Effects of inbreeding on nodal root system morphology and architecture of white clover (<Emphasis Type="Italic">Trifolium repens</Emphasis> L.)

Plants of white clover (Trifolium repens L.) cultivar Crau, a self-fertile Crau genotype, and nine generations of inbred progeny were raised in sand culture in a glasshouse experiment. Digital images of the root systems were made and root morphological characteristics were determined on all the plants. Root architectural parameters were measured on the Crau parent and the S₁, S₄, S₆, and S₉ inbred lines. The clover roots became shorter and thicker with inbreeding but the number of root tips per plant was unchanged. Root architecture (branching pattern) was largely unaffected by inbreeding. It is concluded that inbreeding white clover will lead to shorter, thicker roots, and reduced nutrient uptake efficiency compared with the parent clover. The degree to which these deleterious traits are overcome during the development of F₁ hybrids needs to be determined.     

Effects of Deficit Drip Irrigation Ratios on Cotton (Gossypium hirsutum L.) Yield and Fibre Quality

Increasing irrigation costs and declining water availability compel producers to adapt irrigation strategies for maximum crop yield and water use efficiency. A field trial was conducted to observe the effects of various drip irrigation ratios (IR-0, IR-25, IR-50, IR-75 and IR-100) on water use efficiency (WUE), the irrigation water use efficiency (IWUE), lint yield, yield components and fibre quality at two upland cotton varieties during 2004 and 2005. WUE was found to increase from 0.62 to 0.71 kg m⁻³ as the irrigation water applied was reduced from 100 % to 75 % of soil water depletion. Deficit irrigation of cotton with drip irrigation at 75 % treatment level (IR-75) did not decrease seed cotton yield and yield components during 2 years, with the exception of the number of bolls in 2005. Among fibre quality parameters, no significant differences in fibre length, fineness, uniformity index and elongation were detected between the 100 % and 75 % irrigation levels in 2005. The results revealed that irrigation of cotton with a drip irrigation method at 75 % level had significant benefits in terms of saved irrigation water without reducing yield, and high WUE indicated a definitive advantage of employing deficit irrigation under limited water supply conditions.     

The Optimization for Crop Planning and Some Advances for Water-Saving Crop Planning in the Semiarid Loess Plateau of China

The establishment of water-saving crop planning is an inevitable choice of the water-saving agriculture for the water-deficiency region in the arid and semiarid Loess Plateau of China and the world. The water-saving crop planning refers to the planting structure that centres the adjustment of the crop's adaptation to water, the optimization of temporal and spatial layout for crops, the local natural resources, marketing resources, human resources and financial input to enable region or basin with limited water resources to achieve the maximum economic, social and ecological benefits of planting industry under certain technology and economy. After the analysis on the research progress of optimization theory, optimization goals, optimization methods of water-saving cultivation structure and macro-control measures, it is pointed out that the main deficiencies of the current research of water-saving cultivation pattern optimization are lacking of a strong theoretical basis, and the immaturity of optimization technologies. The future crucial research direction will focus on five aspects such as the special optimization theory system, the division methods by studying the watershed unit and using 3S technology, optimization model based on multi-objective evolutionary algorithm, evaluation of rationality and macro-control measures on the basis of the public participation.     

Polyphenolic content in five tuscany cultivars of Olea europaea L.

In this study polyphenolic compounds extracted from olive fruits of five registered cultivars were analyzed. A solid-liquid extraction (LSE) procedure with Extrelut cartridge (diatomaceous earth) using different eluents was developed to obtain polyphenolic compounds. HPLC-DAD and HPLC-MS methods were applied for the quali-quantitative analysis of each fraction obtained from LSE. The results of this work show that the LSE procedure with diatomaceous earth cartridge supplies a rapid and reproducible fractioning method able to obtain a quantitative recovery of all compounds and to collect fractions directly analyzed by HPLC. A comparison among different cultivars shows significant quantitative differences in some polyphenols, such as verbascoside, anthocyanic compounds, and oleuropein derivatives.     

Capillary gas chromatographic detection of invert sugar in heated, adulterated, and adulterated and heated apple juice concentrates employing the equilibrium method.

The equilibrium method is introduced for the detection of invert sugar addition to apple juice. The method consists of a pre-equilibration of the sample with dry pyridine at 50 degrees C for 20 min followed by the addition of trimethylsilylimidazole and heating at 75 degrees C for 40 min. The resulting derivatized carbohydrates are then analyzed by capillary gas chromatography. This method was successfully used by independent laboratories to distinguish heated pure, intentionally adulterated (with invert sugar), and intentionally adulterated and then heated apple juice concentrates. The equilibrium method was shown to give significantly lower coefficients of variation for this sample set when compared to the original capillary gas chromatographic method. In addition, these results indicate that it may also be an effective method for the detection of medium invert sugar, depending on the level of the fingerprint oligosaccharides in this sweetener.     

Ion chromatographic determination of chloride in mustard sauces.

A new, simple, precise, and rapid ion chromatography (IC) method has been developed to determine chloride in mustard sauces using a mixture of phthalic acid, acetone, and water adjusted to pH 5.0 as eluent. Conductometric detection was carried out. The retention time for chloride was 1.5 min. Linearity was obtained up to a concentration level of 100 mg/L NaCl. The method was statistically evaluated for accuracy and precision after being used to assay the chloride from mustard sauces. Within the same samples, the chloride levels obtained by IC were compared with the sodium concentrations quantified by atomic absorption spectrophotometry.     

Flavonoid constituents of Chorizanthe diffusa with potential cancer chemopreventive activity

An ethyl acetate-soluble extract of Chorizanthe diffusa was found to exhibit significant antioxidant activity, as judged by scavenging stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and inhibition of 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced free radical formation with cultured HL-60 cells. Bioassay-directed fractionation of this extract using the DPPH antioxidant assay as a monitor led to the isolation of five structurally related flavonoids (1-5), including the novel compound 5,8,3',4',5'-pentahydroxy-3, 7-dimethoxyflavone (1). Isolates 1-5 demonstrated varying degrees of antioxidant or antimutagenic activity. Two of the compounds, 5,7,3', 4'-tetrahydroxy-3-methoxyflavone (2) and quercetin (4), were subsequently found to inhibit carcinogen-induced preneoplastic lesions in a mouse mammary organ culture model. Inhibitory activity of this type is known to correlate with cancer chemopreventive effects in full-term models of tumorigenesis.     

Ionic-strength and pH effects on the sorption of cadmium and the surface charge of soils

Two Oxisols (Mena and Malanda), a Xeralf and a Xerert from Australia and an Andept (Patua) and a Fragiaqualf (Tokomaru) from New Zealand were used to examine the effect of pH and ionic strength on the surface charge of soil and sorption of cadmium. Adsorption of Cd was measured using water, 0.01 mol dmp^?3 Ca(NO₃)₂, and various concentrations of NaNO₃ (0.01–1.5 mol dm^?3) as background solutions at a range of pH values (3–8). In all soils, the net surface charge decreased with an increase in pH. The pH at which the net surface charge was zero (point of net zero charge, PZC) differed between the soils. The PZC was higher for soils dominated by variable-charge components (Oxisols and Andept) than soils dominated by permanent charge (Xeralf, Xerert and Fragiaqualf). For all soils, the adsorption of Cd increased with an increase in pH and most of the variation in adsorption with pH was explained by the variation in negative surface charge. The effect of ionic strength on Cd adsorption varied between the soils and with the pH. In Oxisols, which are dominated by variable-charge components, there was a characteristic pH below which increasing ionic strength of NaNO₃ increased Cd adsorption and above which the reverse occurred. In all the soils in the normal pH range (i.e. pH>PZC), the adsorption of Cd always decreased with an increase in ionic strength irrespective of pH. If increasing ionic strength decreases cation adsorption, then the potential in the plane of adsorption is negative. Also, if increasing ionic strength increases adsorption below the PZC, then the potential in the plane of adsorption must be positive. These observations suggest that, depending upon the pH and PZC, Cd is adsorbed when potential in the plane of adsorption is either positive or negative providing evidence for both specific and non-specific adsorption of Cd. Adsorption of Cd was approximately doubled when Na rather than Ca was used as the index cation.     

Determination of insoluble, soluble, and total dietary fiber in foods and food products: interlaboratory study

A collaborative study was conducted to determine the insoluble dietary fiber (IDF), soluble dietary fiber (SDF), and total dietary fiber (TDF) content of food and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that developed for TDF only, which was adopted official final action by AOAC, except for changing the concentration of buffer and base and substituting hydrochloric acid for phosphoric acid. These changes were made to improve the robustness of the method. Duplicate blind samples of soy isolate, white wheat flour, rye bread, potatoes, rice, corn bran, oats, Fabulous Fiber, wheat bran, and a high fiber cereal were analyzed by 13 collaborators. Dietary fiber values (IDF, SDF, and TDF) were calculated as the weight of residue minus the weight of protein and ash. The coefficients of variation (CVs) of both the independent TDF determination and the sum of IDF and SDF were better than 15 and 18%, respectively, with the exception of rice and soy isolate. These 2 foods, however, contained only about 1% TDF. The CVs of the IDF were equally good, except for Fabulous Fiber, for which filtration problems occurred. The CVs for the SDF were somewhat high, but these products had very low SDF content. There was excellent agreement between the TDF determined independently and the TDF determined by summing the IDF and SDF. The method for separate determination of IDF and SDF requires further study. The modifications (changes in concentration of buffer and base and the use of hydrochloric acid instead of phosphoric acid) to the official final action method for TDF have been adopted.     

Effect of successive cuttings on uptake and partitioning of 15N among plant parts of Leucaena leucocephala

Summary We studied the effect of three successive cuttings on N uptake and fixation and N distribution in Leucaena leucocephala. Two isolines, uninoculated or inoculated with three different Rhizobium strains, were grown for 36 weeks and cut every 12 weeks. The soil was labelled with 50 ppm KNO₃ enriched with 10 atom % ¹⁵N excess soon after the first cutting. Except for the atom % ¹⁵N excess in branches of K28 at the second cutting, both the L. leucocephala isolines showed similar patterns of total N, fixed N₂, and N from fertilizer distribution in different parts of the plant at each cutting. The Rhizobium strain did not influence the partitioning of ¹⁵N among the different plant parts. Significant differences in ¹⁵N enrichment occurred in different parts. Live nodules of both isolines showed the lowest atom % ¹⁵N excess values (0.087), followed by leaves (0.492), branches (0.552), stems (0.591), and roots (0.857). The roots contained about 60% of the total plant N and about 70% of the total N derived from fertilizer over the successive cuttings. The total N₂ fixed in the roots was about 60% of that fixed in the whole plant, while the shoots contained only 20% of the fixed N₂. We conclude that N reserves in roots and nodules constitute another N source that must be taken into account when estimating fixed N₂ or the N balance after pruning or cutting plants. ¹⁵N enrichment declined up to about fivefold in the reference and the N₂-fixing plants over 24 weeks following the ¹⁵N application. The proportion and the amounts of N derived from fertilizer decreased, while the amount derived from N₂ fixation increased with time although its proportion remained constant.