Antixenosis and antibiosis mechanisms of resistance in chickpea germplasm against gram pod borer, Helicoverpa armigera (Hübner)

Introduction

Chickpea (Cicer arietinum L.), commonly known as Bengal gram, is the most important pulse crop grown during the rabi season in India, contributing nearly 45 per cent of the country's total pulse production and serving as a major source of dietary protein (20-22%), carbohydrates and essential minerals, particularly for the vegetarian population (Jukanti et al., 2012; Merga et al., 2019) [1,2] . Globally, chickpea is cultivated on about 14.5 million hectares with an annual production of approximately 16.0 million tonnes, while India alone accounts for about 10.1 million hectares and 11.6 million tonnes of production (FAO, 2024; NITI Aayog, 2025) [3,4] . In Chhattisgarh, chickpea is predominantly grown after rice under residual soil moisture over 0.15-0.20 million hectares, with the crop concentrated in the districts of Bemetara, Kabirdham, Rajnandgaon, Durg and Balod (Directorate of Agriculture et al., 2025; Directorate of Economics and Statistics, 2025) [5,6] . Chickpea productivity is severely constrained by insect pests, of which the gram pod borer, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is the most destructive and economically important field pest across major chickpea-growing regions of the world (Sharma et al., 2007) [7] . This highly polyphagous, multivoltine and cosmopolitan insect feeds on more than 180 plant species and its larvae bore into pods and consume developing seeds, causing yield losses ranging from 20 to 95 per cent depending on germplasm, crop stage and pest pressure (Pawar, 1998; Sharma, 2005; Randhawa et al., 2025) [8,9,10] . Excessive and repeated use of chemical insecticides against H. armigera has led to resurgence of the pest, insecticide resistance and adverse effects on natural enemies and the environment. Under such circumstances, host plant resistance (HPR) is considered one of the most economical, durable and environmentally compatible components of integrated pest management. Resistance may operate through antixenosis (non-preference), antibiosis or tolerance mechanisms (Painter, 1951) [11] . Morphological and physio-morphological traits such as plant growth habit, trichome type, trichome length and density, pod wall thickness and pod size are important components of antixenosis, reducing insect preference, oviposition and larval establishment (Shabbir et al., 2014; Hossain et al., 2008) [13,12] . In addition, biochemical constituents such as phenols, flavonoids, tannins, sugars and organic acids influence larval feeding, growth and survival, thereby contributing to antibiosis resistance (Sharma et al., 2005; Golla et al., 2020; Sane et al., 2025) [15,14,16] . Germplasm possessing favourable morphological and biochemical characteristics generally exhibits lower larval establishment and reduced pod damage, and the identification and utilisation of such resistant germplasm can reduce dependence on chemical insecticides while conserving natural enemies (Rehman et al., 2024; Sharma et al., 2020) [17,18] . Although extensive work has been carried out on individual morphological or biochemical traits associated with resistance in chickpea, an integrated field-cum-laboratory assessment of both antixenosis and antibiosis mechanisms within the same set of germplasm under the agro-climatic conditions of Chhattisgarh has received comparatively limited attention. Keeping this in view, the present investigation was undertaken to evaluate (i) the antixenosis resistance of chickpea germplasm based on morphological and physio-morphological traits, and (ii) the antibiosis resistance based on biochemical constituents, against gram pod borer, H. armigera, with the objective of identifying promising donor sources for utilisation in resistance-breeding programmes.

Materials and methods

Experimental site

Field experiments were conducted at the Research-cum-Instructional Farm, College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya (IGKV), Raipur, Chhattisgarh, during rabi 2025-26, while biochemical analyses were carried out in the laboratory of the Department of Entomology. Raipur is located in the mid-eastern part of Chhattisgarh at 21°16'N latitude, 81°36'E longitude and at an elevation of 289.56 m above mean sea level.

Experimental material

A total of 37 chickpea germplasms, including the resistant check L550 and the susceptible check JG315, were selected based on their agronomic importance, availability and expected variability in reaction to H. armigera (Table 1). The crop was raised in a Randomized Block Design with two replications, in single rows of 3 m length with 3 m × 3 m plot size and 30 cm × 10 cm spacing. The crop was sown on 3 December 2025 and harvested on 18 March 2026, following the recommended package of practices for chickpea cultivation.

Evaluation of antixenosis resistance

Plant type was recorded visually and genotypes were classified as erect, semi-erect or spreading based on growth habit and branching pattern (Rahman et al., 2000) [19] . Trichome type (glandular and nonglandular) was determined by preparing epidermal mounts of leaf and pod samples and examining them under a compound microscope (Shabbir et al., 2014) [13] . For trichome length and density, uniformly developed leaf and pod samples were cleared in acetic acid-alcohol (2:1) and mounted in 90% lactic acid, and trichomes were measured and counted under a stereo microscope at 40× magnification, density being expressed as number of trichomes mm -2 . Pod wall thickness was measured using a digital Vernier caliper on hand-cut cross-sections at four points on five pods per entry (Hossain et al., 2008) [12] , and pod length and pod width were similarly measured on representative pods. Arrangement of seeds within the pod was recorded visually on mature pods (Van der Maesen, 1987) [20] . Larval population of H. armigera was recorded on ten randomly selected plants per germplasm per replication at the vegetative, 50% flowering and 50% pod maturity stages, and per cent pod damage was worked out at harvest as:

Pod damage (%)= ( Number of damaged pods/Total number of pods ) × 100

Evaluation of antibiosis resistance

On the basis of field reaction and the Pest Resistance Susceptibility Rating (PRSR) scale (Reed et al., 1980) [21] , fifteen chickpea germplasms representing contrasting levels of resistance and susceptibility were selected from the 37 germplasms for biochemical analysis. Total phenol content was estimated by the Folin-Ciocalteu method (Malick et al., 1980) [22] , with absorbance recorded at 650 nm against a catechol standard. Total soluble sugar content was measured using a hand refractometer and expressed in °Brix (Srivastava et al., 1994) [23] . Total flavonoid content was estimated by the aluminium chloride colorimetric method using quercetin as the reference standard, with absorbance recorded at 510 nm (Zhishen et al., 1999) [24] . Malic acid content was determined by titrating leaf washings against 0.01 N NaOH using phenolphthalein as indicator (Rembold, 1981) [25] . Tannin content was estimated by the vanillin-hydrochloride method using catechin as the standard, with absorbance measured at 500 nm (Burns, 1971) [26] .

Statistical analysis

The larval population data were subjected to square-root transformation ( √ 𝑥 + 0.5) and the pod damage percentage data were arcsinetransformed prior to analysis of variance under the Randomized Block Design (Gomez et al., 1984) [27] . Simple correlation coefficients (r) were worked out between larval population and each of the antixenosis and antibiosis characters, and their significance was tested by the t-test at n-2 degrees of freedom. Standard error, critical difference (5%) and coefficient of variation were computed following standard statistical procedures.

RC-Resistant check, SC-susceptible check

Results and discussion

Antixenosis resistance in chickpea germplasm

Plant type

The 37 chickpea germplasms exhibited variation in growth habit and were classified into erect, semi-erect and spreading types based on plant architecture. Erect genotypes generally recorded lower larval infestation and pod damage than spreading types, probably due to differences in canopy structure that influence oviposition sites and larval movement. These findings agree with Yadav et al. (2006) [28] and Sharma et al. (2018) [29] , who reported that spreading chickpea genotypes suffered greater H. armigera infestation than erect, compact types, and with Sane et al. (2025) [16] , who identified erect plant type and compact canopy among the morphological traits associated with reduced oviposition and larval establishment.

Trichome length on leaf and pod

Glandular trichome length on leaves ranged from 0.10 to 0.29 mm, with the highest recorded in Phule G-1705-2-9 (0.29 mm) and the lowest in GNG-2701, COC 1902 and JG315 (0.10 mm); this trait showed a significant negative correlation with larval population (r = -0.357*). Non-glandular trichome length on leaves ranged from 0.08 to 0.28 mm, being highest in GJG 2306 and L550 (0.28 mm) and lowest in RVSS G 139 (0.08 mm), with a highly significant negative correlation (r = -0.541**). On pods, glandular trichome length ranged from 0.10 to 0.27 mm (r = -0.371*) and non-glandular trichome length ranged from 0.17 to 0.28 mm (r = -0.354*), both being negatively associated with larval population (Table 2, Table 3). These results are in agreement with Shabbir et al. (2014) [13] and Hossain et al. (2008) [12] , who reported that chickpea germplasms possessing longer trichomes recorded comparatively lower pod damage. Longer trichomes may act as a physical barrier that restricts larval movement and feeding, while glandular trichomes may additionally release secondary metabolites or sticky exudates that reduce host acceptance, together contributing to antixenosis resistance.

Trichome density on leaf and pod

Leaf trichome density ranged from 10.50 to 25.50 trichomes mm -2 , with the highest in GJG 2306 (25.50) and the lowest in RVSS G 139 (10.50), and showed a highly significant negative correlation with larval population (r = -0.550**). Pod trichome density ranged from 13.50 to 28.50 trichomes mm -2 , with the highest in L550 (28.50) and the lowest in NBEG 1740 and Phule G-0517 (13.50), and was also highly significantly negatively correlated with larval population (r = -0.577**). Both glandular and non-glandular trichomes were observed on the leaf and pod surfaces of all germplasms, with non-glandular trichomes generally more prominent. These findings are consistent with Johnpeter et al. (1995) [30] , Kanchana et al. (2005) [31] and Noreen et al. (2024) [32] , who all reported that greater trichome density was associated with lower pod damage in chickpea. Higher trichome density may function as an effective physical barrier that interferes with larval movement, feeding and oviposition, thereby making the plant less suitable for H. armigera.

Pod length, pod width and pod wall thickness

Mean pod length varied from 9.30 to 18.85 mm and mean pod width from 6.35 to 10.60 mm among the germplasms, but neither trait showed a significant association with larval population (r = -0.238 NS and r = -0.149 NS , respectively), indicating a limited role of pod size per se in resistance. In contrast, pod wall thickness, which ranged from 0.14 to 0.29 mm, was significantly negatively correlated with larval population (r = -0.411*); the thickest pod walls were recorded in Phule G 1620-7-3 (0.29 mm) and L550 (0.27 mm), and the thinnest in RVSS G 139 (0.14 mm) and JG315 (0.15 mm). This agrees with Hossain et al. (2008) [12] and Lakra et al. (2018) [33] , who reported that thicker pod walls were associated with lower pod damage, suggesting that pod wall thickness provides a mechanical barrier to larval penetration.

Seed arrangement and pod damage

All 37 germplasms exhibited a uniform single-row (uniseriate) arrangement of seeds within the pod, and this character could therefore not differentiate resistant from susceptible reactions. Pod damage caused by H. armigera ranged from 7.00 to 41.00 per cent; the lowest damage was recorded in GJG 2306 (7.00%), L550 (7.20%), IPC 2020-123 (9.40%), RKG 25-10 (11.00%) and Keonjhar chana 2 (13.00%), while the highest was recorded in RVSS G 139 (41.00%), GJG 2210 (35.00%), NBEG 1740 (31.00%), JGK 5 (29.20%) and GJG 2401 (28.80%) (Table 4). On the basis of the PRSR scale, IPC 2020-123 was categorised as resistant (Rating 3) and BDNG 220-61, Phule G 1620-7-3, Phule G-1705-8-20, Keonjhar chana 2 and BG 4078 as moderately resistant (Rating 4), whereas RVSS G 139 was categorised as highly susceptible (Rating 9).

Antibiosis resistance in chickpea germplasm

Based on field reaction and PRSR grading, fifteen chickpea germplasms of contrasting resistance and susceptibility were evaluated for total phenol, total soluble sugar, flavonoid, malic acid and tannin content, and correlated with larval population of H. armigera (Table 5, Table 6).

Total phenol content

Total phenol content ranged from 0.20 to 0.33 mg/g, being highest in BG 4078 and L550 (0.33 mg/g) and lowest in RVSS G 139 (0.20 mg/g). Correlation analysis revealed a highly significant negative association between phenol content and larval population (r = -0.792**), the strongest among all the characters studied, indicating that higher phenol accumulation was associated with greater resistance. These results are in agreement with Sharma et al. (2005) [15] , Kaur et al. (2016) [34] , Golla et al. (2020) [14] and Reddy et al. (2022) [35] , who reported that resistant chickpea germplasms possessed higher phenol content and lower pod damage. Phenolic compounds are oxidised to quinones, which bind with proteins and interfere with larval digestion, thereby reducing larval growth and contributing to antibiosis resistance.

Total soluble sugar content

Total soluble sugar (TSS) content ranged from 3.70 to 7.25 °Brix, being highest in RVSS G 139 (7.25 °Brix) and lowest in L550 (3.70 °Brix). Unlike the other biochemical characters, TSS showed a highly significant positive correlation with larval population (r = 0.664**), indicating that higher sugar content favoured larval feeding and development. This finding is consistent with Kamakshi et al. (2008) [36] and Sane et al. (2025) [16] , who reported that susceptible germplasms generally possess higher sugar levels that enhance pod palatability and nutritional suitability for larval feeding, whereas lower soluble sugar content contributes to antibiosis resistance.

Total flavonoid content

Total flavonoid content ranged from 0.07 to 0.17 mg/g, being highest in L550 (0.17 mg/g) and lowest in JG315 (0.07 mg/g), with a highly significant negative correlation with larval population (r = -0.697**). These results agree with Kaur et al. (2016) [34] , Jaba et al. (2017) [37] and Reddy et al. (2022) [35] , who reported negative associations between flavonoid content and pod damage. Flavonoids may act as antifeedants that impair larval digestion, growth and development, reducing the suitability of pods for H. armigera feeding.

Malic acid content

Malic acid content ranged from 0.70 to 1.48 per cent, being highest in GJG 2306 (1.48%) and lowest in JG315 (0.70%), and showed a significant negative correlation with larval population (r = -0.544*). These results corroborate Lateef (1985) [38] and Yoshida et al. (1995) [39] , who reported that resistant chickpea germplasms contained higher amounts of organic acids in leaf exudates, associated with reduced larval survival and pod damage.

Tannin content

Tannin content ranged from 0.62 to 1.50 mg/g, being highest in L550 (1.50 mg/g) and lowest in JG315 (0.62 mg/g), with a significant negative correlation with larval population (r = -0.572*). These results are supported by Sharma et al. (2014) [40] and Kaur et al. (2016) [34] , who reported that resistant chickpea cultivars possessed higher tannin levels along with reduced insect growth and pod damage, suggesting that tannins interfere with larval feeding and development, thereby contributing to antibiosis resistance.

Conclusions

Evaluation of antixenosis resistance revealed significant variation among 37 chickpea germplasms for trichome length and density on leaves and pods, and for pod wall thickness, all of which were negatively correlated with larval population of H. armigera, whereas pod length and pod width had no significant influence. Germplasms L550, GJG 2306 and IPC 2020-123, possessing longer and denser trichomes and thicker pod walls, recorded the lowest pod damage and can serve as sources of antixenosis resistance. Evaluation of antibiosis resistance among fifteen selected germplasms showed that higher total phenol, flavonoid, malic acid and tannin contents, and lower total soluble sugar content, were associated with reduced larval population, with total phenol showing the strongest association (r = -0.792**). L550, GJG 2306 and BG 4078 exhibited the most favourable biochemical profiles. Germplasms combining favourable antixenosis and antibiosis attributes, particularly L550, GJG 2306 and IPC 2020-123, represent promising donor sources that may be utilised in chickpea breeding programmes aimed at developing H. armigera-resistant cultivars.

Acknowledgement

AcknowledgementThe authors gratefully acknowledge the Department of Entomology, College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh, for providing the field and laboratory facilities necessary to carry out this investigation.

References

1. Jukanti AK, Gaur PM, Gowda CLL, Chibbar RN. Nutritional quality and health benefits of chickpea (Cicer arietinum L.): a review. Br. J. Nutr. 2012;108(S1):S11-S26.
2. Merga B, Haji J. Economic importance of chickpea: Production, value, and world trade. Cogent Food Agric. 2019;5(1):1615718.
3. FAO. FAOSTAT: Production Statistics of Crops and Livestock Products. Food and Agriculture Organization of the United Nations, Rome, Italy; 2024.
4. NITI Aayog. Annual Report 2024-25. New Delhi: Government of India; 2025.
5. Directorate of Economics and Statistics. Area, Production and Yield Statistics of Principal Crops. Department of Agriculture and Farmers Welfare, Government of India; 2025.
6. Sharma HC, Gowda CLL, Stevenson PC, Ridsdill-Smith TJ, Clement SL, Rao GR, El-Bouhssini M. Host plant resistance and insect pest management in chickpea. In: Chickpea Breeding and Management. Wallingford, UK: CABI; 2007:520-537.
7. Pawar VM. Microbial control of Helicoverpa armigera on pulse crops. IPM Systems in Agriculture. New Delhi, India: Aditya Books Private Limited; 1998:55-78.
8. Sharma HC. Heliothis/Helicoverpa Management, Emerging Trends and Strategies for Future Research. New Delhi, India: Oxford and IBH; 2005.
9. Randhawa HS, Kaur C, Singh G, Taggar GK. Impact of chickpea varieties and sowing dates on pod borer Helicoverpa armigera (Hubner). Legume Res. 2025;48(7).
10. Painter RH. Insect Resistance in Crop Plants. New York, USA: Macmillan; 1951.
11. Hossain M, Haque A, Prodhan MZH. Effect of pod characteristics on pod borer, Helicoverpa armigera (Hubner), infestation in chickpea. SAARC J. Agric. 2008;6(1):1-11.
12. Shabbir MZ, Arshad M, Hussain B, Nadeem I, Ali S, Abbasi A, Ali Q. Genotypic response of chickpea (Cicer arietinum L.) for resistance against gram pod borer (Helicoverpa armigera). Adv. Life Sci. 2014;2(1):23-30.
13. Golla SK, Sharma HC, Rajasekhar P, Mishra SP, Jaba J. Biochemical components of wild relatives of chickpea confer resistance to pod borer, Helicoverpa armigera. Arthropod-Plant Interact. 2020;14(5):623-639.
14. Sharma HC, Pampapathy G, Lanka SK, Ridsdill-Smith TJ. Antibiosis mechanism of resistance to pod borer, Helicoverpa armigera in wild relatives of chickpea. Euphytica. 2005;142(1):107-117.
15. Sane Y, El Fakhouri K, Boulamtat R, Sobeh M, El Bouhssini M. Defense mechanisms of chickpea against chickpea pod borer, Helicoverpa armigera and chickpea leafminer, Liriomyza cicerina: from plant morphology to molecular level. ACS Omega. 2025;10(30):32587-32605.
16. Rehman SA, Gul S, Parthiban M, Thudi M, Penmetsa RV, Varshney RK, Mir RR. Genetic resources and genes/QTLs for gram pod borer (Helicoverpa armigera Hübner) resistance in chickpea from the Western Himalayas. Plant Genome. 2024;17(3):e20483.
17. Sharma S, Sharma R. Chickpea economy in India. In: Chickpea: Crop Wild Relatives for Enhancing Genetic Gains. Academic Press; 2020:225-250.
18. Rahman SML, Nawata E, Sakuratami T, Uddin S. Ecological adaptation of chickpea (Cicer arietinum L.) to water stress. Legume Res. 2000;23(3):141-145.
19. Van der Maesen LJG. Origin, history and taxonomy of chickpea. The Chickpea. 1987;11.
20. Reed W, Lateef SS, Sithanantham S. Insect pest management on chickpea. In: Proceedings International Workshop on Chickpea Improvement. 1980:179-183.
21. Malick CP, Singh MB. Plant Enzymology and Histoenzymology. New Delhi: Kalyani Publishers; 1980.
22. Srivastava RP, Kumar S. Fruit and Vegetable Preservation: Principles and Practices. CBS Publishers and Distributors Pvt. Limited; 1994.
23. Zhishen J, Mengcheng T, Jianming W. The determination of flavonoid contents in mulberry and their scavenging effects on superoxide radicals. Food Chem. 1999;64(4):555-559.
24. Rembold H. Malic acid in chickpea exudate-a marker for Heliothis resistance. Int. Chickpea Newsl. 1981;4:18-19.
25. Burns RE. Method for estimation of tannin in grain sorghum. Agron. J. 1971;63(3):511-512.
26. Gomez KA, Gomez AA. Statistical Procedures for Agricultural Research, 2nd ed. John Wiley and Sons, New York, USA; 1984. 680 p.
27. Yadav SS, Kumar J, Yadav SK, Singh S, Yadav VS, Turner NC, Redden R. Evaluation of Helicoverpa armigera and drought resistance in desi and kabuli chickpea. Plant Genet. Resour. 2006;4(3):198-203.
28. Sharma H, Shukla A, Bhowmick AK, Sharma AK. Evaluation of chickpea (Cicer arietinum L.) genotypes against gram pod borer Helicoverpa armigera (Hübner) under field conditions. J. Entomol. Zool. Stud. 2018;6:597-602.
29. Johnpeter A, Shanower TG, Romes J. The role of plant trichomes in insect resistance: a selective review. Phytophaga. 1995;7:4164.
30. Kanchana R, Lakshmi KV, Sekhar PR. Morphological and biochemical bases of host plant resistance to Helicoverpa armigera (Hubner) in chickpea. J. Plant Prot. Environ. 2005;2(1):12-17.
31. Noreen A, Hameed A, Shah TM. Field screening and identification of biochemical indices of pod borer (Helicoverpa armigera) resistance in chickpea mutants. Front. Plant Sci. 2024;15:1335158.
32. Lakra RK, Sahu A, Korat DM, Singh PS. Screening of pigeonpea genotypes against pod borer complex under field conditions. J. Entomol. Zool. Stud. 2018;6(5):1709-1713.
33. Kaur S, Kaur S, Gupta AK, Kaur J. Physiochemical and nutritional attributes of raw and soaked seeds of chickpea (Cicer arietinum L.) genotypes. Legume Res. 2016;39(3).
34. Reddy MS, Agnihotri M, Divija SD, Belal B, Karthik S. Host plant resistance profiling of chickpea genotypes against Helicoverpa armigera (Hübner) through SEM and GC-MS studies. Int. J. Trop. Insect Sci. 2022;42(2):1627-1638.
35. Kamakshi N, Srinivasan S. Influence of certain biophysical factors on incidence of pod borer complex in selected genotypes of field bean. Ann. Plant Prot. Sci. 2008;16(2):407-409.
36. Jaba J, Devrani A, Agnihotri M, Chakravarty S. Screening of chickpea cultivars against pod borer Helicoverpa armigera (Hubner) under unprotected conditions. J. Exp. Zool. India. 2017;20(2):835-843.
37. Lateef SS. Gram pod borer Heliothis armigera (Hubner) resistance in chickpeas. Agric. Ecosyst. Environ. 1985;14(1-2):95102.
38. Yoshida M, Cowgill SE, Wightman JA. Mechanism of resistance to Helicoverpa armigera (Lepidoptera: Noctuidae) in chickpea: role of oxalic acid in leaf exudate as an antibiotic factor. J. Econ. Entomol. 1995;88(6):1783-1786.
39. Sharma Saruchi, Thakur DR. Biochemical basis for bruchid resistance in cowpea, chickpea and soybean genotypes. Am. J. Food Technol. 2014.
40. Brar HS, Singh R. Host plant resistance in chickpea against gram pod borer, Helicoverpa armigera (Hübner) under field and laboratory conditions. J. Food Legumes. 2015;28(1):69-72.
41. Department of Agriculture and Farmers Welfare. Agricultural Statistics at a Glance 2025. Ministry of Agriculture and Farmers Welfare, Government of India; 2025.