZnSO4 foliar spray @ 0.5% (5g/l of
58.90 23.20
T4: Zn EDTA Foliar spray @ 0.8% (8g/l of
55.50 23.60
T5: ZnSO4 basal (25kg/ha) + ZnSO4
at 30 and 45 DAT
46.80 25.90
T6: Zn EDTA basal (40 kg/ha)+ Zn EDTA
Foliar spray@ 0.8% (8 g/l of water)twice
at 30 and 45 DAT
34.40 31.68
T7: ZnSO4 basal(25kg/ha)+ Zn EDTA
Foliar spray @ 0.8% (8 g/l of water) twice
at 30 and 45 DAT
38.70 28.35
T8: Zn EDTA basal (40 kg/ha) + ZnSO4
at 30 and 45 DAT
45.40 26.77
T9: Control 86.20 8.80
SEm(±) 0.542 0.303
C.D.(0.05) 1.56 0.87
Effect of zinc on oviposition by WBPH females on
riceTreatments Number of eggs laid* Unhatched eggs* (%)
57

RESULTS-
• Application of Zn in various forms either to soil or plants has caused
uptake of zinc by the rice plants which ultimately might have a
physiological change in the treated rice plants. As a result of which
there was reduced nymphal and female adult attraction to treated
plants as compared to control.
• It was evidenced that the treatment T6 (basal application of Zn EDTA
@ 40 kg/ha along with its foliar spray @ 0.8%, twice at 30 and 45 days
after transplanting) was the most superior treatment in enhancing
the level of non-preference in the treated rice plants as compared to
untreated plants.
58

IMPACT OF DIATOMACEOUS EARTH ALONE AND IN COMBINATION
WITH NEWER INSECTICIDES ON MAJOR INSECT PESTS OF RICE
WITH SPECIAL REFERENCE TO
STEM BORER
 Surabhika Panda ,2018
 Advisor- Ladu Kishore Rath
 Crop-Rice
 Variety-TN-1
 Treatment-10
 Replication-3
 Design-RBD
 Concerned Pest- YSB, LEAF FOLDER,BPH,WBPH
 Location- Central Research Farm, O.U.A.T. 59

60
Field efficacy of different doses of DAE against yellow stem borer in rice

61
Population of planthoppers in rice as influenced by graded doses of DAE

62
Effect of differential doses of DAE on leaf folder infestation in rice

GENETIC TECHNIQUES TO INCORPORATE
INDUCED RESISTANCE
• Classical breeding programmes for plant resistance to diseases and
herbivores have been limited by the existing heritable variation present in
the species (or closely related species). Genetic engineering offers the
exciting possibility of incorporating novel resistance traits from other
species, families, and even phyla into rice varieties that show desirable
traits.
• For example, rice varieties in China have been transformed using
Agrobacterium to incorporate inducible cowpea trypsin inhibitors. These
transformed plants showed enhanced resistance against stem borers.
• Transformed plants supported smaller populations of several caterpillars
including stem borers and rice leaf folders and reduced levels of damage
compared to untransformed controls in field trials .
https://royalsociety.org/topics-policy/projects/gm-plants/what-is-gm-and-how-is-it
64

• Biotechnological approaches require that traits providing induced
resistance be identified, the genes controlling them must be mapped,
and techniques for transferring them into desirable varieties be
developed.
• Since biotechnological approaches can be extremely specific, they can
theoretically provide greater safety in terms of minimizing
environmental problems and undesirable secondary chemicals
associated with inducers of more generalized plant responses.
• Additional control over expression of resistance traits may be possible
if genes can be fused to inducible promoters so that the desired
products can be switched on and off as needed.
65

CONCLUSION
• Induced resistance is an excellent system in which to allow
early season pests to induce resistance against later ones.
• Rice varieties have been identified that have high levels of
Induced resistance against the rice gall midge and against
white and brown planthoppers. Since the rice genome is so
well characterized, this mechanism has a great future in
plant protection aspect.
66

• Early attack by economically unimportant species may also
provide resistance against more damaging species of rice insects.
For example, leaf folders are common early season feeders. rice
leaf folder is easy to identify in the field, it has a wide natural
distribution, and it can be easily introduced & they have the
potential to help protect plants against more costly species.
• Chemical elicitors of induced resistance may also allow rice
farmers to manipulate the levels and timing of plant resistance.
Several of the economically important rice pests have been found
to be affected by host plant resistance that is mediated by plant
hormones such as JA
67

FACTORS INDUCING RESISTANCE AGAINST INSECT PEST OF RICE

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