Contents - Faperta

Evaluation of Transgenic Plants and Mapping Populations for Resistance to Insect Pests 57
FIGURE 3.8 Detached leaf assay to screen for resistance to insect pests. (A) Uninfested leaves of cotton, chickpea,
pigeonpea, and groundnut. (B), (C), and (D) are reactions of pigeonpea, chickpea, and cotton to neonate
larvae of Helicoverpa armigera using detached leaf assay.
The detached leaves are infested with neonate or third-instar larvae, nymphs, or adults.
The test is easy and quick, and can be carried out with different parts of the same plant
at different growth stages without sacrifi cing the plant. The reactions of test genotypes
invariably are similar to those under natural infestation (Figure 3.9). However, excision
of plant parts at times leads to a change in the physico-chemical properties of the plants,
and the magnitude of resistance can either decrease (Thomas, Sorensen, and Painter,
(A) (B)
Damage Rating
9
8
7
6
5
4
3
2
1
0
ICC 506 Annigeri ICCC 37I CC 3137
Genotype
Field DLA
(C) 6
(D)
7
Damage Rating
5
4
3
2
1
0
NCAc 343 Robut 33-1 ICGV 86031 FDRS 10 TMV 2
Genotype
Field DLA
10
9
8
7
6
5
4
3
2
1
0
ICPL 84060 ICP 187-1 ICPL 332 ICP 7203-1 ICPL 87
Genotype
Field DLA
FIGURE 3.9 Expression of resistance to Helicoverpa armigera in different genotypes of (A) chickpea, (B) pigeonpea,
(C) groundnut, and (D) cotton in detached leaf assay (DLA) and under natural infestation in the fi eld.
Damage Rating
Damage Rating
6
5
4
3
2
1
0
MECH 162 Aravinda Non MECH 162 L 604
Leaf Damage Rating Boll Damage