Physiological but not morphological adjustments along latitudinal gradients in a human commensal species,the Eurasian tree sparrow

Human commensal species take advantage of anthropogenic conditions that are less likely to be challenged by the selective pressures of natural environments. Their morphological and physiological phenotypes can therefore dissociate from habitat characteristics. Understanding how these species adjust their morphological and physiological traits across latitudinal gradients is fundamental to uncovering the eco-physiological strategies underlying coping mechanisms. Here, we studied morphological traits in breeding Eurasian tree sparrows (ETSs; Passer montanus) among low-latitude (Yunnan and Hunan) and middle-latitude (Hebei) localities in China. We then compared body mass; lengths of bill, tarsometatarsus, wing, total body, and tail feather; and baseline and capture stress-induced levels of plasma corticosterone (CORT) and the metabolites including glucose (Glu), total triglyceride (TG), free fatty acid (FFA), total protein, and uric acid (UA). None of the measured morphological parameters varied with latitude except in the Hunan population, which demonstrated longer bills than those in other populations. Stress-induced CORT levels significantly exceeded baseline levels and decreased with increasing latitude, but total integrated CORT levels did not vary with latitude. Capture stress-induced significantly increased Glu levels and decreased TG levels, independent of site. However, the Hunan population had significantly higher baseline CORT, baseline and stress-induced FFA levels, but lower UA levels, which differed from other populations. Our results suggest that rather than morphological adjustments, physiological adjustments are mainly involved in coping mechanisms for middle-latitude adaptation in ETSs. It is worth investigating whether other avian species also exhibit such dissociation from external morphological designs while depending on physiological adjustments.     

A serious disease of seedling rambutan caused by Pseudocercospora nephelii sp. nov.

Pseudocercospora nephelii is described from necrotic lesions on leaves of Nephelium lappaceum seedlings in Brunei, sometimes causing complete defoliation and death. The pathogen also occurs in Sabah and Selangor in Malaysia. Recommendations for control include treatment with mancozeb or benomyl.     

种植密度对玉米-大豆带状间作下大豆光合、产量及茎秆抗倒的影响

【目的】阐明玉米-大豆带状间作下大豆植株冠层在不同种植密度下的光环境变化规律,明确种植密度对间作大豆叶片光合特性、产量形成及茎秆抗倒的影响,为构建寡日照地区间作大豆合理群体密度提供理论参考。【方法】本研究以大豆（川豆-16）和玉米（正红-505）为试验材料。采用双因素随机区组设计,主因素为种植方式,设玉米-大豆带状间作和大豆带状单作2个水平,副因素为大豆的3个种植密度（PD1=17株/m²,PD2=20株/m²,PD3=25株/m²),研究种植密度对间作大豆冠层内部光环境变化、叶片光合特性、植株生长动态、田间倒伏率及产量构成等的影响。【结果】2年结果表明,在玉米-大豆带状间作系统中,大豆生长中后期受高位作物玉米遮荫和自荫性增加的影响,其植株群体冠层内部的光合有效辐射（PAR）、叶面积指数（LAI）、叶片光合能力、分枝数及产量显著降低,但受玉米影响的程度因大豆种植密度的不同而不同。在间作模式下,PD1和PD2处理的大豆植株群体冠层光合有效辐射比PD3处理分别增加了45.4%和24.8%,净光合速率分别增加了46.1%和12.3%,单株有效荚数分别增加了53.2%和27.2%,单株分枝数分别增加了270.4%和140.9%,田间倒伏率分别降低了50.3%和19.3%。相关性分析发现,间作大豆的田间倒伏率与冠层内部光合有效辐射、叶片净光合速率、茎秆抗折力、茎叶干物质比、单株分枝数及单株有效荚数呈显著负相关,与株高、叶面积指数和单株无效荚数呈显著正相关。【结论】在玉米-大豆带状间作模式下,20株/m²的大豆密度（PD2）有利于创造良好的群体冠层内部光环境,降低植株田间大豆倒伏率,增加光合产物积累,从而提高大豆产量。     

Using leaf tip necrosis as a phenotypic marker to predict the presence of durable rust resistance gene pair <Emphasis Type="Italic">Lr34</Emphasis>/<Emphasis Type="Italic">Yr18</Emphasis> in wheat

Fifty wheat varieties along with Jupateco-73 and Morocco were studied for the expression of leaf tip necrosis (LTN), a trait linked with the durable rust resistance gene pair Lr34/Yr18. LTN was frequent (i.e., ≥6) in nine replications of a field experiment over 3 years in 17 genotypes, and the varieties were considered positive for LTN. In molecular analyses of these varieties, having relative severity values up to 78 for yellow rust and 45 for leaf rust, the 150-bp Lr34/Yr18-linked allele was consistently amplified. Expression of LTN in six of nine replications is an appropriate threshold for predicting the presence of Lr34/Yr18 gene pair, and genotypes can be selected using this trait.     

CRUSTING OF RIVER ESTATE SOIL, TRINIDAD, AND ITS EFFECT ON GASEOUS DIFFUSION, PERCOLATION, AND SEEDLING EMERGENCE

The River Estate Loam in Trinidad is micaceous. It is weakly structured and prone to surface crusting which results in decreased gaseous diffusion, infiltration- percolation, and seedling emergence. Mulching with ‘Encap’ (a liquid petroleum product) increased infiltration but not seedling emergence whereas ‘Krilium’ (sodium polyacrilonitrile) was more effective in improving seedling emergence. Bagasse mulch had a beneficial effect on infiltration but in common with pen manure was not very effective in aiding seedling emergence. Thin section examination showed that the uncrusted soil had an open structure with a large volume of pores, but, on crusting, the particles became densely packed with negligible air-spaces. Soil particles on die surface of the crust showed some degree of orientation but below the surface there was no such tendency, although particles coalesced with negligible air-spaces. The liquid petroleum mulch prevented crust formation and maintained a stable soil structure.     

DISPERSION, MECHANICAL COMPOSITION, AND FRACTIONATION OF WEST INDIAN VOLCANIC YELLOW EARTH SOILS (ANDEPTS)

Methods of dispersion used in Japan and New Zealand for soils formed on recent volcanic ash (Andepts) which involved adjusting the pH of organic matterfree soil suspensions to 4 or 10·5 were not effective on similar soils in the Caribbean. Partial dispersion was obtained by adjusting the pH to between 2 and 3 but lower (down to pH 1) and higher (up to pH 11·1) pH values were ineffective. Substantial amounts of Al dissolved at pH 1–3 probably as a result of some disintegration of the allophanoid minerals. Zirconium nitrate solutions were very efficient in causing dispersion, a concentration of 12 me Zr being necessary for complete dispersion of 20 g samples of soil. Excess Zr did not adversely affect dispersion but resulted in depression of pH of the suspensions. The high ionic charge, small atomic radius, and low ionization potential of Zr apparently resulted in saturation of the cation exchange capacity and some isomorphous substitution of Al leading to a net positive charge of the clay and an increase in anion exchange capacity. This was considered to be responsible for dispersion.     

Field evaluation of some bait additives against Indian crested porcupine (Hystrix indica) (Rodentia: Hystricidae)

This research study evaluated the effect of different additives on the bait consumption by Indian crested porcupine, a serious forest and agricultural pest, under field conditions. Different additives (saccharin, common salt, bone meal, fish meal, peanut butter, egg yolk, egg shell powder, yeast powder, mineral oil and coconut oil) at 2 and 5% each were tested for their relative preference, using groundnut–maize (1:1) as basic bait. All the additives were tested under a no‐choice test pattern. For control tests, no additive was mixed with the basic bait. Saccharin at 5% concentration significantly enhanced the consumption of bait over the basic bait, while 2% saccharin supplemented bait resulted in a non‐significant bait consumption. All other additives did not enhance the consumption of the bait material; rather, these worked as repellents. However, the repellency was lowest with the common salt, followed by egg yolk, egg shell powder, bone meal, peanut butter, mineral oil, fish meal and yeast powder, while coconut remained the most repellent compound. The present study suggested that groundnut–maize (1:1) supplemented with 5% saccharin was the preferred bait combination, and can be used with different rodenticides for the management of Indian crested porcupine.     

Nitrogen management improves lodging resistance and production in maize (Zea mays L.) at a high plant density

Lodging in maize leads to yield losses worldwide.  In this study, we determined the effects of traditional and optimized nitrogen management strategies on culm morphological characteristics, culm mechanical strength, lignin content, root growth, lodging percentage and production in maize at a high plant density.  We compared a traditional nitrogen (N) application rate of 300 kg ha^–1 (R) and an optimized N application rate of 225 kg ha^–1 (O) under four N application modes: 50% of N applied at sowing and 50% at the 10th-leaf stage (N1); 100% of N applied at sowing (N2); 40% of N applied at sowing, 40% at the 10th-leaf stage and 20% at tasseling stage (N3); and 30% of N applied at sowing, 30% at the 10th-leaf stage, 20% at the tasseling stage, and 20% at the silking stage (N4).  The optimized N rate (225 kg ha^–1) significantly reduced internode lengths, plant height, ear height, center of gravity height and lodging percentage.  The optimized N rate significantly increased internode diameters, filling degrees, culm mechanical strength, root growth and lignin content.  The application of N in four split doses (N4) significantly improved culm morphological characteristics, culm mechanical strength, lignin content, and root growth, while it reduced internode lengths, plant height, ear height, center of gravity height and lodging percentage.  Internode diameters, filling degrees, culm mechanical strength, lignin content, number and diameter of brace roots, root volume, root dry weight, bleeding safe and grain yield were significantly negatively correlated with plant height, ear height, center of gravity height, internode lengths and lodging percentage.  In conclusion, treatment ON4 significantly reduced the lodging percentage by improving the culm morphological characteristics, culm mechanical strength, lignin content, and root growth, so it improved the production of the maize crop at a high plant density.     

The first report on serotyping of bluetongue virus in small ruminants of Khyber Pakhtunkhwa province,Pakistan

Bluetongue virus (BTV), a member of Orbivirus genus (family Reoviridae), is a non-contagious infection of domestic and wild ruminants. The current study was designed to detect various serotypes of BTV in small ruminants of Khyber Pakhtunkhwa (KPK) province of Pakistan, along with their effects on hemato-biochemical parameters. A total of 408 serum samples in four districts (Mansehra, Abbottabad, Swabi, and Kohat) of KPK from small ruminants were screened based on competitive ELISA (cELISA). A total of 204 (50%) samples were found positive for BTV group–specific antibodies. The seropositive samples were processed for the detection of BTV serotypes through real-time polymerase chain reaction (qPCR). Out of 204 cELISA-positive samples, 60 (29.41%) were found positive through qPCR. Three serotypes [6, 8, 9] were detected from Mansehra District and two from Kohat [2, 8] and Abbottabad [6, 8], while only one from Swabi [8]. The serotype “8” was found consistently in all the four study districts. A significant (p?<?0.05) increase in the level of blood urea nitrogen (BUN) and alkaline phosphatase (ALP) was recorded in goats, whereas aspartate aminotransferase (AST) in sheep infected with BTV, compared to healthy animals. The hematological parameters showed significantly (p?<?0.05) raised total leucocyte count (TLC) in both sheep and goats, whereas only hematocrit (HCT) value was increased significantly (p?<?0.05) in infected sheep. This is the first report on serotyping of BTV among small ruminants in Pakistan.

     

Broadening the genetic base of <Emphasis Type="Italic">Brassica napus</Emphasis> canola by interspecific crosses with different variants of <Emphasis Type="Italic">B. oleracea</Emphasis>

Broadening the genetic base of the C genome of Brassica napus canola by use of B. oleracea is important. In this study, the prospect of developing B. napus canola lines from B. napus?×?B. oleracea var. alboglabra, botrytis, italica and capitata crosses and the effect of backcrossing the F₁’s to B. napus were investigated. The efficiency of the production of the F₁’s varied depending on the B. oleracea variant used in the cross. Fertility of the F₁ plants was low—produced, on average, about 0.7 F₂ seeds per self-pollination and similar number of BC₁ seeds on backcrossing to B. napus. The F₃ population showed greater fertility than the BC₁F₂; however, this difference diminished with the advancement of generation. The advanced generation populations, whether derived from F₂ or BC₁, showed similar fertility and produced similar size silique with similar number of seeds per silique. Progeny of all F₁’s and BC₁’s stabilized into B. napus, although B. oleracea plant was expected, especially in the progeny of F₁ (ACC) owing to elimination of the A chromosomes during meiosis. Segregation distortion for erucic acid alleles occurred in both F₂ and BC₁ resulting significantly fewer zero-erucic plants than expected; however, plants with?≤?15% erucic acid frequently yielded zero-erucic progeny. No consistent correlation between parent and progeny generation was found for seed glucosinolate content; however, selection for this trait was effective and B. napus canola lines were obtained from all crosses. Silique length showed positive correlation with seed set; the advanced generation populations, whether derived from F₂ or BC₁, were similar for these traits. SSR marker analysis showed that genetically diverse canola lines can be developed by using different variants of B. oleracea in B. napus?×?B. oleracea interspecific crosses.