Wild Relatives of Crops as Sources of Genes for Resistance to Insect Pests

Nov 2009

Levels of resistance to insect pests in cultivated germplasm are quite low, and therefore, the need to explore resistance genes from wild relatives of crops to diversify the basis of resistance to insect pests. We evaluated wild relatives of pigeonpea for resistance to pod borer, Helicoverpa armigera, pod fly, Melanagromyza obtusa and pod wasp, Tanaostigmodes cajaninae; chickpea wild relatives for resistance to pod borer, H. armigera; Arachis wild relatives for resistance to leaf miner, Aproaerema modicella, leafhopper, Empoasca kerri, leaf feeding caterpillars, H. armigera and Spodoptera litura; and sorghum wild relatives for resistance to shoot fly, Atherigona soccata, stem borer, Chilo partellus, and sorghum midge, Stenodiplosis sorghicola.

Evaluation of wild relatives of pigeonpea for resistance to insects• Accessions belonging to Cajanus

scarabaeoides, C. sericeus andC. acutifolius showed high levels of resistance to H. armigera.

• High levels of antibiosis were observed in C. sericeus (ICPW 159) and C. scarabaeoides (ICPW 125, and ICPW 152) (Table 1).

• The larvae took 32.7 to 42.5 days to complete development on C. scarabaeoides compared to 21.7 days on ICPL 87. ICPW 141, ICPW 278 and ICPW 280 (C. scarabaeoides), ICPW 14(C. albicans) and F. stricta (ICPW 202) showed resistance to both pod fly and pod wasp.

Table 1. Survival and development of Helicoverpa armigera on wild relatives of pigeonpea

Accession Species

Larval weight (mg)

Larval mortality

(%) Larval period (days)15 days 20 days

ICPW 1 C. acutifolius 154.5 62 25.4

ICPW 159 C. sericeus 112.1 58 22.7

ICPW 125 C. scarabaeoides 46.4 62 33.7

ICPW 152 C. scarabaeoides 112.1 48 36.1

ICPL 332 - R C. cajan 294.5 46 24.3

ICPL 87 - S C. cajan 325.2 36 21.7

SE ± 6.0 6 1.63

Table 2. Survival and development of Spodoptera litura on wild relatives of groundnut.

Accession Species

Leaf feeding

(DR)

Larval weight (mg)

Larval survival

(%)

ICG 8201 A. duranensis 4.3 31.5 70.0

ICG 8190 A. hoehnei 5.3 18.5 53.3

ICG 8206 A. ipaensis 2.7 10.0 46.7

ICG 8945 A. appressipila 2.7 12.6 60.0

ICGV 86699 A. hypogaea - R 9.0 68.5 80.0

TMV 2 A. hypogaea - S 7.0 100.1 56.7

SE ± 0.8 8.2 9.5

DR = Damage rating (1 = < 10%, and 9 = > 80% leaf area damaged)

Evaluation of wild relatives of sorghum for resistance to insects• Accessions belonging to

Parasorghum (Sorghum australiense, S. versicolor andS. nitidum) and Stiposorghum(S. angustum, S. intrans andS. stipodeum) did not show any shoot fly damage under field conditions (Table 3).

• Species belonging to Heterosorghum (S. laxiflorum), Parasorghum (S. australiense,S. purpureosericeum, S. versicolor and S. nitidum), and Stiposorghum (S. angustum, S. intrans and S. stipoideum) suffered little damage by stem borer (Table 4).

• Sorghum amplum, S. bulbosum, and S. angustum have shown high levels of resistance to sorghum midge. Many accessions of the wild relatives of sorghum showed high levels of antibiosis to shoot fly and stem borer, while the resistance in the cultivated germplasm is largely based on oviposition non-preference.

Table 3. Deadheart incidence and adult emergence of Atherigona soccata on wild relatives of sorghum.

Section Species Accession

Deadhearts (%) Adult emergence

(%)Field No-choice

Chaetosorghum S. macrospoermum TRC 24112 6.7 61.5 -

Heterosorghum S. laxiflorum IS 18958 0.0 7.4 6.2

Parasorghum S. australiense IS 18954 0.0 10.1 4.2

Stiposorghum S. angustum TRC 243499 0.0 4.0 0.0

Sorghum S. ethiopicum IS 27584 88.9 - 99.5

S. bicolor IS 18551 - R 30.6 93.6 50.8

ICSV 1 - S 96.7 98.4 79.4

SE ± 8.3 19.6 -

Table 4. Deadheart incidence and survival of Chilo partellus larvae on wild sorghums.

Section Species Accession

Deadhearts (%) Larval survival

(%)Field No-choice

Heterosorghum S. laxiflorum IS 18958 0.0 82.5 6

Parasorghum S. australiense IS 18954 0.0 10.5 0

Stiposorghum S. angustum TRC 243499 0.0 0.0 6

S. virgatum IS 18808 94.5 98.2 55

S. bicolor IS 2205 - R 58.0 96.8 40

CSH1 - S 95.5 98.4 90

SE ± 8.3 82.5 6

C. sericeus C. scarabaeoides

Wild relatives of pigeonpea.

C. bijugumC. reticulatum

0102030405060708090

100

IG 6

99

48

IG 7

00

32

IG 7

00

33

IG 7

29

31

IG 7

00

39

IG 7

00

02

IG 7

00

10

IG 6

99

47

IG 6

99

80

IG 7

00

19

IG 7

00

03

IG 6

99

79

ICC

50

6

Annig

eri

ICC

C 3

7

Accessions

La

rva

l w

eig

ht

(mg

) Wt. (mg) 10 DAR

C. arietinum

C.

pin

natifid

um

C. ju

daic

um

C. ju

daic

um

C. ju

daic

um

C.

pin

natifid

um

C. b

ijug

um

C. b

ijug

um

C. b

ijug

um

C. ju

da

icum

C. b

ijug

um

C. b

ijug

um

C.

cu

nea

tum

Figure 1. Weights of Helicoverpa armigera larvae at 10 days after release on wild relatives of chickpea.

Evaluation of wild relatives of chickpea for resistance to Helicoverpa• Accessions IG 72933, IG 72934

and IG 72953 (Cicer reticulatum), ICC 17257 and IG 70012 (C. bijugum), IG 69979 (C. cuneatum), and IG 70032 and IG 72931 (C. judaicum) showed lower leaf feeding and a drastic reduction in larval weight.

• Weights of 10-day old larvae ranged from 11.72 to 26.66 mg on the wild relatives compared to 46.48 mg on ICC 506, and 80.94 mg on ICCC 37) (Fig. 1). Wild relatives of chickpea.

Wild relatives of groundnut.

Wild relatives of sorghum.

A. cardenasii A. valida

A. diogoi

S. nitidum arare

S. australiense

Conclusions• Considerable progress has

been made in identification of resistance in wild relatives to Helicoverpa in pigeonpea and chickpea; Atherigona, Chilo and Stenodiplosis in sorghum; and Empoasca, Aproaerema and Spodoptera in groundnut.

• Information has been generated on the physico-chemical mechanisms conferring resistance to the target insects. Some of these mechanisms are different from those found in the cultivated germplasm.

• Genes from wild relatives can be tapped through wide hybridization and marker assisted selection to diversify the bases of resistance to insect pests for sustainable crop production.

Acknowledgments: The financial support provided by DFID, UK; GRDC, Australia; USAID – CGIAR Linkage Grant, USA; and Andhra Pradesh Netherlands Project on Biotechnology, is gratefully acknowledged.

For more information contact: HC Sharma, Principal Scientist (Entomology), e-mail: h.sharma@cgiar.org

Evaluation of wild relatives of groundnut for resistance to insects• Accessions belonging to

Arachis cardenasii, A. duranensis andA. triseminata showed multiple resistance to leaf miner, A. modicella, defoliators,H. armigera and S. litura and the leafhopper, E. kerri.

• Arachis cardenasii (IGG 8216) and A. appressipila (ICG 8946) showed high levels of antibiosis to S. litura (Table 2).

HC Sharma1, G Sujana1, V Kamala1, G Pampapathy1, PC Stevenson2, TJ Ridsdill-Smith3, and S L. Clement4

1International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru 502 324, Andhra Pradesh, India. 2Natural Resources Institute (NRI), Maritime, Chatham, Kent, UK. 3Commonwealth Scientific and Industrial Research Organization (CSIRO), Entomology, Wembley 6913, Western Australia,

Australia. 4USDA, ARS Plant Germplasm Introduction and Testing Research Unit, Washington State University, Pullman, WA 99164-6402, USA.