Bruchid Resistance Research Articles

A 90-day study of three bruchid-resistant mung bean cultivars in Sprague-Dawley rats

Mung bean has been traditionally and widely used as an edible and medicinal plant in the South and Southeast Asia. Bruchid resistance mung bean has more potential in commercial use, but scarcely been evaluated for safety through standard in vivo toxicological studies. In the present study, subchronic oral toxicity studies of bruchid-resistant mung bean were designed and conducted in Sprague-Dawley (SD) rats for 90 days. During the subchronic oral toxicity study, no mortality and toxicologically significant changes in clinical signs, food consumption, opthalmoscopic examination, hematology, clinical biochemistry, macroscopic findings, organ weights and histopathological examination were noted in animal administered diet containing bruchid-resistant mung bean. These results demonstrated that bruchid resistant mung bean is as safe as conventional mung bean.

Biochemical Basis for Bruchid Resistance in Cowpea, Chickpea and Soybean Genotypes

Biochemical Basis for Bruchid Resistance in Cowpea, Chickpea and Soybean Genotypes

Identification of quantitative trait loci for bruchid (Caryedon serratus Olivier) resistance components in cultivated groundnut (Arachis hypogaea L.)

Groundnut bruchid (Caryedon serratus Olivier) is a major storage insect pest that significantly lowers the quality and market acceptance of the produce. Screening for resistance against groundnut bruchid in field conditions is difficult due to the variation in environmental factors and possible occurrence of biotypes. Hence, identification of tightly linked markers or quantitative trait loci (QTLs) is needed for selection and pyramiding of resistance genes for durable resistance. A population of recombinant inbred lines derived from a cross between VG 9514 (resistant) and TAG 24 (susceptible) was screened for five component traits of bruchid resistance in 2 years. The same population was genotyped with 221 polymorphic marker loci. A genetic linkage map covering 1,796.7 cM map distance was constructed with 190 marker loci in cultivated groundnut. QTL analysis detected thirteen main QTLs for four components of bruchid resistance in nine linkage groups and 31 epistatic QTLs for total developmental period (TDP). Screening in 2 years for bruchid resistance identified two common main QTLs. The common QTL for TDP, qTDP-b08, explained 57–82 % of phenotypic variation, while the other common QTL for adult emergence, qAE2010/11-a02, explained 13–21 % of phenotypic variation. Additionally, three QTLs for TDP, adult emergence and number of holes and one QTL for pod weight loss were identified which explained 14–39 % of phenotypic variation. This is the first report on identification of multiple main and epistatic loci for bruchid resistance in groundnut.

Inheritance of bruchid resistance and morphological traits in greengram

Feeding assay of F2 and F3 seeds, derived from a cross between bruchid resistant wild greengram Sub2 and a bruchid susceptible high yielding cultivar B1 revealed that bruchid resistance in greengram is dominant and governed by a few major genes (probably two) with some modifiers. A single dominant gene is responsible for the production of purple coloration in the hypocotyl region at the seedling stage of greengram. Involvement of two or more genes along with the effects from environment was observed for the traits like leaf lobation, leaf vein colour, seed lusture and seed shape. No particular seed coat colour or phenotypic traits was found to be associated with the bruchid resistance. Significant and positive correlation was there between seed weight and bruchid susceptibility.

Evaluation of Screening Methods for Bruchid Beetle (Callosobruchus chinensis) resistance in Greengram (Vigna radiata) and Blackgram (Vigna mungo) genotypes and influence of seed physical characteristics on its infestation

Bruchid beetle, Callosobruchus spp. (Coleoptera: Bruchidae) cause substantial reduction in quantity and quality of legumes during storage in tropical and sub-tropical regions of the world. C. chinensis is the most important bruchid in Asia and causes considerable damage to Vigna seeds. Four hundred seventy five accessions of two Vigna species, [335 of Vigna radiata (greengram) and 140 of Vigna mungo (blackgram)] were initially evaluated for resistance to bruchid beetle through ‘free choice’ test. Eight greengram and nine blackgram resistant accessions were further evaluated under lab conditions using ‘no choice’ test. Four greengram accessions (LM 131, V 1123, LM 371 and STY 2633) were found moderately resistant with less percentage survival (38.9 to 51.6%) and prolonged developmental period (30.5 to 31.5 days) as compared to susceptible check (90.8% survival and 26.1 days of developmental period). Similarly in blackgram, three accessions (UH 82-5, IC 8219 and SPS 143) were moderately resistant with less percentage survival (33.7 to 42.0%) and prolonged developmental period (26.8 to 28.1 days) as compared to susceptible check (83.2% survival and developmental period of 24.2 days). Physical characteristics of the seeds were related with the ovipositional preference of the bruchid. In greengram, lesser number of eggs were recorded in small and shiny seeds as compared to large and dull seeds while in blackgram, small and black seeds recorded lower number of eggs as compared to large and green seeds. In this study, ‘no choice’ test seemed to be most reliable and potentially useful for screening of bruchid resistance. Since, no cultivated germplasm exhibited complete resistance, the moderately resistant genotypes identified in the present study hold promise in breeding programme of greengram and blackgram.

10.5937/ratpov51-5488 = Legume improvement program at AVRDC - The World Vegetable Center: Impact and future prospects

Legume breeding at AVRDC - The World Vegetable Center currently focuses on two crops: mungbean (Vigna radiata [L.] Wilzcek var. radiata) and vegetable soybean (Glycine max [L.] Merrill). High yielding, short duration mungbean varieties bred by AVRDC in conjunction with 29 national partners across Asia revolutionized the industry over the last two decades and increased global production by more than a third. New sources of resistance to mungbean yellow mosaic disease have been identified in related species such as black gram (Vigna mungo [L.] Hepper) and are being introgressed into elite mungbean lines. Improving protein quality by transferring high methionine and bruchid resistance traits from black gram is in progress. Selection of local land races and transfer of desirable traits from grain soybean are being used to develop vegetable soybean with higher pod yield, improved seed size and colour, higher sugar content, basmati flavour, less sensitive to photoperiod and temperature.

The major quantitative trait locus for mungbean yellow mosaic Indian virus resistance is tightly linked in repulsion phase to the major bruchid resistance locus in a cross between mungbean [Vigna radiata (L.) Wilczek] and its wild relative Vigna radiata ssp. sublobata

Mungbean yellow mosaic Indian virus (MYMIV) and bruchid infestation are severe production constraints of mungbean in South Asia, a major global mungbean production area. Marker-assisted selection for resistance against these disorders while maintaining or even improving agronomic traits is an important step toward breeding elite mungbean varieties. This study employed recombinant inbred lines (F12) derived from a cross between MYMIV-tolerant Vigna radiata NM92 and bruchid-resistant V. radiata ssp. sublobata TC1966 to identify chromosomal locations associated with disease and insect pest resistance and seed traits. A linkage map comprising 11 linkage groups was constructed with random amplified polymorphic DNA (RAPD), sequence characterized amplified regions (SCAR), cleaved amplified polymorphic DNA (CAP), amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Quantitative trait loci (QTLs) for MYMIV and bruchid resistance, 100 seed weight and seed germination rate were identified. Three major QTLs for MYMIV and one major bruchid resistance locus were mapped on LG 9. The resistance alleles were contributed by the MYMIV tolerant parent NM92 and the bruchid resistant parent TC1966 respectively. One of the MYMIV QTLs was tightly linked in repulsion phase to the bruchid resistance locus. In addition, three minor QTLs for MYMIV resistance were found, where the resistance alleles were contributed by TC1966. Lines combining MYMV resistance alleles from both parents have greater resistance to MYMIV than the tolerant parent. Two minor bruchid resistance QTLs were identified in TC1966. Furthermore, three QTLs each for 100 seed weight and germination rate were detected. The markers defining the QTLs identified in this study will be useful in marker-assisted breeding of improved mungbean varieties in the future.

QUES, a new Phaseolus vulgaris genotype resistant to common bean weevils, contains the Arcelin-8 allele coding for new lectin-related variants

In common bean (Phaseolus vulgaris L.), the most abundant seed proteins are the storage protein phaseolin and the family of closely related APA proteins (arcelin, phytohemagglutinin and α-amylase inhibitor). High variation in APA protein composition has been described and the presence of arcelin (Arc) has been associated with bean resistance against two bruchid beetles, the bean weevil (Acanthoscelides obtectus Say) and the Mexican bean weevil (Zabrotes subfasciatus Bohemian). So far, seven Arc variants have been identified, all in wild accessions, however, only those containing Arc-4 were reported to be resistant to both species. Although many efforts have been made, a successful breeding of this genetic trait into cultivated genotypes has not yet been achieved. Here, we describe a newly collected wild accession (named QUES) and demonstrate its resistance to both A. obtectus and Z. subfasciatus. Immunological and proteomic analyses of QUES seed protein composition indicated the presence of new Arc and arcelin-like (ARL) polypeptides of about 30 and 27kDa, respectively. Sequencing of cDNAs coding for QUES APA proteins confirmed that this accession contains new APA variants, here referred to as Arc-8 and ARL-8. Moreover, bioinformatic analysis showed the two proteins are closely related to APA components present in the G12949 wild bean accession, which contains the Arc-4 variant. The presence of these new APA components, combined with the observations that they are poorly digested and remain very abundant in A. obtectus feces, so-called frass, suggest that the QUES APA locus is involved in the bruchid resistance. Moreover, molecular analysis indicated a lower complexity of the locus compared to that of G12949, suggesting that QUES should be considered a valuable source of resistance for further breeding purposes.

Bioassay studies for bruchid (Callosobruchus chinensis) resistance in

The results of bioassay indicated that per cent adult emergence, mean time of adult emergence and per cent weight loss were most important parameters which helped in categorizing the genotypes into susceptible or resistant. Out of nine interspecific progenies, one of progeny UPAS120 × scarabaeiodes was found least susceptible for Callosobruchus chinensis, while other progenies in the descending order for resistance to bruchid were UPAS120 × cajanifolius, PA134 × C. scarabaeiodes, PA134 × C. acutifolius, ICPL84023 × C. cajanifolius and ICPL84023 × scarabaeiodes. Since genetic resistance is the cheapest source of resistance in managing the biotic stress, the resistant material found in this study will definitely useful in the pigeonpea improvement programme especially for bruchid resistance.

Molecular markers linked with bruchid resistance in Vigna radiata var. Sublobata and their validation

Bruchid, Callosobruchus chinensis (L.) is an important pest of Vigna radiata during storage. RFLP and PCR based markers identified, linked with bruchid resistance gene in wild accession of greengram (V. radiata var. Sublobata) either collected from Madagaskar or Australia. Whether these markers will be useful for marker assisted introgression of bruchid resistance gene from the Indian accession into the existing cultivars are not known. Here, we employed two STS based markers which were found earlier, to be linked with bruchid resistance gene in Australian accession ACC41. Only one primer pair, STSbr1 showed polymorphism among Indian Sublobata accession (Sub2) and other twelve green gram cultivars. Analysis of 113 segregating lines (F6) of a cross between a popular cultivar of West Bengal, B1 and Sub2 showed a cent percent co-segregation of resistant locus with the polymorphic fragment. STSbr1 behave as a dominant marker among Indian genotypes although it has been shown earlier a co-dominant banding pattern between ACC41 and other Australian Susceptible cultivars. Other STS marker, STSbr2, does not produce any polymorphic fragment among Sub2 and 18 greengram genotypes. STSbr1 employed in screening of 50 green gram accessions and found high efficiency in screening of bruchid resistant genotypes also. So STSbr1 will be useful for marker assisted selection and germplasm screening for development of bruchid resistant greengram.

Identification of quantitative trait loci for bruchid (Callosobruchus maculatus) resistance in black gram [Vigna mungo (L.) Hepper

An inter-subspecific mapping population was generated by crossing V. mungo var. mungo (cv. TU 94-2, bruchid susceptible) and V. mungo var. silvestris (bruchid resistant). About 37.8% of the bruchid completed their lifecycle on seeds of V. mungo var. silvestris compared with 100% on the susceptible variety TU 94-2. The total developmental period of C. maculatus on Vigna mungo var. silvestris was considerably extended (88 days as compared with 34 days on TU 94-2). A genetic linkage map constructed using recombinant inbred lines (RILs) in F9 generation with 428 markers [86 random amplified polymorphic DNA (RAPD), 47 simple sequence repeat (SSR), 41 inter-SSR (ISSR), 254 amplified fragment length polymorphism (AFLP)] was used for QTL detection. One hundred four individuals were used for detection of QTLs associated with bruchid resistance. The RILs exhibited a high level of variation in percentage adult emergence (0–100%) and developmental period (0–105 days). Two QTLs, Cmrae1.1 and Cmrae1.2, were identified for percentage adult emergence, on linkage group (LG) 3 and 4, respectively. For developmental period, six QTLs were identified, with two QTLs (Cmrdp1.1 and Cmrdp1.2) on LG 1, three QTLs (Cmrdp1.3, Cmrdp1.4, and Cmrdp1.5) on LG 2, and one QTL (Cmrdp1.6) on LG 10.

Genetic mapping of microsatellite markers around the arcelin bruchid resistance locus in common bean

The deployment in common beans (Phaseolus vulgaris L.) of arcelin-based bruchid resistance could help reduce post-harvest storage losses to the Mexican bean weevil [(Zabrotes subfasciatus (Boheman)]. Arcelin is a member of the arcelin-phytohemagglutinin-α-amylase inhibitor (APA) family of seed proteins, which has been extensively studied but not widely used in bean breeding programs. The purpose of this study was to evaluate microsatellite markers for genetic analysis of arcelin-based bruchid resistance and to determine the orientation of markers and the rate of recombination around the APA locus. A total of 10 previously developed microsatellites and 22 newly developed markers based on a sequenced BAC from the APA locus were screened for polymorphism and of these 15 were mapped with an F2 population of 157 individuals resulting from a susceptible × resistant cross of SEQ1006 × RAZ106 that segregated for both the arcelin 1 allele and resistance to the bruchid, Z. subfasciatus. Microsatellites derived from APA gene sequences were linked within 0.8 cM of each other and were placed relative to the rest of the b04 linkage group. In a comparison of genetic to physical distance on the BAC sequence, recombination was found to be moderate with a ratio of 125 kb/cM, but repressed within the APA locus itself. Several markers were predicted to be very effective for genetic studies or marker-assisted selection, based on their significant associations with bruchid resistance and on low adult insect emergence and positions flanking the arcelin and phytohemagglutinin genes.

Linkage disequilibrium at the APA insecticidal seed protein locus of common bean (Phaseolus vulgaris L.)

BackgroundAn interesting seed protein family with a role in preventing insect herbivory is the multi-gene, APA family encoding the α-amylase inhibitor, phytohemagglutinin and arcelin proteins of common bean (Phaseolus vulgaris). Variability for this gene family exists and has been exploited to breed for insect resistance. For example, the arcelin locus has been successfully transferred from wild to cultivated common bean genotypes to provide resistance against the bruchid species Zabrotes subfasciatus although the process has been hampered by a lack of genetic tools for and understanding about the locus. In this study, we analyzed linkage disequilibrium (LD) between microsatellite markers at the APA locus and bruchid resistance in a germplasm survey of 105 resistant and susceptible genotypes and compared this with LD in other parts of the genome.ResultsMicrosatellite allele diversity was found to vary with each of the eight APA-linked markers analyzed, and two markers within the APA locus were found to be diagnostic for bruchid resistance or susceptibility and for the different arcelin alleles inherited from the wild accessions. Arc1 was found to provide higher levels of resistance than Arc5 and the markers in the APA locus were highly associated with resistance showing that introgression of this gene-family from wild beans provides resistance in cultivated beans. LD around the APA locus was found to be intermediate compared to other regions of the genome and the highest LD was found within the APA locus itself for example between the markers PV-atct001 and PV-ag004.ConclusionsWe found the APA locus to be an important genetic determinant of bruchid resistance and also found that LD existed mostly within the APA locus but not beyond it. Moderate LD was also found for some other regions of the genome perhaps related to domestication genes. The LD pattern may reflect the introgression of arcelin from the wild into the cultivated background through breeding. LD and association studies for the arcelin gene, linked genes and other members of the APA family are essential for breaking linkage drag while maintaining high levels of bruchid resistance in common bean.

Relationship between bruchid resistance and seed mass in mungbean based on QTL analysis

Bruchids (Coleoptera: Bruchidae) can cause serious damage to mungbean and several other leguminous crops and there is a strong association between small seed size and bruchid resistance. In investigating the feasibility of breeding large-seeded cultivars with high levels of bruchid resistance, we studied the relationship between these two traits by QTL analysis. A major locus conferring resistance to Callosobruchus chinensis was identified from a wild mungbean genotype, 'ACC41' (belonging to Vigna radiata var. sublobata), collected in Australia. The proportion of the C. chinensis resistance response that could be attributed to this single QTL varied among four different resistance assays. The highest value reached was 98.5%, suggesting that bruchid resistance in this genotype is likely conditioned by this single locus. The QTL was robust and its detection was not affected by the use of different sources of the insect, different lengths and conditions of seed storage, or different bruchid resistance assay methods. This bruchid resistance QTL was coincident with one of the loci conferring seed mass detected from the three seed sources produced in Australia. However, such a co-location was not detected for the seed source produced in China. Covariance analysis revealed a complex relationship between seed mass and bruchid resistance. Nevertheless, the effect of the bruchid resistance QTL remained highly significant for all four assays after the effect of seed mass was accounted for. These results, together with the relationship between the bruchid resistance QTL identified in this study and a second one detected previously in a wild mungbean genotype from Madagascar, are discussed.

Mapping of quantitative trait loci for a new source of resistance to bruchids in the wild species Vigna nepalensis Tateishi & Maxted (Vigna subgenus Ceratotropis)

Azuki bean breeders have long been interested in producing azuki bean [Vigna angularis (Willd.) Ohwi & Ohashi] varieties with bruchid resistance. A new bruchid (Callosobruchus spp.) resistance source was found in V. nepalensis Tateishi & Maxted, a species that is cross compatible with azuki bean. Quantitative trait loci (QTLs) analysis for resistance to C. chinensis (L.) and C. maculatus (F.) was conducted using F2 (V. nepalensisxV. angularis) and BC1F1 [(V. nepalensisxV. angularis)xV. angularis] populations derived from crosses between the bruchid resistant species V. nepalensis and bruchid susceptible species V. angularis. Resistance was measured using two traits, percentage of seeds damaged by bruchids and the time taken for adult bruchids to emerge from seeds. Based on the results from both populations seven QTLs were detected for bruchid resistance; five QTLs for resistance to C. chinensis and two QTLs for resistance to C. maculatus. The different locations found for some resistance QTL to the two bruchid species suggests different resistance mechanisms. QTLs on linkage group (LG) 1 and LG2 for bruchid resistance to C. chinensis co-localized with seed size QTLs suggesting that incremental increase in seed size accompanied susceptibility to C. chinensis. Based on linked markers the QTL on these two linkage groups appear to be the same as previously reported in other Asian Vigna. However, several other QTLs were newly detected including one on LG4 that appears unrelated to seed size. Transfer of these new sources of bruchid resistance from V. nepalensis to azuki bean will be aided by the progress being made in azuki genome mapping.

Heredity Analysis and Gene Mapping of Bruchid Resistance of a Mungbean Cultivar V2709

Bruchid is a serious insect pest of mungbean [ Vigna radiata (L.) Wilczek] and can inflict serious loss. A resistant variety from India, V2709, was crossed with a susceptible variety, Zhonglü 1, from the World Vegetable Center, Asian Vegetable Research and Development Center (AVRDC). Segregation of the F 2, BC 1F 1, and F 3 populations showed that bruchid resistance of V2709 is controlled by a single dominant locus. To find molecular marker linked with the resistant locus, 63 randomly amplified polymorphic DNA markers and 113 sets of SSR/STS primers were used in a bulked segregant analysis. Two of the markers, OPC-06 and STSbr2, were found to be linked with the locus (named as Br2). Further analysis suggested that the genetic distances between these two markers and Br2 were 11.0 and 5.8 cM, respectively.

Development of a molecular marker for a bruchid (Callosobruchus chinensis L.) resistance gene in mungbean

Bruchid, Callosobruchus spp. (Coleoptera: Bruchidae), is a serious pest during storage of seeds of mungbean (Vigna radiata (L.) Wilczek) and other Vigna species. A source of resistance to this pest has been identified in Vigna sublobata (Roxb.) Bairig. accession TC1966. Two hundred recombinant inbred lines at the F12 generation have been developed for molecular mapping of bruchid resistance (Br) gene in TC1966. Through bulked segregant analysis (BSA), ten randomly amplified polymorphic DNA (RAPD) markers associated with the bruchid resistance gene were successfully identified. A total of four closely linked RAPDs were cloned and transformed into sequence characterized amplified region (SCAR) and cleaved amplified polymorphism (CAP) markers. Seven CAPs developed from the identified RAPD markers showed tighter linkage with the Br gene than the original RAPD. Through transformation of RAPDs into CAPs, codominant markers for bruchid resistance were successfully obtained. Homozygous genotypes of these PCR-based markers were estimated to contribute 85% of the variance for seed damage when the insect assay was performed under favorable growth conditions for bruchid.

Pyramiding of insecticidal compounds for control of the cowpea bruchid (Callosobruchus maculatus F.)

The cowpea bruchid (Callosobruchus maculatus F.) (Chrysomelidae: Bruchini) is a major pest of stored cowpea grain. With limited available technologies for controlling the bruchid, transgenic cowpeas with bruchid resistance genes engineered into them could become the next management tools. An investigation was made of two different sets of potential transgenic insecticidal compounds using an artificial seed system: (i) CIP-PH-BT-J and recombinant egg white avidin, and (ii) avidin and wheat alpha-amylase inhibitor. CIP-PH-BT-J (0.1%; 1000 mg kg(-1)) and recombinant egg white avidin (0.006%; 60 mg kg(-1)) incorporated separately into artificial seeds caused 98.2 and 99% larval mortality rates respectively. Combining CIP-PH-BT-J and avidin in the same artificial seed provided additional mortality compared with each factor incorporated singly; no insects survived in seeds with the combined toxins. Similarly, when avidin and wheat alpha-amylase inhibitor (alphaAI) (1%; 10 g kg(-1)) were incorporated separately into artificial seeds, this caused 99.8 and 98% mortality respectively. However, in combination, avidin and alphaAI did not increase mortality, but they did cause a significant increase in developmental time of the cowpea bruchids. These results emphasize that the joint action of potential insecticidal compounds cannot be predicted from results obtained separately for each compound, and they suggest potential transgenes for further consideration.

Assessment of the importance of α-amylase inhibitor-2 in bruchid resistance of wild common bean

Both alpha-amylase inhibitor-2 (alphaAI-2) and arcelin have been implicated in resistance of wild common bean (Phaseolus vulgaris L.) to the Mexican bean weevil (Zabrotes subfasciatus Boheman). Near isogenic lines (NILs) for arcelin 1-5 were generated by backcrossing wild common bean accessions with a cultivated variety. Whereas seeds of a wild accession (G12953) containing both alphaAI-2 and arcelin 4 were completely resistant to Z. subfasciatus, those of the corresponding NIL were susceptible to infestation, suggesting that the principal determinant of resistance was lost during backcrossing. Three independent lines of transgenic azuki bean [Vigna angularis (Willd.) Ohwi and Ohashi] expressing alphaAI-2 accumulated high levels of this protein in seeds. The expression of alphaAI-2 in these lines conferred protection against the azuki bean weevil (Callosobruchus chinensis L.), likely through inhibition of larval digestive alpha-amylase. However, although the seed content of alphaAI-2 in these transgenic lines was similar to that in a wild accession of common bean (G12953), it did not confer a level of resistance to Z. subfasciatus similar to that of the wild accession. These results suggest that alphaAI-2 alone does not provide a high level of resistance to Z. subfasciatus. However, alphaAI-2 is an effective insecticidal protein with a spectrum of activity distinct from that of alphaAI-1, and it may prove beneficial in genetic engineering of insect resistance in legumes.

Inheritance of seed resistance to bruchids in cultivated mungbean (Vigna radiata, L. Wilczek)

Bruchid beetles or seed weevils are the most devastating stored pests of grain legumes causing considerable loss to mungbean (Vigna radiata (L.) Wilczek). Breeding for bruchid resistance is a major goal in mungbean improvement. Few sources of resistance in cultivated genepool were identified and characterized, however, there has been no study on the genetic control of the resistance. In this study, we investigated the inheritance of seed resistance to Callosobruchus chinensis (L.) and C. maculatus (F.) in two landrace mungbean accessions, V2709BG and V2802BG. The F1, F2 and BC generations were developed from crosses between the resistant and susceptible accessions and evaluated for resistance to the insects. It was found that resistance to bruchids in seeds is controlled by maternal plant genotype. All F1 plants derived from both direct and reciprocal crosses exhibited resistance to the bruchids. Segregation pattern of reaction to the beetles in the F2 and backcross populations showed that the resistance is controlled by a major gene, with resistance is dominant at varying degrees of expressivity. Although the presence of modifiers was also observed. The gene is likely the same locus in both V2709BG and V2802BG. The resistant gene is considered very useful in breeding for seed resistance to bruchids in mungbean.