Showing papers in "Journal of Food Agriculture & Environment in 2006"

Compositional evaluation of cowpea (Vigna unguiculata) and scarlet runner bean (Phaseolus coccineus) varieties grown in Nigeria

Abstract: Dehulled samples of two cowpea (Vigna unguiculata) and two scarlet runner bean (Phaseolus coccineus) varieties were studied for nutritional evaluation with respect to proximate, mineral and amino acid composition. The samples contained crude protein in the range of 75.3– 526.1 g kg –1 DM with cream coat scarlet runner beans having the highest and cream coat moderate cowpea the lowest value. The crude fat varied with values ranging from 21.3±0.0 g kg -1 in white coat small cowpea to 75.3±0.1 g kg -1 in white coat scarlet runner bean. Proximate composition ranges were: moisture content 4.0–18.0, crude fibre 24.0–440, ash 36.1– 46.1 and carbohydrate (by difference) 301.1–828.3 g kg -1 DM. The most abundant minerals were Ca (594.2–664.3 g kg -1 ), Mg (546.1–677.1 g kg -1 ) and K (357.5–404.8 g kg -1 ). Generally the two legume varieties were found to be good sources of essential minerals while Co, Pb, Cd and Cr were not detected. The levels of Na/K and Ca/P ratios were desirable compared with the recommended values. The amino acid analysis revealed that all the samples contained nutritionally useful quantities of most of the essential amino acids with total essential amino acid (TEAA) (with His) ranging from 43.79 to 48.31%. The first limiting amino acid was Lys (0.51–0.59) and calculated isoeletric point (ρl) ranged between 5.49 and 5.58.

Inhibition of lipid metabolic enzymes using Mangifera indica extracts

Abstract: This study assesses the effects of mango tree (Mangifera indica L.) extracts (stem bark – MSB and leaves – ML) on lipases (pancreatic lipase, lipoprotein lipase and hormone-sensitive lipase). The MSB and ML samples were extracted in 95% ethanol and the extracts assayed for the inhibition of pancreatic lipase (PL) and lipoprotein lipase (LPL) as well as for the inhibition of lipolysis of 3T3-L1 adipocytes. We have also examined the anti-obesity action of MSB and ML by testing whether the extracts prevented weight gain induced by feeding a high-fat diet to male Wistar rats for 12 weeks. Both MSB and ML inhibited PL and LPL, suggesting that they may affect both fat absorption and the uptake of fatty acids, if enough of the active components can be absorbed and entered into the circulation. The inhibition of stimulated lipolysis by MSB and ML suggested that the cells took up the active components of the extracts. In addition, MSB and ML increased fecal fat excretion and reduced serum glucose and insulin levels and down-regulated some obesity-related genes (LPL, hormone-sensitive lipase, fatty acid synthase, resistin) in liver and epididymal fat. The precise molecular mechanisms by which MSB and ML inhibit lipases and lipolysis still requires further investigation.However, the relative biochemical complexity of these extracts may produce a pleiotropic action on several lipid and carbohydrate metabolism targets simultaneously, making MSB and ML multifunctional botanical therapeutics useful in weight control. MSB and ML or some of their components may also provide effective biochemical tools for studying the complex relationships between energy balance, adiposity and endocrine function.

Bioremediation of a petroleum-hydrocarbon polluted agricultural soil at different levels of water application in Port Harcourt, Nigeria

Abstract: A combination of field cells was used in experiments involving biostimulation with agricultural fertilizers to evaluate the bioremediation of a crude oil polluted agricultural soil at different levels of soil water. Petroleum pollution of an agricultural soil was simulated on the field by pouring crude oil on the cells from perforated cans. Remediation options involving the introduction of mineral fertilizers and periodic application of different amounts of water to the contaminated soils were then utilized for treatment. Laboratory analysis of soil characteristics showed an increase in the total heterotrophic bacterial (THB) counts and a corresponding reduction in soil organic carbon and total hydrocarbon content (THC) at the end of the six-week remediation period. The percentage of THC reduction ranged from 44% to 90% in the five treatment cells. The control site, which received no treatment, revealed no significant hydrocarbon loss (3%) within the study period. The results of the total heterotrophic bacterial (THB) counts revealed that petroleum-degrading bacteria responded to variations in soil water level during their metabolic activity; this corroborated with the correlation analysis between percent of THC reduction and time across the treatment cells, which indicated significance at 5% probability level thus highlighting the position that different soil moisture levels induces marked differences in biodegradation rates as remediation period increases. This implies that the level of water in the soil is a major factor that affect biodegradation rate and hence attention has to be given to the control of the moisture level in the soil to optimum, in order to achieve an accelerated biological clean up of petroleum polluted agricultural soils in Port Harcourt, Nigeria.

Production, proximate and nutritional evaluation of sweet potato curd

Abstract: Sweetpotato (SP) is an important root crop grown all over the world and consumed either as a vegetable, boiled, baked or often fermented into food and beverages. A curd like product was prepared by fermenting boiled anthocyanin-rich SP puree and cow milk with curd (starter) culture (Lactobacillus bulgaricus, Streptococcus lactis, St. diaceticlactis, etc.). There were no variations in pH, titratable acidity and lactic acid in SP curd consisting different concentration of SP puree. However, curd with 8-12% SP puree was most preferred by a consumer’s panelist. The addition of SP puree (8-12%) made the curd quite firm and imparted flavour, body/texture, minerals, nutrients, antidiabetic substances, anthocyanin pigments (antioxidant), dietary fibres and starch (carbohydrate source). The lactic acid bacterial counts in the curd after 18 h fermentation having 8 and 12% sweetpotato were 5x10 7 and 7x10 7 (CFU ml -1 ), respectively.

Antioxidant capacity of dry vegetal extracts checked by voltammetric method

Abstract: In the present research some of the vegetal matrixes that are more common and more frequently described in the literature for their high antioxidant activity, such as green tea, black tea, rosemary and coffee, were selected and analysed to test the total antioxidant capacity of respective dry extracts. In addition to these products, which are well known and extensively investigated, it was deemed of interest to test acerola and acai, i.e. new food products from the Brazilian Amazon forest, which have only recently become the focus of interest for food and drug industries. Also analysed were two herb teas consisting of a mixture of natural antioxidants called Herb Tea and Quality Tea. Methanol, acetone and aqueous dry extracts were prepared from each of these vegetal matrixes, using for extraction solvents considered to be complementary in processes for the extraction of antioxidant substances present in the vegetal matrixes. For the three extracts obtained from each matrix the antioxidant capacity was determined using a new electrochemical method based on the measurement of the anodic area of a cyclic voltammogram.

Phenotypic divergence in the meta-population of the Hourani durum wheat landrace

Abstract: The Hourani durum wheat landrace was cultivated for millennia in the Houran plateau of Northern Jordan and Southern Syria. Recently, however, it’s meta-population became highly fragmented due to the introduction of high yielding varieties, new crop rotations and new cropping systems. Its genetic divergence was assessed in 289 populations collected from five villages in each of two eco-geographical regions in each country. Total variation in 15 plant, spike and seed attributes was apportioned among populations (13.5%), among farms (18.3%), among villages (16.5%), among eco-geographical regions (46%) and among countries (5.7%). Percent correct classification of germplasm by village based on discriminant analyses was 71 and 65% in semiarid and arid villages, respectively. This confirms the existence of a highly divergent germplasm in this landrace, with geographical distances among villages being correlated with squared Mahalanobis distances based on all 15 plant, spike and seed attributes (r=0.59; p=0.05).

Productivity and technical efficiency of oil palm production in Nigeria

Abstract: Efficiency is an important factor of productivity in a growing economy like Nigeria where there are dwindling resources for adoption of improved technologies for increased production. The objective of this paper was to investigate the productivity and technical efficiency of oil palm production among oil palm farmers in Nigeria using the stochastic frontier production function analysis. Primary data were collected using a set of validated structured questionnaire from 241 oil palm farmers who were selected through multistage random sampling from six local government areas of Edo and Ondo States, Nigeria. Given the specification of the stochastic frontier production function, the null hypothesis that the oil palm farmers were fully technically efficient is rejected since there were presence of inefficiency effects in the model. Results showed that predicted technical efficiencies varied widely across the farms, ranging between 0.463 and 0.999. The study further showed that oil palm production in the study area was generally in the rational stage of production as portrayed by the returns to scale of (RTS) 0.771.

The effect of NaCl priming on cucumber seedling growth under salinity stress

Abstract: Seeds of two Iranian cucumber cultivars, Basmenj and Varamin, were primed (P) with 15 dS m -1 NaCl solution for 36 h at 20°C. Non-primed (NP) and primed (P) seeds were sown in trays containing perlite. The trays were placed in an unheated greenhouse and irrigated with different levels of NaCl solution (0.3 (control), 2.5, 5, 9 and 13 dS m -1 ) for a period of 4 weeks. Total emergence, emergence rate, radicle length and dry weight of seedlings derived from P seeds were higher than NP seeds. NaCl priming increased uptake of K and Ca and accumulation of proline in cucumber seedlings. These results indicated that NaCl priming increased salt tolerance of cucumber seedlings by promoting K and Ca accumulation in addition to inducing osmoregulation by accumulation of proline.

Rumen degradation and in vitro gas production parameters in some browse forages, grasses and maize stover from Kenya.

Abstract: Forages from five browse species Bauhinia alba, Carisa edulis, Lantana camara, Sesbania sesban and Tithonia diversifolia; two grass species Chloris gayana and Pennisetum purpureum and crop residue maize (Zea mays) stover were analysed for chemical composition including phenolics and rumen degradation characteristics. The rumen fermentation characteristics with and without polyethylene glycol (PEG) were studied in vitro by gas production. The crude protein content was more than 200 g/kg dry matter (DM) in S. sesban and T. diversifolia while was lowest in C. gayana hay and maize stover. The organic matter (OM) (g/kg DM) was high in C. edulis (945.3) and low in P. purpureum (837.3) while C. gayana hay and maize stover contained the highest neutral detergent fibre (NDF). Total extractable phenolics (TEPH) and total extractable tannins (TET) tended to be high in B. alba and C. edulis. The DM disappearance after 24 h of rumen incubation ranged from 44.1 in C. gayana hay to 82.4% in T. diversifolia. The effective degradability (ED) was high in the browse forages than the grasses and maize stover. The gas produced after 96 h of incubation ranged from 23.9 in B. alba to 52.8 ml/200 mg DM in maize stover. The grasses and maize stover produced more gas than the browse forages at all incubation h after 24 h. Use of PEG indicated that tannins had inhibitory effect on rumen microbial fermentation and that this depends on the amount and activity of the tannins present. The estimated in vitro OM digestibility and metabolizable energy also increased numerically with PEG addition. The results of this study indicates that such browse forages have the potential to be used as feed supplements for ruminants especially during the dry season when feeds such as hay and crop residues are the only feed resources available to the farmers.

Compatibility of plant oils and additives with Paecilomyces farinosus, a potential entomopathogenic fungus

Abstract: Addition of oils increases the infectivity of entomopathogens by enhancing conidial adhension, prolonged persistence and infectivity against the target pests. An in vitro study, by following the poison food technique was conducted to determine the compatibility of plant oils and adhesive stickers in enhancing the infectivity of Paecilomyces farinosus, a potential entomopathogenic fungi. The compatibility of seven plant oils viz; coconut, groundnut, gingili, sunflower, neem, pongamia and castor oil and two adhesive stickers (Laboline and Triton X 100) with P. farinosus was investigated by measuring the radial growth of fungus at 5 th , 10 th and 15 th day and the conidial spore yield of inoculation. The compatibility of the fungi to the oils and stickers studied varied. Among the oils and adhesives screened, groundnut, pongamia, gingili and castor oil and Triton X 100 were non-compatible with the fungus. Addition of sunflower, coconut and neem oil and Laboline enhanced the mycelia growth and sporulation of the fungus. Adding these oils and sticker with the fungi could increase their effectiveness as a bio-pesticide against the target pests.

Functional properties of extruded soybean with plantain flour blends

Abstract: The proximate composition and functional properties of extruded/fermented soybeans with plantain flour blends were determined. Plantain flours were prepared from mature unripe and ripe plantain (Musa aab) after oven drying at 80°C for 12 hours. Cleaned soybean seeds were manually dehulled after soaking in water at room temperature for 3 hours. The sample was then oven-dried and another batch was fermented. Dehulled soybean and fermented soybean were extruded and blended with each of the unripe and ripe plantain flours at ratios 0, 25, 50, 75 and 100. Proximate composition showed that fermented extruded soybean had the highest protein content (41.1%). The value recorded for non-fermented extruded soybean was 31.5% while the values for the formulated blends ranged from 7.0 to 29.8%. The lowest content (4.4%) was recorded for plantain flour. When compared with both fermented and non-fermented soybean samples, the protein content of the formulated blends increased as the percentage of protein inclusion increased. Extrusion cooking reduced the moisture content of the products hence prolonging the shelf-life. Water absorption capacity ranged from 120 to 270%. The highest value was recorded for fermented extruded soybean, the values for raw soybean and non-fermented extruded soybean were 220 and 250% respectively. Fermentation decreased oil absorption capacity and emulsion capacity of the formulated blends. Least gelation concentrations of fermented extruded, non-fermented extruded and raw soybean were 24, 22 and 18% respectively. Loose and packed bulk densities showed advantage of economy with packaging. These results indicate potential food uses of fermented and non-fermented extruded soybeans with plantain flour blend as breakfast food, soup bases and ingredient in formulated foods.

Sustainable agriculture for environment protection: cooperation between China and Italy.

Abstract: After a short introduction on the importance of the agro-food sector in the economies of most of present-day societies, the article focuses on the role of agriculture in protecting the environment and enhancing biodiversity. The importance of a shift toward agricultural systems, which are more complex in terms of biodiversity in emerging countries such as China, where most of the population (about 70%) lives in rural areas, in poor conditions and still relies on agriculture as the main source of income is discussed. In China the risk of shifting to more intensive and polluting agricultural production patterns to address the demand for food of the growing population and the need of higher incomes of rural communities is relatively high. With the present Chinese economic growth, urbanization and increased leisure time, tourism and recreation activities in rural areas are also increasing. Additionally, in the restructuring process of economy in rural areas, one of the most obvious effects is the necessity to create job opportunities alternative to agricultural sector. The role of sustainable agriculture for environment protection in a country such as China is highlighted. The attention paid to activities in the agro-environmental sector has been increasing over the years in this country due to the high social and economic priority attached by the Chinese authorities to the modernization of agriculture that must be pursued in a sustainable manner, addressing at once food security, environment protection, economic development and good management of natural resources. The experience gained in the framework of the Sino-Italian Cooperation Programme for Environment Protection jointly launched by the Italian Ministry for the Environment and Territory (IMET) and the State Environment Protection Administration of China (SEPA) in the year 2000, through the implementation of several cooperation projects in different rural areas of China is critically discussed. The approached adopted, avoiding pursuing short-term objectives, due to the pressure for profit, to ensure the replicability and long-term sustainability of transferred technologies are described. Important in all cooperation projects carried out have been training and information activities to enable the actual transfer into practice of target sustainable agricultural technologies and practices. All stakeholders have been involved in project preparation and implementation. Particularly, academic institutions, public research centers and private companies have been partnered with the aim of creating long lasting network of local and international researchers and experts supporting the development and the adaptation of sustainable farming systems as well as the design of new regulatory framework supporting the adoption of innovative technologies. District workshop and seminar have been organized in order to keep people involved in project activities continuously aware of all progress as well as to inform stakeholders on scientific, technical and economic feasibility of upcoming new techniques and systems. The synergic role provided by the different projects in promoting environment protection and sustainable agriculture at once, represents a strong effective effort toward the rural development of different regions.

Induction of callus and somatic embryogenesis from cotyledonary explants of Parkia timoriana (DC.) Merr., a multipurpose tree legume

Abstract: To explore the potential for in vitro rapid regeneration of Parkia timoriana, a multipurpose tree legume, cotyledon explants were cultured on MS and B 5 basal media supplemented with various concentrations of 2,4-D, NAA and BAP. Successful callus induction was observed in all the treatments. Maximum percentage of callus induction was obtained in the 2,4-D supplemented basal media. However, the overall response of MS medium was found to be superior to that of B 5 medium. Explants cultured on MS medium fortified with combinations of 2,4-D and BAP induced rapidly proliferating calli that turned more friable and nodular. These protuberances eventually developed into somatic embryos when transferred in basal MS suspension medium without growth regulators. The protocol described here is the first on P. timoriana and has the potential to produce plantlets through somatic embryogenesis and also offers a highly efficient method for mass clonal propagation and conservation for this multipurpose legume tree.

Antioxidant activity of tropical fruit jam and marmalade processed with different combinations of peel and flesh in Citrus fruit

Abstract: The antioxidant activities of marmalade with varying combinations of peel and flesh were investigated in three types of Citrus fruit: satsuma mandarin (Citrus unshiu Marc.), shiranui [(Citrus unshiu Marc × Citrus unshiu Osbeck) × Citrus reticulata Blanco] and navel orange (Citrus sinensis Osbeck). The antioxidant activity was estimated in three ways: according to the superoxide (O 2 )-radical scavenging activity, according to the 1-diphenyl-2-picrylhydrazyl (DPPH)-radical scavenging activity and by an assay of the hemolysis of red blood cells. Although the levels of O 2 and DPPH IC 50 in the peel were lower than those in the flesh, the levels of IC 50 for both O 2 and DPPH in the marmalade that was composed of only peel (P) were higher than those in the marmalade made with a combination (PFJ) of peel and flesh juice or a combination (PFB) of peel and flesh juice, and the water in which the peel had been boiled (BW). It is possible that the decrease of total ascorbic acid (AsA) and total phenolics in the peel that was boiled in water were caused by the higher IC 50 . In contrast, O 2 and DPPH IC 50 in the PFB and BW marmalade were low. The hemolysis of red blood cells was slowest in BW. These findings indicate that adding BW to marmalade increases the antioxidant activity in marmalade. The antioxidant activity in jam made from tropical fruits including papaya (Carica papaya L.), mango (Mangifera indica L.), guava (Psidium guajava L.) and star fruit (Averrhoa carambola L.) were also examined. O 2 and DPPH IC 50 were lowest in the guava jam. It is considered that the high AsA and total phenolic concentrations in guava jam are related to the strong antioxidant activity.

Peroxidase activity (POX) in some cucurbits under the stress of mercury and lead

Abstract: Peroxidase (POX) activity in Cucumis sativus L., Lagenaria siceraria (Mol.) Standl., Luffa cylindrica L. and Momordica charantia L. was studied under the stress of mercuric chloride and lead nitrate. High level of peroxidase activity was detected in all tissues when compared with the controls, roots having the highest activity. The high POX activity observed in tissues treated with both heavy metals (Hg and Pb) might indicate the initiation of disruption in biochemical processes. Generally it can be concluded that heavy metals cause severe stress to plants leading to highly effective defence reactions.

Determinants of households' participation in social forestry in arid zone of Northern Nigeria.

Abstract: Cross-section data were used to examine characteristics of social forestry activities from 145 farm families in selected arid zone States of Borno, Kano and Sokoto, Nigeria. Findings show that participation was significantly determined by selected socio-demographic factors such as age, farm size, income, education and tangible infrastructural asset. Results show in particular that farm size is not a limiting to social forestry participation. One explanation that could be offered for the significant positive farm size is that households with large farm size are more likely to be able to set aside portion of their marginal land to woodlots without jeopardising household food security on the remaining land. Finding further shows that older and more educated rural households with large farm size participated more in social forestry activities. Again, there was a clear division of labour along gender lines as men participated in core forestry activities requiring physical exertion such as tree planting, weeding, harvesting and protection while women engaged in priorities related to processing, sales and fuel wood collection. The study noted that there is still much to be done as participation is currently still low when viewed against the vast deteriorating environment in the arid zone. The study recommends that when designing forestry programme, considerations should be given to those significant variables; increase the access of the local communities to improved infrastructure and on upgrading the skills of rural households through forestry extension education.

Phosphorus fertilization effect on dry matter production and biomass partitioning in sweet potato (Ipomoea batatas) grown on an acidic loamy-sand Alfisol

Abstract: Augmentation of soil available phosphorus (P) is often essential to reverse the acid infertility conditions of most tropical soils, especially when arable crop growers prefer tubers or grains to excessive vine and leaf production. As part of the ultimate goal to recommend fertilizer use for crop production on a medium acid (pH 5.8) luvisol/alfisol (Typic Paleustalf), this study sought to evaluate the effect of P fertilization on the dry matter (DM) production and biomass partitioning at successive growth periods of sweet potato (Ipomoea batatas) grown on the benchmark soil type. The plants were treated to three levels (0, 30 and 60 kg/ha) of P using single super phosphate, SSP (9% P). The treatments were replicated three times to give a total of nine experimental field plots in randomised complete block design. The changes in DM contribution of the plant parts (vine, root, petiole, lamina and tuber) after 3, 5, 7, 9, 11 and 13 weeks of growth were evaluated. Lamina, tuber and vine contributed most of the crop’s dry biomass at each of the P application levels and sampling periods while the seed stock contributed the least. The highest P contents in the lamina were recorded at the 5 th , 9 th and 7 th weeks after planting (WAP) for the P 0, 30 and 60 kg/ha treatments, respectively while DM production was at its respective peaks during the last sampling period (13 WAP). Maximum production of tuber and lamina was at P 30 and 60 kg/ha, respectively. The short- and long-term responses to SSP (compared with some other fertilizer materials) by selected cultivars of the crop need to be ascertained in future studies.

Comparative assessment of yield potentials of improved cowpea breeding lines using performance index and ranking methods

Abstract: Identification of the best variety from a variety trial is often done using the least significant difference (LSD), Duncan’s multiple range test (DMRT) and stability analysis methods. However, these methods are unable to discriminate among a smaller group of varieties which are not statistically significantly different from each other. Therefore, there is a need for another method which can further discriminate among these small groups of varieties. This study was undertaken to assess the efficacy of the performance index (PI) and rank total (RT) methods in identifying the best variety from a variety trial. Eighteen cowpea breeding lines including a local check were grown for two years in three environments representing the major cowpea growing zone of West Africa to assess their grain yield potential. The yield data were analyzed and variety means were compared using different methods. The PI revealed that IT98K-398-14 was the best with a PI index of 88% compared to 59% for IT98K412-13 and IT98K-506-1 with 35%, and RT method showed IT98K-412-13 with RT of 34, IT98K-398-14 with RT of 35 and IT98K-506-1 with RT 42 as the most promising cowpea varieties while the stability analysis indicated IT98K-506-1 with a b value of 1.03 as the most stable variety in the test environments with a mean yield of 1491 kg ha -1 which is above overall mean yield of 1340 kg ha -1 . The PI is a simple and easy approach to classify varieties especially when the number of varieties and test environments is large. The RT method is also an alternative approach devoid of much calculation and will therefore be a valuable tool for plant breeders especially when quick decisions are to be made on the selections of varieties. All three methods identified the same three varieties as the best varieties.

Electroosmosis dewatering of tomato paste: Experimental data and neural network modeling

Abstract: An electroosmotic device was designed to remove water from tomato paste suspensions. The suspension was held in vertical column of 9.1 cm height and between two stainless steel electrodes, an upper serves as anode while the lower serves as a cathode. Direct current electroosmosis dewatering was achieved by the application of an electrical field which allows water to pass through the filter paper held in the lower section. The effects of voltage, current and initial solid concentration on the amount of water removal were examined. The energy of dewatering can be calculated from the measured experimental data. The experimental data were represented by neural network modeling scheme which describes the data accurately and adequately.

Characterization of pepino accessions and hybrids resistant to tomato mosaic virus (ToMV)

Abstract: Pepino (Solanum muricatum Aiton) is a vegetable crop domesticated in the Andean region with great possibilities for being introduced in Mediterranean climate areas as a new crop. However, tomato mosaic virus (ToMV) can restrict pepino expansion, due to delay in fruit ripening and loss of quality of fruits caused by the virus, which make the fruits non-marketable. Three accessions of pepino previously identified as resistant through hypersensitive reaction (HR) against mechanical inoculation were characterized for their resistance behaviour in three different ranges of temperature (high: 28oC< t <36oC; medium: 25oC/18oC (day/night); low 12oC< t <20oC). The movement of the virus within the plant at short distance (within the leave) and long distance (through all the plant), as well as the reaction to different types and dilutions of inocula were studied. These accessions give resistant reaction at low and medium temperatures, while at high temperature they behave as susceptible. Hybrids between resistant accessions and the susceptible accession ‘Sweet Round’ showed different segregation patterns depending on the resistant parent used. Due to the vegetative propagation system used with pepino, successful selection among resistant hybrids could quickly yield resistant commercial varieties. These varieties combined with suitable prevention measures will avoid damage to the pepino crop caused by ToMV.

Multivariate Phenotypic Structures in the Batini barley landrace from Oman

Abstract: We identified 14 phenological classes in three (grain, forage and dual-purpose) end-use types and formulated discriminant functions to help select elite germplasm for breeding purposes. Biological yield, pre- and post-anthesis thermal time, grain yield, plant height and tillers per plant, in decreasing order, were most influential in discriminating among phenological classes. Extensive divergence in the phenotypic covariance matrices among phenological classes suggests that directional selection, especially in the phenological traits, resulted in large, idiosyncratic changes in the principal components’ structure, and that some of the changes are attributed to shifts in the mean phenotype. Knowledge of genetic co-variation of these traits will be useful for plant breeders by targeting traits that have a disproportionately large influence on differences in the mean covariance.

Reaction of cotton and soybean cultivars to populations of Meloidogyne javanica and M. incognita in Zimbabwe

Abstract: The response of common cotton (Gossypium hirsutum L.) and soybean [Glycine max L. (Merr.)] cultivars in Zimbabwe to infestation by Meloidogyne javanica (Treub) Chitwood and Meloidogyne incognita (Kofoid & White) Chitwwod races 1 and 3 was evaluated. This was done under greenhouse conditions in two separate experiments at Kutsaga Research Station, Zimbabwe, in a program aimed at identifying alternative rotation crops for root-knot nematode management in tobacco (Nicotiana tabacum L.). Seedlings of each cultivar were raised in sterilised soil in 15 cm diameter pots. The inoculum which was applied three weeks after sowing was a mixture of eggs and second stage juveniles (J2s). The dosage was 4000 mixed eggs and J2s per plant for the soybean trial while it was 5000 for cotton. Nine weeks after infestation, root gall indices, numbers of nematode egg masses and eggs per root system were recorded. The numbers of J2s per pot were also recorded. Reproduction factor (RF) was computed as final population (eggs + J2s) ÷ initial population inoculated. All the cotton cultivars were susceptible (RF>1 and abundant galling) to M. incognita Race 3 while they were all resistant (RF<1) to M. javanica. The cultivars, TE-94-4, FQ 92-19, CY889, AG4869 and DF885 were resistant to M. incognita Race 1. The other three cultivars which were susceptible to M. incognita Race 1 did not show any damage symptoms suggesting that assessing for resistance using this criterion alone may be inadequate. The soybean cultivars were all susceptible to the three species except SNK60 which was resistant to M. incognita race 1 (RF=0). The cultivar, however, produced galls further indicating the inadequacy of using damage functions of Meloidogyne species for host status evaluation

Insulin resistance, diet and cardiovascular disease: A review

Abstract: Obesity and cardiovascular disease (CVD) are two of the leading causes of morbidity and mortality in developed countries. Direct influences of diet on obesity are obvious, however equally strong is the evidence that CVD is caused by and preventable by diet. A common link between these two conditions is insulin resistance (IR), characterised by elevated insulin levels due to an insensitivity to insulin’s action postprandally. Recent research has highlighted the strong connection between IR and incidence and severity of CVD. IR is associated with the generation of very small dense low density lipoprotein (LDL) which confers a high risk for cardiovascular disease, more so than any previously identified risk factor for CVD. Given the clear correlation with IR, dietary approaches may be considered to be highly effective as a treatment strategy or preventative measure. This review concentrates on this newly discovered link between IR and CVD, and presents a balanced view of dietary measures which could contribute to corrections in insulin imbalances, responsiveness to insulin, and therefore reduce CVD incidence and obesity.

Lewis acid-base concept - a unifying principle applicable to soil system, geochemistry and biology

Abstract: The concept of hard and soft Lewis acids and bases was reviewed as a unifying principle in the chemistry of soil system, in the geological distribution of elements and in living systems. The common aquatic character of natural environments with the important role of hard-hard interactions and the factors determining the bond strength were discussed. Further evaluations included the complexation tendency of hard ions in water solution which is parallel with the standard entropy of ions. In the soil system, these principles manifest as increased sorption ability of oxyacid ligands with increasing pKa of the acid, while the complexation of hydrated metal cations is enhanced with decreasing pK of hydrolysis. From mineralogical and metallurgical points of view the softness is expressed as poor hydration of inert noble metals. In biological systems, coordination environments for metals range from very hard oxygen donors to very soft sulphur donors.

Effects of weaning programs on serum metabolites and hepatic IGF-1 mRNA of first-calf heifers or mature cows

Abstract: Effects of early weaning calves on serum metabolites and hepatic insulin-like growth factor-1 messenger RNA (IGF-1 mRNA) of first-calf heifers or mature cows was investigated. Treatments were arranged in a 2 x 2 factorial and included 14 crossbred first-calf heifers and 14 crossbred mature cows assigned randomly to one of two treatment regimens: early-weaned (EW, calves weaned at an average age of 114 d) or normal-weaned (NW, calves weaned at an average age of 197 d). Blood samples were collected from dams on d 114, 141, 197 and 205 postpartum via coccygeal venipuncture. Heifers with calves EW experienced a greater increase (parity x weaning; P = 0.02) in BW over heifers with calves NW, but no change in BW due to weaning was observed for mature cows (P>0.71). Early weaning (vs. NW) increased (P 0.16) observed for serum IGF-1, serum non-esterified fatty acids (NEFA), or serum urea nitrogen (SUN). A parity x d interaction (P<0.05) for hepatic IGF-1 mRNA, serum IGF-1 and SUN, and a trend for parity x d for NEFA (P<0.10) were observed, but no differences were detected between first-calf heifers and mature cows within sampling d. Early weaning tended to decrease (P = 0.06) SUN compared with NW status. These results suggest that EW can increase BW and BC in first-calf heifers, and decrease SUN in both first-calf heifers and mature cows. However, no other differences in performance or serum chemistry were detected between first-calf heifers and mature cows with either weaning regimen applied, in open rangeland conditions of the arid southwest United States during drought.