Nilotica Seeds Research Articles

Toxicity, biochemical and molecular docking studies of Acacia nilotica L., essential oils against insect pests

Botanical essential oils are natural insecticides derived from plants, offering eco-friendly alternatives to synthetic chemicals for pest control. In this study, the essential oils were extracted from Acacia nilotica seed cotyledons, and their toxicity was tested against insect pests. Furthermore, the chemical components of the essential oils were identified through gas chromatography-mass spectrometry (GC-MS) analysis. The essential oil extracted from A. nilotica seeds exhibited the highest mortality rates of 60% and 98% in Culex quinquefasciatus, and 60% and 96.66% mortality in Plutella xylostella at 24 and 48 h after treatment, respectively. The essential oils resulted in a lower LC50 of 159.263 ppm/mL, and LC90 of 320.930 ppm/mL within 24 h. In 48 h, the LC50 was 52.070 ppm/mL and the LC90 was 195.123 ppm/mL for C. quinquefasciatus. In the essential oil treatment of P. xylostella, the lower LC50 was 165.900 ppm/mL, and the LC90 was 343.840 ppm/mL 24 h after the treatment. At 48 h post-treatment, the LC50 decreased to 62.965 ppm/mL, and the LC90 decreased to 236.795 ppm/mL in P. xylostella. The study investigated the impact of essential oils on insect enzymes 24 h after treatment. The study revealed significant changes in the levels of insect enzymes, including a decrease in acetylcholinesterase enzymes and an increase in glutathione S-transferase compared to the control group. Essential oils had minimal effects, resulting in mortality rates of 30.66% and 46% at 24 and 48 h after treatment on Artemia salina. After 48 h, minimal toxic effects of essential oils were observed on E. eugeniae, with a mortality rate of 11.33%. The GC-MS analysis of A. nilotica seed-derived essential oils revealed ten major chemical constituents, including 6-hydroxymellein, phthalic acid, trichloroacetic acid, hexadecane, acetamide, heptacosane, eicosane, pentadecane, 1,3,4-eugenol, and chrodrimanin B. Among these constituents, Heptacosane is the major chemical component, and this molecule has a high potential for involvement in insecticidal activity.

Reviving the Resilient: Exploring Pre-Dormancy Breaking Treatments for Acacia nilotica (L.)

Acacia nilotica plays an important ecological role in its native habitats and has great relevance for restoration as well as in terms of economic worth. Acacia nilotica species frequently exhibit seed dormancy, which makes planting and seed testing difficult. In the present work, we examined the degree of dormancy and the impact of various pre-treatments on the dormancy breaking of Acacia species. Several tests were carried out against this backdrop to standardize the mechanical scarification, seed priming, and coating techniques. The results showed that mechanical scarification of Acacia nilotica seeds with @6 min scarification improved the seed germination percentage and vigour index percentage by 117 and 184 percent over the control. Correspondingly, the application of the TNAU seed coating formulation on Acacia nilotica seeds at 2g kg-1 increased the germination percentage and vigour index percentage by 129 and 186 percent, respectively, over the control. Also, humid priming of Acacia seeds (12 h soaking in water + 2 days humid incubation) resulted in a gradual increase in the seed germination percentage and vigour index percentage by 181 and 263 percent over the control. The seeds were not harmed by any of these treatments, which all reduced hard seeds to zero and improved germination percentages.

The Potential for Endozoochorous Dispersal of Vachellia nilotica Seeds by Goats: Implications for Bush Encroachment

Seed dispersal has become an important component in understanding plant–animal interaction. Recently, there have been concerns about the role of ruminants, particularly browsers, in the dispersal of woody plant seeds. This study aimed to determine whether including Vachellia nilotica seeds in livestock, diets could reduce the spread of viable seeds in the rangelands and control bush encroachment. The shoots and seed pods of Vachellia nilotica were harvested and analyzed for fiber, protein, and mineral nutrients at different seed pods inclusion rates, with or without a feed additive. Six diets were selected for feeding 24 goats and quantifying seed recovery and germination after ingestion. Results indicated that including seed pods and feed additives to Vachellia nilotica shoots significantly improved the quality of the fodder. Chipping the seed pods prior to including them in the diet resulted in 13% intact seed recovery, and approximately 2% of these seeds were recovered after ingestion. These recovered seeds were mostly still viable but were still dormant as seed coats were not sufficiently damaged after ingestion. Therefore, viable seeds may still be dispersed in the rangeland, leading to further bush encroachment.

Essential oils from Acacia nilotica (Fabales: Fabaceae) seeds: May have insecticidal effects?

In the present study Acacia nilotica seed derived essential oils were tested against Spodoptera litura, Tenebrio molitor, Oxycarenus hyalinipennis, and Aphis fabae, as well as their effects on non-target species Eudrilus eugeniae and Artemia salina at 24 h post treatment. The seed essential oil produced insecticidal activity against A. fabae (LC50 = 41.679, LC90 = 75.212 μl/mL), O. hyalinipennis (LC50 = 37.629, LC90 = 118.485 μl/mL), T. molitor (LC50 = 56.796, LC90 = 201.912 μl/mL), and S. litura (LC50 = 62.215, LC90 = 241.183 μl/mL). Essential oils do not cause a remarkable effect on E. eugeniae and A. salina cytotoxicity. The essential oils produced a lower effect on Artemia salina (LC50 = 384.382, LC90 = 1341.397 μl/mL) and no lethal effects were observed on E. eugeniae. The histopathological evaluation showed no sub-lethal effects of essential oils on earthworm gut tissues. GC-MS analysis results revealed that the major chemical constituent was hexadecane (19.560%) and heptacosane (17.214%) and FT-IR analysis revealed the presence of alkanes and alkyles, aromatics, and amides functional groups that may be involved in insecticidal activity. Overall, the results showed that the seed derived essential oil has excellent insecticidal action against major agricultural insect pests and may therefore offer an environmentally benign alternative to conventional insecticide.

ISOLATION OF STIGMASTEROL AND GASTROPROTECTIVE ACTIVITY OF THE ETHYL ACETATE PORTION FROM ACACIA NILOTICA LINN (FABACEAE) SEEDS

Acacia nilotica Linn is used traditionally in the treatment of various diseases, such as diarrhea, ulcer, dysentery, asthma, inflammation and cancer. The present study aimed at isolation and characterization of a steroidal compound and evaluating the gastroprotective activity of the ethyl acetate portion of A. nilotica seeds in indomethacin-induced ulcer model. Fractionation of the ethyl acetate portion using standard chromatographic techniques led to the isolation of a compound (B2-I) which on further purification and characterisation using physical, chemical and spectral analysis, and by comparison with literature values was identified as stigmasterol. The effect of ethyl acetate portion of A. nilotica on experimentally induced ulcer was dose-dependent with curative ratios of 40%, 60% and 75% at concentrations of 100, 200 and 300 mg/kg body weights respectively. It significantly (P<0.05) decreased free and total acidity and increased the pH of gastric juice with respect to the indomethacin treated group. This justifies the ethnomedicinal use of A. nilotica seed as an antiulcer agent. The study recommends that A. nilotica seeds be evaluated against other ulcer models such as ethanol and stress induced ulcers.

Seed germination dynamics of some woody legumes: implication for restoration of arid zones ecosystems.

The seed germination dynamics of Acacia nilotica, Bauhinia rufescens, Faidherbia albida, and Piliostigma reticulatum were investigated over 28 days. Seeds were pretreated with concentrated sulfuric acid. Determined germination parameters included germination energy, germination period, germination capacity, germination inertia, and viability loss. Seeds exposed to sulfuric acid for extended periods (30, 40, 50, and 60 min) exhibited a higher germination rate (α = 0.05). For A. nilotica seeds, the 50 min acid treatment resulted in the highest germination energy of 85.5% and germination capacity of 89.5% (P = 0.001); conversely, the 60-min treatment yielded the highest germination energy and capacity, both 96.5% (P = 0.079), for P. reticulatum. In the case of B. rufescens, the 30-min treatment led to the highest germination energy of 93% and germination capacity of 88% (P = 0.001). For F. albida, all acid treatments resulted in 100% for both germination energy and germination capacity (P = 0.621). Viability losses for A. nilotica and P. reticulatum were higher (32 and 30%, respectively) than those for B. rufescens and F. albida, which were 19.5 and 6%, respectively (P = 0.000). Generally, higher germination energy resulted in lower viability loss, dependent on the species. Analyses of germination inertia and viability loss suggest that seeds of A. nilotica and P. reticulatum possess a greater ability to survive in arid land climates than those of B. rufescens and F. albida. However, due to the advantage of lower viability loss, B. rufescens and F. albida should be preferred for the natural restoration of arid land ecosystems where seed availability is a major concern.

Impact of Different Glomus Species on Growth and Survival of Acacia nilotica Seedlings

Acacia nilotica (L.) Willd. ex Del, commonly known as babul, kikar belongs to family Leguminosae and is recognized as a multipurpose tree. It helps in improving soil fertility, increasing the activity of symbiotic microorganisms and providing various commercial benefits. The raising of high quality kikar seedlings is necessary to establish a good plantation and the role of arbuscular mycorrhizal fungi (AMF) in soil becomes imminent in raising of seedlings under nursery. The effect of three different species of Glomus spp. (G. mosseae, G. intraradices and G. fasciculatum) of AMF inoculated soil with Acacia nilotica seeds were observed in the nursery during 2018-2019 and 2019-2020. These AMF were applied at 400-500 sporocarp/kg of soil at sowing time and evaluated for their performance on the growth parameters, survival percentage, root colonization (%) and number of sporocarps. The experiment was laid out as completely randomized design, replicated three times with twenty seedlings per replication. The results revealed that among three Glomus species, the shoot length of 60.75 (2018-2019) and 59.80 cm (2019-2020) was the significantly high in soils inoculated with G. intraradices as compared to check (uninoculated). The root length of seedlings was also significantly higher when seeds were sown in soil inoculated with G. intraradices followed by G. fasciculatum inoculated soil. The plant biomass was recorded significantly high when seeds were sown in soil infested with G. intraradices (23.77 g) followed by G. fasciculatum (21.57 g) and minimum in the G. mosseae (20.20 g) among Glomus spp. during 2019-2020. The seedlings survival was 81.53 and 85.79 % in soils inoculated with G. intraradices followed by 74.65 and 79.01 % in G. fasciculatum during 2018-2019 and 2019-2020, respectively and all the treatments differed significantly as compared to check. A significant higher root colonization (20.35 and 19.16 %) and number of sporocarps (28.0 and 26.51 /per 100 g of soil) at 150 DAS were recorded in soils inoculated with G. intraradices followed by G. fasciculatum.

Effects of Different Seeds Pretreatments on the Germination of Five Local Trees: Four From The Fabaceae Family and One From the Bombacacea

The problem of the effectiveness of the established pre-treatments of seeds of local tree species is posed more and more often, with acuity. It appears necessary that studies are led to explore new methods of pre-treatment, or to update the old instructions applied, for a better success and at lower cost, of the production of seedlings. The present study concerned five species: Acacia nilotica, Adansonia digitata, Parkia biglobosa, Piliostigma reticulatum and Tamarindus indica. The methodology involved subjecting the seeds to three different pretreatments: (i) seeds treated with sulfuric acid (T0), (ii) seeds soaked in hot water for 24 hours (T1), (iii) seeds soaked in hot water for 48 hours (T2). For Acacia nilotica seeds, the different pretreatments did not result in statistically different germination rates. The germination rates are 77%, 65% and 62% (respectively for soaking in hot water for 48 hours, sulfuric acid and soaking in hot water for 24 hours). The different pretreatments also do not result in different germination rates for Tamarindus indica. Indeed, the germination rates after 30 days for this species are good but statistically identical (85% for the pretreatment with sulfuric acid and hot water for 24 hours). For Adansonia digitata, Parkia biglobosa and Piliostigma reticulatum, the sulfuric acid pretreatment gave the best germination rate (49%, 54% and 41% respectively). The results of this study may have practical consequences in terms of management of the different species studied. They show that immersing in boiling water and left for 24 hours and 48 hours yields fairly satisfactory germination rates for Acacia nilotica and Tamarindus indica seeds. These inexpensive techniques, accessible to all, can be considered as means to easily produce seedlings of these species.

English

Acacia nilotica seed (ANS) and Parkia biglobosa seed (PBS) are underutilised legume found to have health benefits and functional properties. This study determined nutrient composition of A. nilotica and P. biglobosa seeds. ANS and PBS were collected and processed properly for chemical analysis. The proximate, minerals, vitamins, essential amino-acids, and antinutrient composition were analyzed to ascertain nutritional attributes and its potential in promoting dietary diversity. The raw and fermented A. nilotica seeds contained in g/100 g, protein (12.88 to 15.38), fat (3.29 to 4.91), ash (5.24 to 6.84), dietary fibre (1.98 to 2.66) and available carbohydrate (69.63 to 71.73), while the FPB contained in g/100 g, protein (18.30), fat (9.20), ash (8.69), dietary fibre (2.61), and available carbohydrate (56.27). The fermented A. nilotica (FAN) seed contained all the nine (9) essential amino acids. The raw and fermented ANS contained in mg/100 g, iron (9.67 to 12.23), zinc (0.69 to 1.13), calcium (0.17 to 0.22), sodium (0.14-0.21) while the FPB seed contained 14.86, 1.59, 0.25, and 0.24, respectively. FAN and FPB contained in µg/100 g, vitamin A (148.79 and 197.81), vitamin E (15.90 and 24.69) and vitamin K (1.41 and 1.63), respectively. The levels of antinutrient factors in all the samples were not significant. Fermented A. nilotica seed contained adequate level of some micronutrients and essential amino acids. Consumption of the seed should therefore be promoted. Key words: Nutrient composition, dietary diversity, underutilized legumes, essential amino acid, functional properties, proximate composition, antinutritional factors. &nbsp

The effects of seed ingestion by livestock, dung fertilization, trampling, grass competition and fire on seedling establishment of two woody plant species.

The increasing rate of woody plant encroachment in grasslands or savannas remains a challenge to livestock farmers. The causes and control measures of woody plant encroachment are of common interest, especially where it negatively affects the objectives of an agricultural enterprise. The objectives of this study were to determine the effects of gut passage (goats, cattle), dung (nutrients), fire, grass competition and trampling on establishment of A. nilotica and D. cinerea seedlings. Germination trials were subjected to the following treatments: 1) seed passage through the gut of cattle and goats and unpassed/ untreated seeds (i.e. not ingested), 2) dung and control (no dung), 3) grass and control (mowed grass), 4) fire and control (no fire), 5) trampling and control (no trampling). The interaction of animal species, grass and fire had an effect on seedling recruitment (P < 0.0052). Seeds retrieved from goats and planted with no grass and with fire (6.81% ± 0.33) had a significant effect on seedling recruitment than seeds retrieved from goats and planted with grass and no fire (2.98% ± 0.33). Significantly more D. cinerea and A. nilotica seeds germinated following seed ingestion by goats (3.59% ± 0.16) than cattle (1.93% ± 0.09) and control or untreated seeds (1.69% ± 0.11). Less dense grass cover, which resulted in reduced grass competition with tree seedlings for light, space and water, and improved seed scarification due to gut passage were vital for emergence and recruitment of Acacia seedlings. These results will contribute considerably to the understanding of the recruitment phase of woody plant encroachment.

The effects of passage through the gut of goats and cattle, and the application of dung as a fertiliser on seedling establishment of Dichrostachys cinerea and Acacia nilotica

Seed pods of Dichrostachys cinerea and Acacia nilotica have higher nutritive value than grasses and other browse plants during the dry season and form an important part of the diet of livestock. Seeds of Acacia may be destroyed during passage through the digestive tract of herbivores whereas seeds of other browse species can remain viable even after mechanical (chewing) and chemical (digestive) scarification. The seedling emergence, seedling establishment and recruitment of D. cinerea and A. nilotica seeds, dispersed by cattle and goats, were measured under natural conditions in the wet and dry seasons following sowing in the dry season. Seeds retrieved from goats and cattle, during the first 3 days and the last 4 days of the recovery period, and control seeds were subjected to the following planting methods: (1) seeds placed on top of the soil with no dung, (2) seeds buried to a depth of 2 cm in the soil with no dung, and (3) seeds buried to a depth of 2 cm in the soil with dung, in the wet and dry seasons. Significantly more A. nilotica and D. cinerea seeds were retrieved from cattle (40.0 ± 3.6% and 25.7 ± 3.9%, respectively), than goats (11.7 ± 3.1% and 13.2 ± 3.8%, respectively). There were significant interactions among animal species, seed-recovery day, planting and season for percentage seedling recruitment. Seedlings from seeds retrieved from goats (12.0 ± 0.06%) had a significantly higher recruitment rate than from seeds retrieved from cattle (7.6 ± 0.05%) and control seeds (i.e. no passage through the gut) (4.1 ± 0.02%). Seedling recruitment rate was higher from seeds recovered from animals in the last 4 days of the recovery period and from D. cinerea than A. nilotica. The planting method of seeds buried to a depth of 2 cm in the soil with no dung had the highest seedling recruitment rate. We conclude that both goats and cattle may facilitate woody plant encroachment by enhancing seedling emergence.

Diet Quality Modifies Germination of Dichrostachys cinerea and Acacia nilotica Seeds Fed to Ruminants

The pods of many woody plants form an important part of the diet of livestock during the dry season due to their high nutritive value. However, the dispersal of seeds that remain intact and can potentially germinate after excretion is of particular concern when animals consume seeds of encroaching or invasive woody plants. The objectives of this study were to determine the effects of animal species in two experiments (experiment 1: goats, sheep; experiment 2: goats, cattle), diet quality (Medicago sativa hay, Digitaria eriantha hay) and seed characteristics (size, hardness) on the effectiveness of animal seed dispersal and germination of Dichrostachys cinerea and Acacia nilotica seeds. Owing to a limitation on the availability of seeds, the two experiments were done separately at different times. Each animal in both experiments received 1 000 A. nilotica seeds and 1 000 D. cinerea seeds mixed with either a low-quality diet (D. eriantha hay) or a high-quality diet (M. sativa hay). In experiment 1, we found a significant interaction effect of animal species (goats, sheep), diet (high-quality hay, low-quality hay), and seed species (A. nilotica seeds, D. cinerea seeds) on germination (P < 0.0001). There was also a higher seed recovery (P < 0.009) when animals were offered high-quality hay (47.4% ± 4.65) compared to low-quality hay (30.2% ± 3.24). In experiment 2, animal species affected seed recovery (P < 0.0325; goats 32.0% ± 6.44; cattle 50.3% ± 4.27) and germination percentage (P < 0.055; goats 14.1% ± 1.48; cattle 9.3% ± 0.94). The diet quality fed to the animals may affect dispersal and germination. However, animal species and seed characteristics also had important effects on germination of D. cinerea and A. nilotica seeds. Thus, all three of these factors play a major role in dissemination of viable seeds.

Annona squamosa and Catunaregam nilotica Seeds, the Effect of the Extraction Method on the Oil Composition

AbstractAnnona squamosa and Catunaregam nilotica seeds and oils were characterized for their approximate analysis and physico‐chemical properties. The oil and protein contents were 26.8, 17.5 and 40.0, 22.2%, in A. squamosa and C. nilotica seeds, respectively. The oils were extracted using cold extraction (CE) and Soxhlet extraction (SE) methods. Fatty acids and tocopherols were determined by GC–MS and HPLC, respectively. Generally the physico‐chemical properties and fatty acids were not significantly (P ≤ 0.05) affected by the extraction methods. The major fatty acids of A. squamosa oil extracted by CE and SE were oleic 49.2 and 50.5%, linoleic 22.3 and 22.7%, palmitic 15.6 and 15.2%, and stearic 10.6 and 9.3%, respectively. While the major fatty acids in C. nilotica oil extracted by CE and SE were oleic 10.5, and 10.4%, linoleic 63.1 and 63.4%, palmitic 9.7 and 9.8% and stearic 5.1 and 5.4%, respectively. The tocopherol content of CE and SE extracted oils from A. squamosa amounted to 16.6 and 15.5 and from C. nilotica amounted to 110.5 and 107.7 mg/100 g oil, respectively, with delta‐tocopherol as the predominant tocopherol in A. squamosa oil, and beta‐tocopherol in C. nilotica oil. The total amount of amino acids was found to be 7.266 and 14.202 g/100 g protein, in seeds of A. squamosa and C. nilotica, respectively.

Effect of biofertilizers on quality seedling production of Acacia nilotica

Nursery experiments were conducted to select the suitable biofertilizers and their combination to improve the quality of Acacia nilotica seedlings. Nilotica seeds were germinated in poly pot with a potting mixture of unsterilized sand. Seedlings of 5 cm length were transplanted to polyethylene bag (13 x 25 cm). The biofertilizers such as Rhizobium, Arbuscular Mycorrhizal (AM) fungal species Glomus fasciculatum and Azospirillum, were inoculated individually and in combinations. Root, shoot length and collar diameter were recorded six months after inoculation the root and shoot weight, number of nodules and nodular weight was estimated. Results show that the total length of seedlings and biomass were significantly increased in all the treatments when compared to control. Among the treatments maximum growth and biomass were recorded in Rhizobium + AM + Azospirillum combination and it was recorded 156.8% more than that of control. Among the individual inoculations, Rhizobium treatment was better than other individual inoculation. Within double inoculations, Rhizobium + AM combination was found to be superior to others. In general, Azospirillum and its combinations with other biofertilizers had more root length and root biomass than other treatments.

Effects of seed drying, storage and pretreatments on the germination and growth of Acacia auriculiformis and Acacia nilotica seedlings

Acacia auriculiformis and Acacia nilotica one-day sun dried seeds with moisture content of 11.02% and 8.34% were stored in gunny bags and air tight plastic containers. The results indicated that seeds with good germination percentage (&gt;60%) can be stored for 6-8 months in gunny bags and 10-12 months in air tight plastic containers at room temperature for Acacia auriculiformis and Acacia nilotica, respectively. Acacia auriculiformis and Acacia nilotica seeds were nicked, immersed in hot water and soaked in sulphuric acid to improve germination and to determine their effects on germination and vigour of subsequent seedling growth. Nicking showed highest germination percentage and germination energy for both species, but most of the resultant seedlings were in the low vigour class. For Acacia auriculiformis soaking of seeds in acid for 30 minutes and immersing seeds in hot water for 5 minutes and 1 minute produced high germination and germination energy and the most of the seedlings were in high vigour category. For Acacia nilotica hot water treatment for 1 minute and H2SO4 for 30 minutes produced a high germination percentage and the seedlings represented high growth vigour.

Paddock‐scale patterns of seed production and dispersal in the invasive shrub Acacia nilotica (Mimosaceae) in northern Australian rangelands

AbstractPaddock‐scale Acacia nilotica L. Willd. ex Del. (prickly acacia) spatial distribution, seed production and dispersal patterns were investigated in the Astrebla (Mitchell) grasslands of northern Australia as a step toward predicting future patterns of invasion. A number of hypotheses were tested based on what we know of this species in both Australia and regions where it is native, for example South Africa. It was hypothesized that most A. nilotica seeds would be produced by trees in riparian habitats with access to permanent water. In addition, we predicted that seeds would be dispersed throughout the Astrebla grassland landscape by cattle, following observations that cattle readily ingest and pass seeds and that cattle have access to all areas within paddock boundary fences. Tree density, seed production and seed dispersal by cattle were measured along a series of transects from permanent watering points to paddock boundary fences. Trees associated with permanent watering points produced more seeds per unit area and occurred at higher density than their non‐riparian counterparts. The importance of riparian trees decreased in years with high rainfall and in paddocks with only small areas of riparian habitat. Cattle spread dung and seeds throughout paddocks, with peaks of deposition adjacent to permanent watering points. These results suggest that invasion patterns are likely to be uneven across the landscape and may be reactive to climate. High seedling recruitment and possible thicket formation is expected adjacent to permanent watering points and wherever cattle congregate. Patterns of recruitment in non‐riparian areas are likely to be relatively sparse. The importance of post‐dispersal factors in determining recruitment patterns is discussed.

Spatial distribution of soil seed banks of three African savanna woody species at two contrasting sites

In southern African savannas, bush encroachment is a major problem for range managers. However, little is understood of the actual regeneration processes leading to it, and in particular the role of soil seed banks. The horizontal (between microsites) and vertical (with depth in litter and soil) distribution of soil seed banks of the microphyllous woody species, Acacia tortilis, A. nilotica and Dichrostachys cinerea (all legumes of the Mimosoideae), were quantified in an area with low intensity grazing (reserve), and a bordering cattle farm with high intensity grazing (farm). Species differed in seed bank densities between microsites and sites. Seed densities for all species were highest below parent tree canopies and decreased with distance beyond the canopy, and with soil depth. D. cinerea had the smallest seed bank associated with parent trees, particularly on the farm (8 vs. 1643 seeds/tree on the reserve), A. tortilis had the largest (6357, 31910), with A. nilotica intermediate (1789, 1906). The proportion of current (recently fallen) versus old (≥1 year old) seeds differed between species and sites. These species form at least short-term persistent seed banks with the old seeds largely representing the persistent seed bank. Seed densities in the open (inter-canopy) and those dispersed under either of the other two (non-parental) study species were much lower than those associated with parent trees. The latter were mostly found under the acacias (single-stemmed) rather than D. cinerea (multistemmed). Total seed store per parent plant increased with plant size (best fits were mostly power curves of canopy area). A large proportion of intact seeds were viable, namely 81–84% for A. tortilis, 68–77% for A. nilotica and 63–78% for D. cinerea, with no differences between sites. Viability tended to increase with depth of burial, except for A. nilotica seeds at the 3–5 cm depths on the farm. At the landscape scale there were 1.5 million and 140 000 A. tortilis seeds/ha on the reserve and farm respectively, with corresponding values of 2000 and 31 000 for D. cinerea, and 23 000 and 86 000 for A. nilotica.

Effect of diet and seed pretreatment on the biology of Bruchidius uberatus (Coleoptera, Bruchidae)

Diet significantly (P &lt; 0.0001) affected fecundity of Bruchidius uberatus Fahraeus. Provision of 1% sugar solution increased fecundity from 15 eggs/female to 47. Furthermore, sugar solution prolonged significantly the oviposition period of B. uberatus from one week to two weeks. Diet also significantly (P &lt; 0.0001) increased adult longevity. Mean adult longevity recorded was 3, 7 and 13 days in control, water and sugar treatments, respectively. Seed pretreatment had a highly significant impact on the various developmental stages of B. uberatus. Maximum egg hatchability occurred in non-husked Acacia nilotica (L.) Willd. ex Del. seeds (83%), moderate in de-husked seeds (74%) and least in seeds presoaked in concentrated sulphuric acid (42%). The frequency of larvae that developed successfully into pupae was greatest in non-husked seeds (72%), nevertheless in de-husked and acid pretreated seeds, absolutely no larvae developed into pupae and hence the adult stage was not reached in these two treatments. Thus, de-husking and acid pretreatment of A. nilotica seeds is highly recommended.

The pharmacological effects of an aqueous extract from Acacia nilotica seeds

The pharmacological effects of an aqueous extract from Acacia nilotica seeds

The pharmacological effects of an aqueous extract from Acacia nilotica seeds.

An aqueous extract of the seed of Acacia nilotica was investigated for its pharmacological profile. On the isolated guinea-pig ileum, the extract displayed sustained dose-related contractile activity. The contractions which were reduced by hexamethonium, promethazine or atropine were completely abolished by nifedipine. The intravenous (i.v.) administration of the extract (11, 22, 44, 55 microg/kg) to anaesthetized cats produced a dose-related significant elevation of blood pressure. The mechanisms of the spasmogenic and vasoconstrictor actions of the extract have not been determined, however, the results suggest the involvement of calcium.