Pigeon Pea Seeds Research Articles

Zinc delivery to plants through seed coating with nano-zinc oxide particles

ABSTRACTIn India, zinc (Zn) has been recognized as the fourth most important yield-limiting nutrient after nitrogen (N), phosphorus (P) and potassium (K). Supplementing the zinc (Zn) requirement of agricultural crops through water soluble zinc sulfate ZnSO4 fertilizer is a costly management option whereas, utilization of ZnO (water insoluble and a cheaper material) as a source of Zn could be an alternative cost effective option to encourage farmers for wider adoption. In this present investigation, in order to supply the requisite amount of Zn to the plants, a protocol has been developed to coat the seeds of maize (Zea mays L.), soybean (Glycine max L.), pigeon pea (Cajanas cajan L.) and ladies finger (Abelmoschus esculentus L.) with microns scale (<3 µm) and nano-scale (<100 nm) ZnO powder at 25 mg Zn/g seed and at 50 mg Zn/g seed. Different Zn sources, ethyl alcohol, and crude pine oleoresin (POR) were used for coating of seeds. The germination test carried out with coated and uncoated seeds indicated better germination percentage (93–100%) due to ZnO coating as compared to uncoated seeds (80%). Pot culture experiment conducted with coated seeds also revealed that the crop growth with ZnO coated seeds were similar to that observed with soluble Zn treatment applied as zinc sulfate heptahydrate (ZnSO4·7H2O) (at 2.5 ppm Zn) which is evident from the periodic SPAD reading taken after 20, 25, 30 and 45 days after sowing. Application of Zn through different sources also enhanced the auxin indole-3-acetic acid (IAA) production in plant roots, which subsequently improved the overall growth. The most important advantage of seed coating with ZnO (both micron/nano-scale) is that it did not exert any osmotic potential at the time of germination of the seed, thus, the total requirement of Zn of the crop can be loaded with the seed effectively through nano-scale ZnO particle.

Effects of hormonal priming on seed germination of pigeon pea under cadmium stress.

In this work we investigated whether priming with auxin, cytokinin, gibberellin, abscisic acid and ethylene, alters the physiological responses of seeds of pigeon pea germinated under water and cadmium stress. Seeds treated with water or non-treated seeds were used as control. Although compared to non-treated seeds we found that the hormone treatments improve the germination of pigeon pea under cadmium stress, however, these treatments did not differ from water. However, we also observed a trend of tolerance to the effects of cadmium in the presence of ethylene, suggesting that the use of this hormone may be an efficient method to overcome seed germination under metal stress.

Response of Germination Physiology ofCajanus cajanSeeds to Drought Stress: Comparison Between Karst Water and Allogenic Water Treatments

In this paper, responses of germination physiology of pigeon pea (Cajanus cajan) seeds to drought stress in karst water environment and non-karst (allogenic) water environment were studied to explore the adaptability of pigeon pea to karst environment. The results showed that: (i) Under drought stress of 20% PEG-6000, the germination rate, vigor index, germination index and biomass of pigeon pea seeds on day 7 cultivated with karst water were all greater than that of the allogenic water treatment group, while the seed germination stress index was significantly smaller than that of the allogenic water treatment group, suggesting that karst water environment was more favorable to pigeon pea seed germination, (ii) Without drought stress, the malondialdehyde (MDA) and superoxide dismutase (SOD) activities of pigeon pea seeds cultivated with karst water were all smaller than that of the allogenic water group. However, under drought stress, the SOD activity was significantly higher than that of allogenic water group, suggesting pigeon pea SOD in karst water was able to more rapidly respond to external drought stress, and increase its own activity to reduce the damage to the plants. And (iii) with and without drought stress, the soluble protein level of the karst water group was higher than that of the allogenic water group, while the free amino acid level was lower than that of the allogenic water group. This difference was more significant with the presence of drought stress, suggesting that the karst water environment was more favorable to the accumulation of soluble proteins and thus produced larger biomass. Hence, pigeon pea is a tree species that is adapted to high-calcium, alkaline environments in karst areas, and is of great significance for the revegetation and rocky desertification control in mountainous karst areas.

A bifunctional α-amylase/trypsin inhibitor from pigeonpea seeds: Purification, biochemical characterization and its bio-efficacy against Helicoverpa armigera

This paper evaluates α-amylase inhibitor (α-AI) mediated defense of pigeonpea against Helicoverpa armigera. A bifunctional α-amylase/trypsin inhibitor was purified from the seeds of pigeonpea by native liquid phase isoelectric focusing (N-LP-IEF), affinity chromatography and preparative electrophoresis. Its in-vivo and in-vitro interaction with midgut amylases of H. armigera was studied along with growth inhibitory activity. One and two dimensional (2D) zymographic analyses revealed that the purified inhibitor is dimeric glycoprotein (60.2kDa and 56kDa) exist in a multi-isomeric form with five pI variants (pI 5.5 to 6.3). It was found to be heat labile with complete inactivation up to 80°C and stable over a wide range of pH (4–11). The slow binding and competitive type of α-amylase inhibition was observed with 0.08μM of dissociation constant (Ki) for the enzyme–inhibitor complex (EI). The internal protein sequence of two subunits obtained by mass spectrometry matched with cereal-type α-AI, a conserved domain from AAI_LTSS superfamily and sialyltransferase-like protein respectively. In-vivo studies indicated up-regulation of total midgut α-amylase activity with negative effect on growth rate of H. armigera suggesting its suitability for pest control.

Dietary Effects of Increasing Levels of Pigeon Pea Meal on Rabbit Performance

Conventional feedstuffs in Nigeria are expensive, which has led to the search for cheap and locally available unconventional feeding materials. This study was therefore conducted to determine the dietary effect of roasted pigeon pea meal (RPP) on the performance of rabbits. A total of forty weaner rabbits (20 male and 20 female) Dutch × Chinchilla rabbits with an average initial weight of 725 g and between 5 and 7 weeks old, were allocated into four dietary treatments. Each treatment had ten rabbits and five replicate per treatment in a completely randomized design. The process of roasting pigeon pea seeds took 3 to 5 minutes at approximately 80 oC. The roasted pigeon pea meal (RPP) was used in formulating the diets used for rabbits. Treatment 1 (control) was maize-soybean based diet with 0% RPP while the other treatments contained 10, 20 and 30% RPP in the diets respectively. Diets were formulated to be isonitrogenous and isocaloric. The experiment lasted for five weeks during which data were recorded for feed intake and body weight. The daily feed intake ranged from 42.26 to 57.60 g; daily weight gain, 12.27 to 15.70 g; feed conversion ratio, 3.41 to 4.67 and final live weight, 1284.00 to 1434.75 g. None of these performance parameters were significantly affected by dietary treatments. It was therefore concluded that roasted pigeon pea (RPP) can successfully be included up to 30% in the ration of rabbits without adversely affecting performance.

Total phenols, total flavonoids contents and free radical scavenging activity of seeds crude extracts of pigeon pea traditionally used in Oman for the treatment of several chronic diseases

ObjectiveTo investigate total phenols, flavonoids content of methanol crude extract of pigeon pea seeds powder and its different polarities soluble fractions and evaluate their free radical scavenging activity. MethodsThe powder seeds samples were used for extraction with methanol. Methanol crude extract from the seeds was defatted by water and fractioned by different polarities of solvents. The investigation of total phenols and flavonoids contents of total six crude extracts of pigeon pea were determined by Folin-Ciocalteu reagent and aluminum chloride calorimetric methods. Antioxidant activity of six crude extracts from the seeds of pigeon pea was determined through α,α-diphenyl-β-picrylhydrazyl method. ResultsSignificant amount of total phenols content was presented in hexane crude extract among the six crude extracts of pigeon pea and the order was hexane>chloroform> methanol>ethyl acetate>butanal>water. Similarly, significant amount of total flavonoids content was presented in chloroform crude extract and the order was chloroform>methanol>ethyl acetate>butanol>water>hexane. The crude extracts displayed significant α,α-diphenyl-β-picrylhydrazyl free radical scavenging activity with highest value in hexane extract followed by butanol, methanol, ethyl acetate, chloroform and water crude extracts having value of 95.50%, 83.30%, 64.60%, 64.20%, 60.60% and 52.60%, respectively. ConclusionsThe crude extracts from seeds of pigeon pea have high contents of total phenols, flavonoids and antioxidant activity. In this regards, it could be used as a medicine for the treatment of different chronic diseases.

Growth Performance of Broiler Chickens Fed Raw and Processed Pigeon Pea (Cajanus Cajan) Seed Meal

The present study was conducted to determine the growth performance of broilers fed raw and processed Pigeon pea (Cajanus Cajan) seed meal. Sixty day old Anak broiler chicks were randomly assigned to four experimental diets containing raw (RPPSM), boiled (BPPSM), toasted (TPPSM) and soaked (SPPSM) pigeon pea seed meal at 25% inclusion level in a Completely Randomize Design. There were 15 birds per treatment group and each treatment was replicated three times with five birds per replicate. Parameters measured were body weight, feed intake, carcass and organ weights. Body weight gain (BWG), and feed conversion ratio (FCR) were calculated. Results showed significant (P<0.05) differences in growth performance among birds in the different treatment groups. Birds fed boiled pigeon pea seed meal (BPPSM) exhibited better growth performance and feed conversion ratio than birds in other treatment groups while those fed soaked pigeon pea seed (SPPSM) showed the least growth performance. Carcass analysis showed significant (P<0.05) differences in carcass and heart weights but not in gizzard, and liver weights and dressing percentage. It was therefore concluded that boiling was the best method to eliminate the anti-nutritional factors in pigeon pea seeds proposed for use in broiler diets.

Physiological Quality of Pigeonpea Seed after Application of Desiccant Herbicides

The pre-harvest application of herbicides may impair seed quality. This way, this paper was conducted to evaluate the effects of the application of desiccant herbicides on the physiological quality of pigeonpea seeds. Six batches of seeds from plants desiccated with glyphosate were evaluated at doses: 1.125 (B1), 1.5 (B2) and 1.875 Lm and Gramocil (20% Paraquat + 10% Diurom) at doses: 1.5 (B4) and 2 Lm b) applications of glyphosate in a 1.875 Lm and c) the seed vigor measured by the first count, seedling length, seedling dry matter and biomass density test was not influenced by the type of desiccant applied.

Assessment of Protein Content and Study Effect of Anti-Nutrition Factor on in-vitro Protein Digestibility

Aims of this study were assessed the protein content of dry meat, raw egg, dehulled seeds of wheat, pigeon pea and study effect of concentration 1, 2 and 3% of the Pure Tannin, Solenostemma argel, Artemisia herba alba , Process green tea and Moringa oleifera on in-vitro protein digestability of animal and plant protein. Experiment: It was carried out in lab of Department of Food Science and Technology, Faculty of Agriculture, University of Khartoum in 2014. Methodology: Micro-Kjeldhal method and in-vitro protein digestability were used. Results: Results indicated that protein content of dry meat (77%) and raw egg (79%) was higher than protein content of dehulled seeds of wheat (18%) and dehulled seeds of pigeon pea (22%). There was significant difference between the four samples in protein at P ≤ 0.05. In-vitro protein digestability of dry meat, raw egg, dehulled seeds of wheat and pigeon was clearly reduced with increasing the concentration of pure tannin. While in-vitro protein digestability for dehulled wheat was clearly increased with increasing the concentration of S . argel leaves, but no significant was observed in dehulled seeds of pigeon pea, but at concentration 3% S. argel, the in-vitro protein digestability was decreased. In case of dry meat and raw egg in-vitro protein digestability was reduced with adding 1, 2 and 3% S. argel leaves. Whereas, in-vitro protein digestability for dehulled seeds of wheat was improved with increasing concentration of S. argel , but in-vitro protein of dehulled pigeon pea was decreased with increasing concentration of S. argel . While in-vitro protein digestability for dry meat, raw egg, dehulled seeds of wheat and pigeon pea was reduced with increasing concentration of A. herba alba , process green tea and M. oleifera , but at concentration 3% of moringa the in-vitro protein digestability of dehulled seeds of pigeon pea (75%) was improved. Conclusion: Protein content is very rich in animal products, but it is very poor in plant products. Uses of S. argel with dehulled seeds of wheat was improved its in-vitro protein digestability, but uses of pure tannic acid, A. herba alba and green tea reduced in-vitro protein digestability.

Physiological deterioration of pigeon pea seeds during storage

The pigeon pea appears as a good option for farmers to be used directly in food and feed and/or green manure. In spite of this potential, its cultivation area in our conditions is still incipient, mostly due to the lack of seeds of superior quality. It is known that the process of physiological deterioration of seeds varies according to species, constituting a relevant factor in seed technology. Storage problems in Brazil are still an issue and the decrease of physiological quality of seeds at this stage is considerable, especially for seeds containing high concentrations of protein (> 22%) as for the pigeon pea. In this context, this study aimed to evaluate the physiological deterioration of pigeon pea seeds stored in different containers and environments for 10 months. The completely randomized design in a factorial 2 × 4 × 6 with four replications was used. The treatments were constituted of two storage environments (natural condition of laboratory (25 ± 2°C) and refrigerator (4 ± 2°C), combined with four types of packaging (PET bottle, plastic bag, burlap bag and kraft paper) and six storage periods (0, 2, 4, 6, 8, 10 months). The physiological seed quality was determined in a timeframe of two months by the following tests: Standard Test Germination - TPG, TPG first count, accelerated aging and electrical conductivity. It is concluded that the percentage of normal germination seedlings by TPG decreases linearly along the storage period; the PET bottle and Plastic bag preserved the vigor and viability of the seeds more efficiently along the storage, being that the PET bottle for being waterproof and tightly sealed has obtained better performance; and the refrigerator-controlled environment is the most suitable for storage of the pigeon pea among the tested environments. Key words: Cajanus cajan L., seed quality, physiological deterioration, preservation, packaging.

In vivo evaluation of two essential oil based botanical formulations (EOBBFs) for the use against stored product pathogens and pests, Aspergillus species and Callosobruchus species (Coleoptera: Bruchidae)

Laboratory bioassays were conducted to evaluate the comparative efficacy of two essential oil based botanical formulations (EOBBFs) made from 1, 5 and 10% concentrations of Chenopodium ambrosioides and Clausena pentaphylla essential oils for the storage of pigeon pea seeds. C. ambrosioides and C. pentaphylla oils were formulated as bioproduct A and B respectively. During in vivo evaluation of both bioproducts against the fungi (Aspergillus flavus, A. niger, A. ochraceus and A. terreus) of pigeon pea seeds for six months; bioproduct A was more potent than bioproduct B, with 85.2–96.4% percent protection of seeds from fungal contamination. When Callosobruchus chinensis and C. maculatus adults were exposed to bioproducts A and B for 72 h (28 ± 2 °C and 75 ± 5% r.h.), significant mortality (P < 0.05) of the test insects was observed. 100% mortality of both insects was achieved by 5 and 10% of bioproduct A and 10% of bioproduct B. Both the bioproducts at different dosages (1, 5 and 10%) significantly reduced oviposition and adult emergence of C. chinensis and C. maculatus in treated pigeon pea seeds. Furthermore, in vivo fumigant efficacy tests against these insects on pigeon pea seeds revealed that both bioproducts significantly protected 1 kg of seeds for up to six months. Both EOBBF enhanced feeding deterrency and so reduced the seed damage as well as weight loss in fumigated seed samples. Both EOBBFs were non-phytotoxic regarding the germination of pigeon pea seeds. Sensory evaluation revealed that appearance, tenderness, flavour, taste, colour and overall acceptability were significantly higher in fumigated seeds than non-fumigated ones after 6 months of storage. It was concluded that after multilocation field trials, the bioproducts may be formulated and commercialized as substitutes for synthetic fumigants for safe storage of pigeon pea seeds and other food commodities.

Effect of Variable Physical Factors on the Toxicity of Plant Volatiles Against Some Aspergillus Spp.

The objective of the present study is to investigate the effect of physical factors on mycotoxic potency of Chenopodium ambrosioides Linn. and Clausena pentaphylla (Roxb.) DC oils against four species of Aspergilli such as A. flavus Link, A. niger van Tieghem, A. ochraceus Wilhelm, A. terreus Thom causing post-harvest deterioration of pigeon pea seeds. During experimentation it was observed that the potency of both oils remained unchanged even against heavy inoculum dose (maximum number of 10 fungal discs and diameter of 25 mm). Furthermore, the toxicity of both the oils did not alter even up to 120 ºC of temperature and 12 months of storage by exhibiting 100% mycelial inhibition of test fungi. The toxicity of both the oils was decreased at alkaline pH (7, 8). Physicochemical characterization of oils revealed that C. ambrosioides oil was pale yellow in colour, lighter than water, laevorotatory, acidic in nature and showed positive test for phenols. While the oil of C. pentaphyllahad light pale color, dextrorotatory, slightly acidic and showed presence of phenols. Both the oils showed good solubility in various organic solvents

Mutagenic Effect on Seed Germination, Seedling Growth and Seedling Survival of Pigeon Pea (&lt;i&gt;Cajanus cajan&lt;/i&gt; (L.) Millsp)

In the present investigation the seeds of Pigeon pea (Cajanus cajan (L.) Millsp) were treated with different doses of gamma radiation (05KR, 10KR, 15KR, 20KR, 25KR, 30KR, 35KR, 40KR, 45KR, and 50KR) and concentration of Ethyl Methane Sulphonate (05mM, 10mM, 15mM, 20mM, 25mM, 30mM, 35mM, 40mM, 45mM, and 50mM) for studying seed germination, seedling height, (shoot and root), seedling injury, seedling vigour index, and seedling survival of plants at 30th day. The seed germination percentage was decreased with increased in the concentration/doses when compared to control. The LD50 (Lethal dose) value was determined based upon the seed germination percentage. The 50 percentage of seed germination and reduction was observed in 20KR of gamma rays and 25mM of EMS and it is considered as LD50 value for both the treatments. The decrease in seed germination was more prominent with gamma rays than that of EMS treatments. The seedling parameters of gamma rays and EMS treated seedlings were progressively decreased with increase dose/concentration in all mutagenic treatments when compared to control. The maximum seedling parameters were observed in 05KR of gamma rays and 05mM of EMS. Minimum seedling parameters were observed in 50mM of EMS and 50KR of gamma rays respectively.

Mutagenic Effect on Seed Germination, Seedling Growth and Seedling Survival of Pigeon Pea (&lt;i&gt;Cajanus cajan&lt;/i&gt; (L.) Millsp)

In the present investigation the seeds of Pigeon pea (Cajanus cajan (L.) Millsp) were treated with different doses of gamma radiation (05KR, 10KR, 15KR, 20KR, 25KR, 30KR, 35KR, 40KR, 45KR, and 50KR) and concentration of Ethyl Methane Sulphonate (05mM, 10mM, 15mM, 20mM, 25mM, 30mM, 35mM, 40mM, 45mM, and 50mM) for studying seed germination, seedling height, (shoot and root), seedling injury, seedling vigour index, and seedling survival of plants at 30th day. The seed germination percentage was decreased with increased in the concentration/doses when compared to control. The LD50 (Lethal dose) value was determined based upon the seed germination percentage. The 50 percentage of seed germination and reduction was observed in 20KR of gamma rays and 25mM of EMS and it is considered as LD50 value for both the treatments. The decrease in seed germination was more prominent with gamma rays than that of EMS treatments. The seedling parameters of gamma rays and EMS treated seedlings were progressively decreased with increase dose/concentration in all mutagenic treatments when compared to control. The maximum seedling parameters were observed in 05KR of gamma rays and 05mM of EMS. Minimum seedling parameters were observed in 50mM of EMS and 50KR of gamma rays respectively.

Effect of Different Auxin Concentration on Rooting in Pigeonpea (Cajanus cajan [L.] Millsp.) cv. Manak (H77216) ViaCotyledonary Node Explants

Pigeonpea ( Cajanus cajan [L] Millsp.) is an important grain legume of the semi-arid tropics. It provides protein rich food. Seeds of pigeonpea were collected and surface sterilized, these sterilized seeds were germinated aseptically in shoot induction media (SIM) fortified with MS media supplemented with 2mg/l BAP. Cotyledonary node explants (excised from 15 day old seedlings) were transferred to shoot elongation media (SEM) for elongation fortified with MS media + 1.0 mg/l GA 3. Elongated shoots were transferred to root induction media (RIM) using different concentration of IAA and IBA. Highest percentage (93) of rooting was observed on modified MS media + 1.0 mg/l IBA.

Influence of Host Origin on Host Choice of the ParasitoidDinarmus basalis: Does Upbringing Influence Choices Later in Life?

The aim of this study was to investigate the influence of volatile compounds from four secondary host plants on the ability of Dinarmus basalis Rond. (Hymenoptera: Pteromalidae) to locate, recognize, and parasitize its host, 4th instar larvae or pupae of Callosobruchus maculatus F. (Coleoptera: Chrysomelidae). To examine this, strains of D. basalis were transferred from cowpea seeds (Vigna unguiculata (L.) Walp. (Fabales: Fabaceae)) to pigeon pea (Cajanus cajan (L.) Millsp.) and two varieties of Bambara groundnut (Vigna subterranea (L.) Verdc.) seeds. The ability of D. basalis females to recognize the volatile compounds emanating from their complex host plant was tested by using a Y-tube olfactometer and a three-dimensional device. The results suggest that when females have a choice between pure air and the air emanating from their complex host of origin, they are attracted to the air tainted by the volatile compounds they have become accustomed to. They spent significantly more time (p < 0.0001) in the branch of the tube leading to the odorous air than in the tube leading to the pure air. When females from pigeon pea seed hosts were offered a choice between cowpea and pigeon pea seeds, all containing 4th instar larvae, the familiar odor of pigeon pea seeds were most attractive. When females from Bambara groundnut (white and striped) seed hosts were offered a choice between cowpea and pigeon pea seeds, all containing 4th instar larvae, they were significantly attracted to the odour of cowpea seeds. In the three-dimensional system, the females from the four strains did not appear to have any preference for a given type of seed containing 4th instar larvae or pupae. The parasitism rate remained high on all four types of seeds used. These results show that the use of D. basalis as a biological control agent is possible in host changing situations where C. maculatus starts to attack other legumes. The results of this study also provide information supporting the behavioral plasticity of D. basalis. Understanding the mechanisms involved in the adaptive phenomena of biological control agents is discussed in the context of the development of adequate methods of pest control.

Influence of host origin on host choice of the parasitoid Dinarmus basalis: does upbringing influence choices later in life?

The aim of this study was to investigate the influence of volatile compounds from four secondary host plants on the ability of Dinarmus basalis Rond. (Hymenoptera: Pteromalidae) to locate, recognize, and parasitize its host, 4 th instar larvae or pupae of Callosobruchus maculatus F. (Coleoptera: Chrysomelidae). To examine this, strains of D. basalis were transferred from cow-pea seeds ( Vigna unguiculata (L.) Walp. (Fabales: Fabaceae)) to pigeon pea ( Cajanus cajan (L.) Millsp.) and two varieties of Bambara groundnut ( Vigna subterranea (L.) Verdc.) seeds. The ability of D. basalis females to recognize the volatile compounds emanating from their complex host plant was tested by using a Y-tube olfactometer and a three-dimensional device. The results suggest that when females have a choice between pure air and the air emanating from their com-plex host of origin, they are attracted to the air tainted by the volatile compounds they have become accustomed to. They spent significantly more time ( p < 0.0001) in the branch of the tube leading to the odorous air than in the tube leading to the pure air. When females from pigeon pea seed hosts were offered a choice between cowpea and pigeon pea seeds, all containing 4 th instar larvae, the familiar odor of pigeon pea seeds were most attractive. When females from Bambara groundnut (white and striped) seed hosts were offered a choice between cowpea and pigeon pea seeds, all containing 4 th instar larvae, they were significantly attracted to the odour of cowpea seeds. In the three-dimensional system, the females from the four strains did not appear to have any preference for a given type of seed containing 4 th instar larvae or pupae. The parasitism rate remained high on all four types of seeds used. These results show that the use of D. basalis as a biological control agent is possible in host changing situations where C. maculatus starts to attack other legumes. The results of this study also provide information supporting the behavioral plas-ticity of D. basalis . Understanding the mechanisms involved in the adaptive phenomena of biological control agents is discussed in the context of the development of adequate methods of pest control.

Purification and Characterization of Glucose-6-Phosphate Dehydrogenase from Pigeon Pea (Cajanus cajan) Seeds

Glucose-6-phosphate dehydrogenase has been purified from pigeon pea (Cajanus cajan) seeds and subjected to characterization. The enzyme was purified 123.69 fold with a yield of 21.37% by ammonium sulphate fractionation, PEG-4000 precipitation, CM cellulose column chromatography and DEAE cellulose column chromatography. The catalytically active enzyme is a dimer of 113 KDa with a subunit molecular weight of 55 KDa. Thermal inactivation of enzyme follows first order kinetics at 30&#176C and 40&#176C with half life of 6 and 1.5 min respectively. Km value for glucose-6-phosphate and NADP+ was found to be 2.68 mM and 0.75 mM respectively whereas Vmax value was found to be 0.11 U/mL and 0.13 U/mL respectively. The enzyme shows more affinity towards NADP+ than glucose-6-phosphate. The pKa value was found to be 10.41 indicating that the amino acid residue at active site might be lysine. The enzyme exhibited maximum catalytic activity at pH 8.2. The enzyme was found to be highly thermosensitive with gradual loss of activity above 30&#176C temperature.

Analysis of sequential accumulation of individual pigeonpea protease inhibitors during seed development

Seeds of pigeonpea are known to accumulate protease inhibitors (PIs), belonging to the Bowman-Burk inhibitor family. PIs are important for natural defense against phytophagous insect pests. Most insects attack crops at the early stages of seed development. Accumulation patterns of individual PIs and their relationship with each other were studied in developing seeds of 76 pigeonpea lines derived from BDN2 cultivar by ethyl methane sulfonate induced chemical mutagenesis. PIs extracted from these lines, collected between 10 and 40 days after flowering (DAF) and from mature seeds of BDN2 cultivar, were detected by using gel X-ray film contact print method. A total of 9 trypsin–chymotrypsin inhibitors were detected in mature seeds. All the nine PIs were capable of inhibiting proteases. Appearance of detectable levels of individual PIs started around 10 DAF. The PI-3 appeared early and was the most stable. It was accumulated in all the studied lines and was also detected in 84 % of the samples collected 10 DAF. In particular, 14 DAF, the individual PIs were accumulated and accumulation sequence was observed (PI-3, PI-2, PI-5, PI-7, PI-6, PI-4, PI-8, PI-9 and PI-1). Accumulation continued up to 40 DAF when seeds started hardening. Chemical mutagenesis could not produce any variation in the profile of individual PIs in the 76 studied lines in mature seeds. The process of accumulation of inhibitors is sturdy and mutagenesis fails to alter it. The robust mechanism is responsible for early appearance of PI-3. Early accumulated PIs in this study need further exploration for strengthening natural defense of pigeonpea against pests.

Application of Chenopodium ambrosioides Linn. essential oil as botanical fungicide for the management of fungal deterioration in pulses

Essential oils isolated from 35 aromatic plants of Gorakhpur Division, India, were screened at 0.36 μl ml− 1 against four dominant fungi Aspergillus flavus Link, A. niger van Tieghem, A. ochraceus Wilhelm and A. terreus Thom found on stored pigeon pea (Cajanus cajan Linn.) seeds. Chenopodium ambrosioides Linn. and Citrus aurantium Linn. oils exhibited strong antimycotic activity (100% mycelial inhibition). The minimum inhibitory concentration of C. ambrosioides oil was less (0.07 μl ml− 1) than that of C. aurantium oil, against all the test fungi. Both the oils were fungicidal at higher doses (1.71–2.78 μl ml− 1). C. ambrosioides oil exhibited broad fungitoxic spectrum against 16 other storage fungi of pigeon pea seeds. The oil remained effective with increased inoculum load, and physical factors had no adverse effect on its toxicity. C. ambrosioides oil proved superior to aluminium phosphide and ethylene dibromide, synthetic fumigants, at 0.29 μl ml− 1 and significantly protected 1 kg of pigeon pea seeds from microbial attack for up to 6 months. Chenopodium oil can be recommended as an effective substitute of synthetic fumigants for storage of pigeon pea seeds.