Pigeonpea Plants Research Articles

Water‒soil-air‒plant mutual feedback mechanism under the application of red bed composite polymers.

Red bed composite polymers composed of weathered red bed soil, adhesive materials, and water-retaining materials have been applied as a new type of material for environmental restoration. However, the promotion and application of this material has been limited by a lack of understanding of its action mechanism in environmental restoration. The objective of this study is to innovatively propose a water‒soil-air‒plant mutual feedback mechanism based on this material. Therefore, water‒soil-air‒plant mutual feedback tests were conducted in this study under 3 initial water contents and 10 red bed composite polymers ratios. Key parameters, namely, water content, soil conductivity, pH, temperature, O2 and CO2 contents, pigeon pea (Cajanus cajan) germination number and plant height were monitored and analyzed. As the results, a mutual feedback mechanism driving water retention, soil consolidation, air retention, and plant rooting was revealed under the application of red bed composite polymers. And, suitable environments and optimal compositions for this material are proposed. The study results provide a theoretical basis for the large-scale application of red bed composite polymers.

Mitigation of heavy metal toxicity in pigeon pea by plant growth promoting Pseudomonas alcaliphila strain PAS1 isolated from contaminated environment.

The risk of arsenic contamination is rising globally, and it has negative impacts on the physiological processes and growth of plants. Metal removal from contaminated soils can be accomplished affordably and effectively with plant growth promoting rhizobacteria (PGPR)-based microbial management. From this angle, this research evaluated the mitigation of arsenic toxicity using the bacteria isolated from contaminated site, Mettur, Salem district, South India. The newly isolated bacterial strain was screened for plant growth promotion potential and arsenic tolerance such as (100ppm, 250ppm, 500ppm, 800ppm and 1200ppm). The metal tolerant rhizobacteria was identified using 16S rRNA gene sequence analysis as Pseudomonas alcaliphila strain PAS1 (GenBank accession number: OQ804624). Pigeon pea (Cajanus cajan) plants were used in pot culture experiments with varying concentrations of arsenic, (5ppm, 10ppm and 25ppm) both with and without bacterial culture, for a period of 45days. At the concentration of 25ppm after the application of PAS1 enhanced the plant growth, protein and carbohydrate by 35.69%, 18.31% respectively. Interestingly, P. alcaliphila strain PAS1 significantly reduced the stress-induced elevated levels of proline, flavonoid, phenol and antioxidant enzyme in pigeon pea plants was 40%, 31.11%, 27.80% and 20.12%, respectively. Consequently, PAS1 may significantly reduce the adverse effects that arsenic causes to plant development in acidic soils, improve plant uptake of nutrients, and increase plant production. The findings of this study reveal that P. alcaliphila PAS1 is intrinsic for phytoremediation by reducing arsenic accumulation in the root and shoot.

Harnessing Plant Growth–Promoting and Wilt‐Controlling Biopotential of a Consortium of Actinomycetes and Mycorrhizae in Pigeon Pea

ABSTRACTFusarium‐induced wilt significantly affects the cultivation and yield of pigeon peas. This warrants sustainable disease management while promoting plant growth. The present study investigated the biopotential of coinoculation of Streptomyces pseudogriseolus S‐9 and Rhizophagus irregularis for plant growth promotion and mitigation of the impact of Fusarium wilt on pigeon pea over three seasons at pot and field levels. Pigeon pea plants were subjected to Fusarium wilt stress and treated with different inoculation strategies, including single and combined applications of S. pseudogriseolus S‐9 and R. irregularis. Plant growth parameters and yields were assessed to evaluate the efficacy of the coinoculation. In the pot experiment, T‐6 treatment resulted in the longest root (62.56 ± 0.01 cm) and shoot (70.24 ± 0.01 cm) lengths compared to the application of commercial biofungicide T‐8 (Trichoderma). This treatment also significantly influenced the yield of potted plants. It resulted in the highest fresh root weight (62.27 ± 0.01 g), fresh shoot weight (70.24 ± 0.02 g), maximum root (55.25 ± 0.01 g) and shoot dry weights (52.25 ± 0.01 g). In the field experiment, pigeon pea plants treated with the bioinoculant also demonstrated a substantial increase (р ≤ 0.05) in total grain yield, the weight of 100 grains, and the number of filled grains compared to the control group in all experimental seasons. In vitro, antagonism assay of compatibility of mycorrhizae and bacteria showed good activity using powder formulation. Thus, the consortium application inspired the broad application of Streptomyces and Trichoderma as effective bioinoculants for wilt management and yield improvement in pigeon peas.

Bio Inspired CdO Nanoparticles: A Robust and Recyclable Catalyst Towards the Synthesis of Dihydropyrimidone Derivatives via One Pot Three‐Component Coupling Reaction

AbstractAn innovative and environmentally sustainable approach is presented for the synthesis of cadmium oxide nanoparticles (CdONPs), leveraging the leaf extract of the pigeon pea plant (Cajanus cajan) as both reductive and capping agents. This environmentally friendly heterogeneous CdONPs was meticulously characterized through FT‐IR, PXRD, HR‐TEM, SEM‐EDAX, XPS and UV‐Vis spectroscopic analyses. These NPs were subsequently applied to facilitate the three‐component Biginelli reaction using ethyl acetoacetate, urea, and substituted benzaldehydes for producing dihydropyrimidone derivatives in good to excellent yield. The methodology was tested for different aldehydes containing electron‐withdrawing and electron‐donating groups. The catalyst demonstrated consistent performance over approximately five cycles, exhibiting negligible loss in yield and catalytic potential. The proposed mechanistic pathway of the reaction was elucidated through intermediate mass analysis and further validated by Density Functional Theory (DFT) calculations and catalytic surface adsorption studies.

BamFx Induced Resistance by Seed Priming Method against Fusarium sp. in Cajanus cajan (L.) Mill sp.

Background: Pigeon pea [Cajanus cajan (L.) Mill sp.] enriches the soil through symbiotic nitrogen fixation. The pigeon pea plants are susceptible to a number of pathogenic fungi including Aspergillus sp. and Fusarium sp. Bam-FX® is a micromineral formulation that directly affects the physiological mechanisms and innate immune system of plants to help them overcome both abiotic and biotic stresses without the need for any form of genetic modification. Methods: In this study, we have tested different dilutions to soak the pigeon pea seeds. On 21th day, optimum germination (94%) was found in seeds treated with BamFX (1:1000) compared to 75% germination in untreated seeds. Result: The fungi were isolated from the soil and identified using 18s rRNA gene sequencing. The seedlings in BamFx treated groups were found resistant to pathogenic fungi, whereas, more than 97% in the untreated groups were found infected or diseased. The increased germination efficiency and resistance to fungal infections in BamFx treated seedlings proved a priming effect due to BamFx in pigeon pea seeds.

Unveiling the potential of Trichoderma harzianum against Heterodera cajani in pigeon pea: impact on cysts, egg and juveniles abundance

BackgroundPigeon pea is affected by the cyst nematode Heterodera cajani limiting the production. H. cajani can be managed by biological agents such as Trichoderma harzianum. Thus, the determination of this experiment was to estimate native strains of T. harzianum isolated from pigeon pea fields in India on population of cyst, eggs and juveniles of H. cajani. Pots experiment was conducted at the playhouse of Sam Higginbottom University of Science and Technology, Prayagraj (UP), India, during the year of 2018–2020. Earthen pots were filled with sterilized soil @ 10 kg/pot for each replicate of the treatments. Ten days before sowing of the pigeon pea seed, about 5000 spores of T. harzianum were amended in to the soil for proper colonization. Fifteen days after seed germination, 200 cysts/pot were inoculated near the root zone of pigeon pea plant. The pots were irrigated when required. Observations were recorded of cyst population, eggs and second juveniles of H. cajani/500gm of pigeon pea rhizospheric soil at 90 days after sowing.ResultsAmong all the isolates of T. harzianum, the treatment (T 7) reduced of cyst population (12), eggs population (234) and juveniles’ population (153) as compared with all other treatments including control at 90 days after sowing of pigeon pea seeds in the year 2018–2019. Similarly, in 2019–2020 reduction in cyst population (11), eggs population (189) and juveniles population (160) was observed at 90 days after sowing in Trichoderma isolates (T 7) as compared to control.ConclusionsThe findings of this study are very relevant since seven isolates of native T. harzianum were promising to suppress the number of cysts in 79.31 and 83.07%, eggs in 22.00 and 38.83% and juveniles’ population in 17.74 and 20.39% of the nematode H. cajani, besides promoting the pigeon pea plant growth.

Comparative Analysis of Mechanical and Thermal Properties of Lime Concrete Blocks Made with Pigeon Pea and Carrot Grass Plants as Partial Replacement of Fine Aggregates

Comparative Analysis of Mechanical and Thermal Properties of Lime Concrete Blocks Made with Pigeon Pea and Carrot Grass Plants as Partial Replacement of Fine Aggregates

Nitric oxide and AMF-mediated regulation of soil enzymes activities, cysteine-H2S system and thiol metabolites in mitigating chromium (Cr (VI)) toxicity in pigeonpea genotypes.

Cr (VI) hampers plant growth and yield by reducing essential nutrient uptake as it competes for phosphate and sulfate transporters. Nitric oxide (NO) and mycorrhization play important roles in mitigating Cr (VI) toxicity. Present study aimed to compare the potential of AMF (Arbuscular mycorrhizal fungi)-Rhizoglomus intraradices and NO (0.25mM) in alleviating Cr (VI) stress (0, 10 and 20mg/kg) in two differentially tolerant pigeonpea genotypes (Pusa 2001 and AL 201). Cr (VI) toxicity reduced growth, mycorrhizal colonization, nutrient uptake, and overall productivity by inducing reactive oxygen species (ROS) generation, with AL 201 more sensitive than Pusa 2001. NO and AM enhanced activities of soil enzymes, thereby increasing nutrients availability as well as their uptake, with AM more effective than NO. Both amendments reduced oxidative stress and restricted Cr (VI) uptake by increasing the activities of antioxidant and S- assimilatory enzymes, with Pusa 2001 more responsive than AL 201. NO was relatively more efficient in regulating cysteine-H2S system by increasing the activities of biosynthetic enzymes (ATP-sulfurylase (ATPS), O-acetylserine thiol lyase (OASTL), D-cysteine desulfhydrase (DCD) and L-cysteine desulfhydrase (LCD), while AM significantly increased glutathione reductase (GR), γ-glutamylcysteine synthetase (γ-ECS) enzymes activities and resultant glutathione (GSH), phytochelatins (PCs), and non-protein thiols (NP-SH) synthesis. Moreover, co-application of NO and AM proved to be highly beneficial in negating the toxic effects of Cr (VI) due to functional complementarity between them. Study suggested the combined use of NO and AM as a useful strategy in re-establishing pigeonpea plants growing in Cr (VI)-stressed environments.

Identification, characterization, and comprehensive expression profiling of floral master regulators in pigeon pea (Cajanus cajan [L.] Millspaugh).

Pigeon pea is an important protein-rich pulse crop. Identification of flowering master regulators in pigeon pea is highly imperative as indeterminacy and late flowering are impediments towards yield improvement. A genome-wide analysis was performed to explore flowering orthologous groups in pigeon pea. Among the 412 floral orthologs identified in pigeon pea, 148 genes belong to the meristem identity, photoperiod-responsive, and circadian clock-associated ortholog groups. Our comparative genomics study revealed purifying selection pressures (ka/ks) on floral orthologs, and duplication patterns and evolution through synteny with other model species. Phylogenetic analysis of floral genes substantiated a connection between pigeon pea plant architecture and flowering time as all the PEBP domain-containing genes belong to meristem identity floral networks of pigeon pea. Expression profiling of eleven major orthologs in contrasting determinate and indeterminate genotypes indicated that these orthologs might be involved in flowering regulation. Expression of floral inducer, FT, and floral repressor, TFL1, was non-comparable in indeterminate genotypes across all the developmental stages of pigeon pea. However, dynamic FT/TFL1 expression ratio detected in all tissues of both the genotypes suggested their role in floral transition. One TFL1 ortholog having high sequence conserveness across pigeon pea genotypes showed differential expression indicating genotype-dependent regulation of this ortholog. Presence of conserved 6mA-methylation patterns in light-responsive elements and in other cis-regulatory elements of FT and TFL1 across different plant genotypes indicated possible involvement of epigenetic regulation in flowering.

Biocontrol efficacy and induced defense mechanisms of indigenous Trichoderma strains against Fusarium wilt [F. udum (Butler)] in pigeonpea

This study aimed to identify efficient Trichoderma isolate(s) for the management of Fusarium wilt in pigeonpea. In vitro and in vivo (greenhouse) experiments were conducted to evaluate 17 Trichoderma isolate(s) for their anti-pathogenic activity, induction of plant biochemical functions, disease suppression, and plant growth traits comparing with standard Trichoderma strains. Among the indigenous isolates, IIPRTh-31 (T. asperellum) and IIPRTh-33 (T. afroharzianum) had a higher mycelia growth inhibition in vitro [membrane assay (>74%), binary assay (>65%)]. Seed treatment with IIPRTh-31 and IIPRTh-33 isolates led to an increase in peroxidase (173–244%), polyphenol oxidase (48–80%), phenylalanine ammonia–lyase (147–178%) activities in pigeonpea plants over control and reduced disease incidence by 78–85%. Hence, IIPRTh-31, and IIPRTh-33 strains demonstrate excellent bio-control of Fusarium wilt in pigeonpea via induction of defense-related enzymes. These isolates have been registered (Registration No. NAIMCC-R-5, NAIMCC-R-6) and used for talc-based bio-formulations for field application.

RESPONSE OF HELICOVERPA ARMIGERA TO VARIOUS VOLATILES IN HOST PLANTS

Adult H. armigera were tested using a four-choice olfactometer to see how they orientated in response to volatiles from marigold, tomato, chickpea, and pigeonpea plants. Both female and male H. armigera moths were found to be most attracted to the volatiles of marigold plants, with a 35.01 percent attraction to uncut twigs and a 42.32 percent attraction to cut twigs, respectively. The volatile compounds from tomato plants elicited the second highest reaction. Volatiles from the host plant were identified using GC-MS testing. Eleven volatile compounds were isolated from marigolds, ten from tomatoes, seventeen from pigeonpeas, and ten from chickpeas.

Biochemical Alterations in Different Pigeon Pea Genotypes due to Sterility Mosaic Disease

Background: The sterility mosaic disease in pigeon pea caused by pigeon pea sterility mosaic virus is a serious threat to pigeon pea cultivation in India. A little information is available on the biochemical changes in pigeon pea plant against the SMD disease. Hence present study was taken to know the biochemical alterations in different pigeon pea genotypes due to sterility mosaic disease. Methods: Studies were conducted on the composition of the chlorophyll pigment, total soluble protein (%), total sugars, phenol, tannins, peroxidase and phenol peroxidase in six different genotypes. Result: The results of the study showed that there was a reduction in chlorophyll pigment composition, total soluble protein (%) and total sugars in all infected genotypes, but the reduction in resistant genotypes was less compared to other genotypes. In resistant genotypes, the amounts of phenols, tannins, peroxidase and phenol peroxidase were increased, where as in susceptible genotypes, they were roughly equal to the amounts in uninoculated genotypes. The increase in phenols, tannins, peroxidase and phenol peroxidase in resistant genotypes can be correlated with disease resistance.

Rhizobium Inoculation Improved the Rhizosphere P Dynamics and P Uptake Capacity of Pigeon Pea Plants Grown in Strongly Weathered Soil Only under P Fertilized Conditions

The improvement of phosphorus (P) use efficiency (PUE) is a critical problem in crop production because of phosphorus’ scarcity. Especially in strongly weathered soil with a high P fixation capacity, a low PUE generally limits plant growth. Here, in a 70-day pigeon pea cultivation pot experiment using Ultisols, we evaluated the effects of Rhizobium inoculation (−I/+I) on the plant growth, rhizosphere, bulk soil P dynamics, and plant root P acquisition characteristics, with or without P fertilization (0P: no P application; 50SSP:50 kg P ha−1 with single superphosphate). The combination of Rhizobium inoculation with P fertilization (50SSP + I) increased the plant growth, P uptake, and organic acid content per pot by 63%, 41%, and 130%, respectively, but not without P fertilization (0P + I). The labile and moderately labile inorganic P (NaHCO3-Pi and NaOH-Pi) contents were higher (55% and 44%, respectively) in the rhizosphere soil than those in the bulk soil in the 50SSP + I treatment, indicating the efficient solubilization of the applied P under the 50SSP + I treatment. The fertilized PUE was higher in the 50SSP + I treatment (26%) than that in the 50SSP−I treatment (15%). Thus, these results suggest that Rhizobium inoculation with 50SSP should stimulate plant root P acquisition characteristics, leading to the solubilization of applied P in the rhizosphere and efficient plant P uptake. In conclusion, the 50SSP + I treatment effectively improved the PUE of pigeon peas in strongly weathered soil.

Produtividade e extração de nutrientes pelo capim paiaguás submetido a doses de nitrogênio em cultivo solteiro e consorciado com feijão guandu

ABSTRACT The objective of this work was to evaluate the productivity and extraction of macronutrients by Urochloa brizantha cv. BRS Paiaguás (Syn. Brachiaria brizantha cv. BRS Paiaguás) single and intercropped with pigeon pea (Cajanus cajan cv. BRS Mandarim), subjected to four doses of nitrogen applied in topdressing (0, 80, 160 and 240 kg ha-1). The experiment was carried out in São Luís de Montes Belos, GO, in soil classified as dystrophic red latosol, under Cerrado conditions. Plant height and dry mass of pigeon pea, plant height, number of tillers, dry mass, and macronutrient extraction by Paiaguás palisadegrass were evaluated. Higher mass production was observed in the pasture intercropped with the legume, requiring a lower amount of N. Based on the results exposed, the cultivation of Paiaguás palisadegrass reaches higher productivity when intercropped with a legume such as pigeon pea, in addition to providing greater efficiency in the use of nutrients such as N, P and K. Nitrogen fertilization has a negative influence on the production of dry mass and height of pigeon pea plants.

Effect of Different Inoculum Level of Meloidogyne incognita on Chlorophyll Content of Pigeon Pea, Cajanus cajan (L.)

A pot culture experiment was conducted during Kharif season in the year 2021- 2022 at Green polyhouse, Department of Nematology, College of Agriculture, Odisha University of Agriculture and Technology, Bhubaneswar, Odisha in order to study effect of different inoculum level of M. incognita on chlorophyll content of pigeon pea. The experiment was laid out in Completely randomized design (CRD) with 5 treatments i.e T1 (500 J2/plant), T2(1000J2 / Plant), T3(1500J2/plant), T4(2000J2/plant), T5(Control)and 4 varieties were UPAS-120(R), IPA-15-1 (MR), IPA 14-7(S), CO-6(HS). To find out the effect of increase in inoculum level of nematode on chlorophyll content of pigeon pea leaves showed that highest reduction in chlorophyll in treatment T4 then T3, T2 and then T1 over control T5. The results have demonstrated that nematode infestation leads to highest decreased by 41.75% total chlorophyll content (a+b) in UPAS -120(R)) in the leaves and highest decrease found in case of high inoculum level inoculation of nematodes in the pigeon pea plant.

Unraveling the mechanism of sulfur nutrition in pigeonpea inoculated with sulfur-oxidizing bacteria.

An investigation was carried out to understand the mechanism(s) involved in the uptake of sulfur (S) as sulfate in pigeonpea following single inoculation of two sulfur-oxidizing bacteria (SOB), Stenotrophomonas maltophilia and Stenotrophomonas pavanii in the treatments amended with either elemental sulfur (S0) or sulfate (S6). Colonization potential and biofilm formation were analyzed through confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM). Furthermore, the effect of seed inoculation on root architecture, expression of genes involved in sulfur oxidation (sox) in bacterial inoculants, and genes involved in sulfate transport in pigeonpea (PpSULTR) were analyzed to correlate with the higher uptake of S in roots and shoots of pigeonpea. Both the SOB exhibited a good colonization potential and biofilm formation on the roots of pigeonpea. Among the 11 sox genes targeted in rhizosphere of pigeonpea, expression was achieved for seven genes, which showed 2-fold increase in treatments inoculated with S. maltophilia and amended with either S6 or S0. The inoculation of S. maltophilia and amendment of S0 led to increased expression of PpSULTR genes by several folds in roots. The inoculation of SOB had a significant influence on non-enzymatic (osmolytes like proline) and enzymatic (PAL, peroxidase, superoxide dismutase, and catalase) levels. The results revealed a significant increase in sulfur uptake in roots and shoots in treatment inoculated with S. maltophilia and amended with S6. The investigation showed that the SOB-mediated over-expression of PpSULTR genes in roots of pigeonpea and sox genes in the rhizosphere were acting synergistically in facilitating higher uptake and translocation of S in roots and shoots of pigeonpea plants.

Nutraceutical Enrichment of Animal Feed by Filamentous Fungi Fermentation

There is an urgent need for improvements in animal production, particularly for ruminants, such that more sustainable and efficient processes are developed for obtaining more nutritious and efficient feeds. Filamentous fungi can add value to residual plant biomass, and may also have the potential to produce metabolites and enrich plant biomasses used in animal nutrition, converting them into nutraceutical sources. Thus, in this work, filamentous fungal fermentation of ruminant feed biomasses commonly used in Brazil was performed, and the enrichment for bioactive metabolites was tested. For this, Fistulina hepatica, Ganoderma lucidum, Pleurotus pulmonarius, Panus lecomtei, and Aspergillus terreus were grown for 28 days on different substrates: starchy grains- (sorghum, oat, and corn), fibrous substrates (coast-cross, rice husk, and moringa plant) and protein-rich substrates (cottonseed cake and pigeon pea plant). Fermented substrates were evaluated for laccase activity, crude protein, β-glucan, and lovastatin content. The highest growth rate was observed for G. lucidum in oat substrate (OT-01) (0.708 ± 0.035 cm/day) and F. hepatica in oat + coast-cross + pigeon pea treatment (OT-10) (0.607 ± 0.012 cm/day). High laccase activity was observed for P. lecomtei grown in starchy grain + moringa + pigeon pea substrate, reaching an activity of 416.8 ± 20.28 U/g. A. terreus growth in ST-09 (sorghum + pigeon pea) showed higher protein (15.3 ± 0.46%), β-glucan (503.56 ± 8.6 mg/g) and lovastatin (1.10 ± 0.17 mg/g) content compared to untreated substrates. These results demonstrate that filamentous fungi are an alternative for nutraceutical enrichment of ruminant feed biomasses. To the best of our knowledge, this is the first report in which P. lecomtei and F. hepatica are evaluated for their ability to be cultivated in ruminant feed substrates from Brazil.

Effect of Stone Crusher Dust Pollution on Biomass of Pigeon Pea

Stone crusher dust produces deleterious effects on growth and development of plants. This study was done on pigeon pea plants grown on different agro-climatic conditions of Nawada district of Bihar to evaluate the effect of stone crush pollution on its biomass. This study was done on samples collected at an interval of 30 days for up to 240 days. Five plants from each group were collected at each time point. The stem and root of the collected samples were evaluated for biomass. At the initial time point, we did not observe any significant difference in biomass in both stem and root among the study groups. However, we observed significantly decreased biomass in both stem and root in plants in the affected area compared with the unaffected area at later time points (90 days onward). Stone crusher dust may affect the plants through encrustation of leaves, plugging of stomata, changes in the quantum of light absorbed by leaves, changes in pH both outside and inside the leaf as well as through modification in soil condition. Further, the significantly reduced biomass may be due to inhibition of the metabolic activity of plants in affected areas. The present study gives the evidence to the fact that stone crusher dust pollution is harmful to pigeon pea plants off all ages, irrespective of the stage of growth and development.

Medicinal Uses, Nutraceutical Potentials and Traditional Farm Production of Bambara Beans and Pigeon Pea


 Bambara groundnut (BGN) [Vigna subterranean (L) Verdc] and Pigeon pea [Cajanus cajan (L.) Millspaugh] are grain legume species grown in tropical and subtropical parts of the world. Both legume grains are highly nutritious and have been used as food and medicine for both humans and animals. However, Bambara groundnut and pigeon pea are still highly underutilized and produced in low quantities despite their nutritional benefits. This review examines nutritional properties, medicinal uses, nutraceutical potential and the limitations in the utilization of bambara groundnut and pigeon pea. Scholarly articles and organization white papers were searched for using various word combinations of traditional farm practices, modern agricultural practices, traditional medicinal uses, nutritional composition, biochemical composition, Bambara groundnut and pigeon pea. Bambara groundnut and pigeon pea are popularly used as medicine in many parts of Africa. Both species are rich sources of bioactive compounds and several studies have documented their efficacy against several diseases. Bambara groundnut has been used to treat polymenorrhea, venereal diseases, cataracts, and morning sickness. The stem, leaves, seeds, and roots of pigeon pea plant has been used to treat many diseases in many parts of the world. Bambara groundnut has been found to be a potential dietary probiotic, antioxidant, antibiotic and anticancer. Hypocholesterolemic, anticancer, hepatoprotective, antidiabetic and antimicrobial activities have been documented for pigeon pea as well. However, low yield, unfavourable land tenure systems, unimproved varieties, diseases, and pests are the major constraints of the traditional production of bambara groundnut and pigeon pea. Both legume grain species are important sources of nutrients and they both possess strong potentials to be nutraceutical agents against many diseases including malnutrition. However, advanced and intensive research on pest management, improvement of the traditional landrace cultivars for improved yield and palatability as well as formulation of favourable land tenure policies are recommended for better adoption, utilization and commercialization of bambara groundnut and pigeon pea.

Electrophysiological and behavioral responses of blister beetle Mylabris pustulata to plant volatiles

Abstract Plant volatiles, constitutive or induced, are perceived by insect pests to locate the host plant and also by natural enemies to locate the host insect. These plant volatiles can be utilized to develop attractive or repellant lures for pest management. Studies were carried out to identify the plant volatiles which are induced in pigeonpea, Cajanus cajan (L.) Huth due to the herbivory of blister beetle, Mylabris pustulata. The volatiles from healthy uninfested pigeonpea plants and blister beetle-infested plants were collected using the dynamic headspace collection method with Porapaq Q (80-100 mesh) as adsorbent. Using gas chromatography-mass spectrometry, 28 compounds were identified from uninfested pigeonpea plants whereas 16 compounds were identified from infested plants. A qualitative analysis showed that α-pinene and 3-hexen-2-one were exclusively detected in infested plants and (Z)-3-hexen-1-yl acetate and acetophenone were released in higher quantities from infested plants than from uninfested one. Electrophysiological evaluation of these volatiles along with other plant volatiles showed that blister beetle antennae eliciting higher responses to eucalyptol at a 1-μg dose, to nerol at a 10-μg dose and to benzyl acetate at 100- and 1000-μg doses. Beetle traps with lures of eucalyptol, benzaldehyde, benzyl acetate, and nerol attracted a very small number of blister beetle adults, suggesting the need for further efforts to standardize lure load and trap design.