Water relations, gas exchange characteristics, and the level of some metabolites in two cultivars of spring wheat under different N regimes

Twenty eight-day old plants of two spring wheat cultivars differing in salinity tolerance were subjected to varying levels of nitrogen (56, 112, and 224 mg N·kg⁻¹ soil) for 42 days. Both cultivars performed differently under varying soil N levels in terms of growth, and grain yield and yield components. Nitrogen levels, 112 and 224 mg·kg⁻¹ soil, caused maximal growth in Sarsabz and Barani-83, respectively. Cv Sarsabz maintained higher leaf water and turgor potentials, but lower leaf osmotic potential than those of Barani-83 at all external N regimes. Sarsabz had higher Chl a, Chl b and carotenoids contents in leaves than those in Barani-83 at 56 and 112 mg N·kg⁻¹ soil. Sarsabz had higher contents of leaf soluble proteins, soluble sugars, and free amino acids than those in Barani-83 at all external N levels. In Barani-83 net CO₂ assimilation rate remained almost unchanged, whereas in Sarsabz it decreased consistently with increase in external N level. The better growth performance of Sarsabaz as compared to Barani-83 under varying soil N levels except 224 mg N·kg⁻¹ soil was associated with maintenance of high leaf turgor potential but not with net CO₂ assimilation rate.     

白珠树属5种药用植物木脂素苷含量的比较

Ｔ.Ｚ.Ｈｓｕ＆Ｒ.Ｃ.Ｆａｎｇ〕是治疗风湿病的民族药,目前还没有评价质量的定性和定量方法。一般认为水杨酸甲酯是可能的有效成分,但根据作者的最新研究[1～3],建议暂用滇白珠木脂素苷含量作滇白珠的质量标准,同时建立[4]和改进[5]了分析木脂素苷的高效液相法,并研究了木脂素苷在滇白珠体内的分布特点及季节和地区对含量的影响[6]。根据作者对白珠树属(ＧａｕｌｔｈｅｒｉａＫａｌｍｅｘＬ.)的研究[7],发现具有抗风湿活性是该属许多植物的一个共同特点,其中至少有15种(变种)植物在民间被用于风湿病治疗[8],为了分析和比较这些植物在相关化…     

Short-term foraging patterns of individual cornetfish, Fistularia commersonii, based on stomach content analysis

Stomach contents of 75 specimens of the cornetfish Fistularia commersonii, collected in shallow water off Kuchinoerabu-jima Island, southern Japan were analyzed. Many fish contained multiple prey. The prey were mostly fish, grouped into two types, pelagic and reef fishes. The size of prey increased as the size of F. commersonii increased. All the small individuals (<50 cm SL) had fed on only small reef fish. However, most of the large individuals (>50 cm SL) had fed on either prey type. Both pelagic and reef fishes usually occurred simultaneously in shallow water, suggesting that most of the large cornetfish may selectively hunt either type of prey. Received: February 27, 2001 / Revised: September 11, 2001 / Accepted: October 10, 2001     

Influence of host plants on development, fecundity and egg hatchability of the arctiid moth Diacrisia casignetum

Measurements were made of the differences between sunflower and climbing hempweed leaves for development, fecundity and egg hatchability of Diacrisia casignetum Kollar. Developmental time and weight gains of sunflower-fed larvae were respectively longer and greater than those of hempweed-fed ones. The development time and weight gain, attributable to differences in host plants, were statistically heterogeneous (P<0.05-<0.10). Relative fecundity and egg hatchability of sunflower reared insects were greater than those of hempweed reared ones, and these were also statistically heterogeneous (P<0.1 and <0.05, respectively). Hempweed leaves contained relatively high titres of phenols and low ratios of proteins to phenols. Ovaries were heavier in insects reared on sunflower than on hempweed, whereas the level of phenols incorporated into the ovary was higher in insects fed on hempweed than those on sunflower. The differences in these parameters may be due to variations in nutritional quality of these hosts and incorporation of ingested phenolic materials to ovary and insect biomass.

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Résumé L'étude a porté sur l'évaluation de l'influence des feuilles de tournesol (Helianthus annuus) et de Mikana cordata sur le développement, la fécondité et l'éclosion des oeufs de D. casignetum Kollaz. La durée de développement et le gain de poids sur tournesol étaient plus importants que sur M. cordata. La durée de développement était statistiquement hétérogène (P<0.05), ce qui peut être dû à des différences entre plantes. La fécondité et le taux d'éclosion chez les insectes élevés sur tournesol étaient plus élevés que ceux observés sur M. cordata, dont les résultats étaient aussi hétérogènes (P<0.1 et<0.05 respectivement). Les feuilles de M. cordata contenaient des taux relativement élevés de phénols et des rapports protéines sur phénols bas. Tout ceci suggère que les différences observées sont attribuables à des variations dans la qualité nutritive de ces hôtes et dans l'incorporation à la biomasse de l'insecte de matériaux phénologiques ingérés.

     

Evidence for diet partitioning among three coexisting native freshwater fishes in South Africa's Cape Fold Ecoregion

The partitioning of limited resources commonly explains how different species can coexist within the same ecological community. In this 2010 study, the diets of three coexisting freshwater fishes (Cape galaxias Galaxias zebratus, n = 27; Cape kurper Sandelia capensis, n = 60; Breede River redfin Pseudobarbus burchelli, n = 77) were characterised and compared in three headwater streams in South Africa's Cape Fold Ecoregion using gut contents and stable isotope analyses. These data were analysed to ascertain whether the three species exploit distinct trophic niches. Both approaches provided evidence that these species occupy different trophic niches, though with some overlap. However, dietary differences among sites were not consistent and were probably influenced by site-specific factors like resource availability. Pseudobarbus burchelli had a broader niche breadth at Tierkloof Stream than the other two species, but not at Waaihoek or Tierstel Streams. Our results also suggest that P. burchelli consumed a more omnivorous diet than do the other two species, whereas S. capensis occupied a higher trophic position than the other two species and consumed vertebrates. Our findings suggest that these species occupy non-equivalent feeding niches in Cape Fold Ecoregion headwater streams, and that diet partitioning might facilitate their coexistence in these systems.     

Dream content: Reflections of the emotional and psychological states of earthquake survivors.

This study investigated dream narratives as reflections of the emotional and psychological states of earthquake survivors. Dreams and dreams imagery have reportedly been affected by the emotional and psychological trauma that the dreamer goes through. Dream narratives and dream content ratings used in earlier studies were utilized in this study. Narratives and content ratings were obtained from a sample of 27 volunteer survivors of the October 8, 2005 earthquake in Pakistan (Azad Kashmir area) and 27 volunteer controls from similar demographics. Three independent raters judged the dream narratives and dream content ratings. The judges rating were highly congruent (86.05). Findings revealed that the survivor group had more vivid, unpleasant, horrifying, and hostile dreams compared with the control group. However, there were no significant gender differences. The data suggest that a closer study of dreams can be used to understand the underlying trauma for effective interventions. In addition, interesting emergence of recurrent dreams was seen, which will be independently studied in future. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rumen Ciliate Fauna of Alaskan Moose (Alces americana), Musk-Ox (Ovibos moschatus) and Dall Mountain Sheep (Ovis dalli)*

Total numbers, generic distribution and percentage species distribution were determined for the ciliate protozoa in rumen contents obtained from Alaskan moose (Alces americana), musk-ox (Ovibos moschatus) and Dall mountain sheep (Ovis dalli). The musk-ox has a fauna somewhat similar to that previously observed in reindeer and caribou. In contrast, only protozoa in the genus Entodinium were observed in moose, while Dall mountain sheep have a fauna unique among Alaskan ruminants studied to date. Other than Entodinium exiguum which was common to all animals, only 2 additional species of Entodinium, observed in the moose and musk-ox, occurred in more than one animal species. Four new species of protozoa are described, Entodinium dalli sp.n., Entodinium constrictum sp.n. and Polyplastron alaskum sp.n. from the Dall mountain sheep and Entodinium alces sp.n. from moose.     

Soil erosion and deposition effects on surface characteristics and pearl millet growth in the West African Sahel†

It is well known that surface mulched crop residues (CR) lead to large yield increases of pearl millet (Pennisetum glaucum L.) on acid sandy soils of the West African Sahel. This effect is generally attributed to mulch-induced changes in chemical properties of the surface soil and the protection of millet seedlings from erosive sand storms. However, previous research has failed to separate the anti-erosive effects of CR on plant growth from chemical effects due to the release of nutrients during CR decomposition. To this end a mulching trial with surface applied millet stalks at a rate of 2000 kg ha^-1, an equivalent 10% surface coverage obtained by inert polyethylene (PE) tubes and a bare control treatment was conducted from 1992 to 1994 on an acid sandy soil in southwest Niger. Across treatments, sand flux at 0.1 m height was more than twice as high in the rainy seasons than in the dry months and mulching reduced sand flux by between 25 and 50% during rainy season storms compared with 67% during the dry season. Over the 21 months measurement period, cumulative erosion by wind and water was almost 270 t ha^-1 of soil in unmulched control plots. In mulched plots, in contrast, between 160 and 200 t ha^-1 of soil was deposited. Surface soil temperature at 0.01 m depth reached above 40 °C in bare plots but was up to 4 °C lower with CR. Mulch reduced soil penetration resistance at 0–0.02 m and 0–0.05 depth by more than half and decreased runoff leading to higher water contents at flowering and grain filling in the upper 0.3 m soil layers in 1993 and throughout the entire profile in 1994, a year with particularly high rainfall. Both mulch types were similarly effective in increasing final stand density of millet in the first two years between 5 and 23% compared with bare control plots. Relative to the bare control CR mulch effects on total dry matter of millet at harvest increased from 35% in 1992 and 108% in 1993 to 283% in 1994, whereas PE mulch led to respective relative increases in dry matter of only 6, 44 and 13%. In 1992 and 1993, CR mulch increased total nutrient uptake of millet at harvest by between 34 and 86% for nitrogen (N), between 31 and 162% for P and between 56 and 126% for potassium (K). These differences were mostly the result of differences in total dry matter and only to a smaller part due to changed nutrient concentrations in plants. This revised version was published online in June 2006 with corrections to the Cover Date.     

The Content Levels of Chemical Elements of Plants in the Castanozems Typical Steppe Zone of Nei Monggol

The contents of N, P, K, Ca, S, Fe, Al, Si, Na, of 122 plant species in the XiLin River valley in Nei Monggol were studied. These results have shown as follows: 1. The contents of N, P. K, Ca, S, Fe, Al, Si, Na of 122 plants belong to three levels: N, K, Ca are 101-100(%) P, S, Si, Na are 100-10-1(%); Fe, A1 are 10-1-10-2(%). 2. The contents of chemical elements of 122 plants were divided into three levels (high, middle and low content). The range of the content and the number of plants in each level were obtained.     

斑鳢、乌鳢及其杂种细胞核DNA流式含量分析

以斑鳢(Channa maculata)、乌鳢(C.argus)及其正交杂种斑乌鳢(斑鳢♀×乌鳢♂)和反交杂种乌斑鳢(乌鳢♀×斑鳢♂)的红细胞为材料,以鸡(Gallus gallus)血细胞为DNA标准(2.5 pg/2c,2c指2倍体),采用流式细胞仪测定了这4种鱼的细胞核DNA含量。斑鳢、乌鳢、斑乌鳢及乌斑鳢这4种鱼血细胞DNA的绝对含量分别为(1.488±0.035)pg/2c、(1.489±0.034)pg/2c、(1.522±0.077)pg/2c和(1.520±0.033)pg/2c。斑鳢和乌鳢的细胞核DNA含量差异不显著(P0.05),斑鳢和乌鳢与两种杂交鳢的DNA含量差异显著(P0.05),两种杂交鳢之间的细胞核DNA含量差异不显著(P0.05)。杂交鳢细胞核DNA含量显著高于亲本,可以作为杂种鉴定的依据。