Phenotypic Changes in Grain Sorghum Over the Last Five Decades

Sorghum [Sorghum bicolor (L.) Moench] is a drought‐tolerant crop, and its productivity in rain fed environments has increased since the 1950s. This increase is due to changes in agronomic practices and hybrid improvement. The objective of this study was to determine what aspects of grain sorghum morphology, physiology and water use have changed with hybrid improvement and might have contributed to this yield increase. A 2‐year greenhouse experiment was conducted with one hybrid from each of the past five decades. The hybrids were studied in well‐watered and pre‐ and post‐flowering water deficit conditions. Total water use, transpiration, stomatal conductance and photosynthesis were measured during the growing period. Biomass and biomass components were measured at harvest. There was no consistent change in the leaf physiological parameters resulting from hybrid advancement. In contrast, total water use increased in rate of 8.5 cm³ kg soil^?1 year^?1 from old to new hybrids in the well‐watered treatments. Root biomass also increased in rate of 0.2 g plant^?1 year^?1. Leaf biomass and panicle length also was greater for the newest compared with the older hybrids. Hybrid advancement was related to increase in panicle length but decrease in peduncle length. Results indicated that hybrid development programmes created hybrids with improved drought avoidance, due to better root density of newly released hybrids, or hybrids with better resource use which ultimately increased yield under rain fed conditions.     

慢性肾功能不全患者感染的临床特点及其相关因素分析

目的:探讨慢性肾功能不全患者感染的临床特点及其相关因素.方法:对600例次慢性肾功能不全患者(血液透析180例次,腹膜透析110例次,非透析患者310例次)的住院资料进行回顾性分析,对感染部位、病原体、原发病因、肾功能状态及营养状况进行分析.结果:①慢性肾功能不全代偿期和失代偿期患者感染率(26.6%)明显低于肾功能衰竭期和尿毒症期的患者(46.8%)(P＜0.05);原发病中糖尿病感染率最高;②细菌培养328例次,其中阳性268例次,以革兰氏阴性杆菌常见(46.3%);③感染组中血红蛋白、血清白蛋白显著低于非感染组(P＜0.05);④血液透析患者的感染部位主要为肺部(46.4%)和静脉导管(21.3%),腹膜透析患者感染部位主要为腹腔;⑤血液透析和腹膜透析患者总体感染率差异无显著性(P＞0.05),但是血液透析患者乙型肝炎病毒携带率(18.3%)和丙型肝炎病毒阳性率(8.7%)均高于腹膜透析患者(P＜0.05),而腹膜透析患者腹腔真菌感染率却明显高于血液透析患者(P＜0.05).结论:慢性肾功能不全患者感染率较高,糖尿病感染多见.贫血、低蛋白血症、肾功能损害的严重程度、高龄等因素均可能增加慢性肾功能不全患者感染的机会.血液透析和腹膜透析患者总体感染率差异无显著,但血液透析患者乙型肝炎病毒携带率和丙型肝炎病毒阳性率均显著高于腹膜透析患者,而腹膜透析患者腹腔真菌感染率却明显高于血液透析患者.     

Study of kernel structure of high-amylose and wild-type rice by X-ray microtomography and SEM

Rice kernels of a transgenic high-amylose rice line and its wild type were examined by a high-resolution X-ray microtomography (XMT) and an environmental scanning electron microscope. Two-dimensional (2-D) cross-sectional images and 3-D objects from XMT were reconstructed and analyzed to elucidate their structural features. The lack of two isoforms of starch branching enzyme, termed SBEI and SBEIIb in high-amylose rice (HAR), resulted in a distinctly different grain inner density than wild-type rice (WTR). HAR had smaller, elongated starch granules with air spaces inside the kernels resulting in an opaque grain, whereas WTR had a tight endosperm with little air space and polygonal starch granules. XMT allowed a full 3-D characterization of the rice kernel structure and revealed that air space distribution was not uniform in the HAR kernel.     

Synthesis and Antitumor Activities of Derivatives of the Marine Mangrove Fungal Metabolite Deoxybostrycin

Deoxybostrycin (1) is an anthraquinone compound derived from the marine mangrove fungus Nigrospora sp. No. 1403 and has potential to be a lead for new drugs because of its various biological properties. A series of new derivatives (2–22) of deoxybostrycin were synthesized. The in vitro cytotoxicity of all the new compounds was tested against MDA-MB-435, HepG2 and HCT-116 cancer cell lines. Most of the compounds exhibit strong cytotoxicity with IC₅₀ values ranging from 0.62 to 10 μM. Compounds 19, 21 display comparable cytotoxicity against MDA-MB-435 to epirubicin, the positive control. The primary screening results indicate that the deoxybostrycin derivatives might be a valuable source of new potent anticancer drug candidates.     

Physical properties of pellets made from sorghum stalk, corn stover, wheat straw, and big bluestem

Densification of biomass feedstocks, such as pelleting, can increase bulk density, improve storability, reduce transportation costs, and make these materials easier to handle using existing handling and storage equipment for grains. The objectives of this research were to study (1) the physical properties of pellets made from corn stover, sorghum stalk, wheat straw, and big bluestem, (2) the effect of moisture content on bulk density, true density, and durability of the biomass pellets, and (3) the effect of hammer mill screen size and die thickness on bulk density, true density, and durability of the pellets. Biomass pelleting can significantly improve the bulk density from 47 to 60 kg/m³ for biomass grinds to 360 to 500 kg/m³ for biomass pellets. Of the four types of biomass pellets, wheat straw pellets had the highest bulk density value of 495.8 kg/m³, and sorghum stalk pellets had the lowest bulk density value of 365.2 kg/m³. An increase in moisture level resulted in a decrease in bulk density and true density of the pellets. The effect of moisture content on durability of the pellets made from corn stover, wheat straw, and big bluestem showed a similar trend; the maximum durability value was 96.8% at the equilibrium moisture content (EMC) range of 9% (d.b.) to 14% (d.b.) for corn stover and wheat straw, and 9% (d.b.) to 11% (d.b.) for big bluestem. A further increase in EMC value resulted in a decrease in pellet durability. For sorghum stalk pellets, the durability value increased initially with increased EMC and reached a maximum of 89.5% at EMC values between 14% (d.b.) and 16% (d.b.). Use of a larger hammer mill screen size (from 3.2 mm to 6.5 mm screen openings) resulted in increases of bulk density, true density, and durability of biomass pellets, but not in significant levels. Use of a thicker die size (from 31.8 mm to 44.5 mm in thickness) resulted in significant increase of bulk density, true density, and durability of biomass pellets.     

Soil Temperature and Planting Depth Effects on Tef Emergence

Tef [ Eragrostis tef (Zucc.) Trotter] is an annual C4 grass crop that originated in Ethiopia. It has potential as a grain crop in the Great Plains because of its tolerance to drought and high temperatures. In Ethiopia, tef seed is typically broadcast on the soil surface and lightly incorporated. Shallow planting depths are used because the seed is very small and emergence can be limited by soil crusting. If planting equipment is to be used, planting depth may be important for successful tef production. The objective of this study was to identify optimal depths and soil temperatures to aid in developing tef planting recommendations for the central Plains. Tef was planted at five depths (0, 0.6, 1.3, 2.5 and 5.0 cm) in pots filled with a silt loam soil, and pots were placed in growth chambers at four temperature regimes (day/night: 15/19 °C; 19/23 °C; 23/27 °C and 27/31 °C). No plants emerged from the 5.0-cm depth, so this depth was not included in the analysis. Emergence was greatest for planting depths of 0.6 and 1.3 cm and lower at 0 and 2.5 cm depths. Temperature did not affect final emergence, measured 21 days after planting (DAP), but did influence emergence rates during the first 9 DAP. Plant dry matter production increased as planting depth increased, but plant dry matter per pot was not different among planting depths greater than 0.9 cm, suggesting that compensation between plants across different plant densities began early in the plants' life cycles. Our results show that tef seed can emerge from depths between 0.6 and 1.3 cm and that soil temperatures below 19 °C can slow emergence but should not affect final stands.     

不同供水条件下小麦不同绿色器官的气孔特性研究

为了考察小麦叶片与非叶器官气孔结构特性的差异及其对供水条件的反应，本研究设置不同灌水处理，利用电镜观察小麦灌浆期不同绿色器官的气孔分布和结构特征，并分析其与气孔特性指标间的关系。结果表明，在不同灌水处理下看到各非叶器官（穗、旗叶鞘和穗下节间）均分布着气孔，但其数目少于旗叶叶片。护颖仅在远轴面存在气孔；外稃在多水条件下（4水处理）近轴面出现较多气孔，而远轴面看不到气孔，但在水分胁迫（无水处理）条件下，气孔却出现在远轴面而不在近轴面；在不同水分处理下均观察到芒上明显的气孔分布。从气孔大小看，穗各部分（护颖、外稃、内稃和芒）略小于其他器官。随着灌水次数的减少，各器官气孔密度呈增大趋势，气孔器及气孔孔径表现出长度增加、宽度减小的特征。限水灌溉下非叶器官（穗、旗叶鞘和穗下节间）在籽粒灌浆期气孔导度、蒸腾速率和光合速率的稳定性高于叶片。相关分析表明，不同器官的气孔导度与蒸腾速率均呈显著正相关，非叶器官气孔导度与光合速率的相关程度明显低于叶片。说明在干旱少水条件下，叶与非叶器官蒸腾作用均会减弱，叶片光合速率亦相应降低，而非叶器官光合速率可能保持相对稳定，可相对提高其水分利用效率。     

Population dynamics,phenology, and overwintering of <Emphasis Type="Italic">Bactrocera dorsalis</Emphasis> (Diptera: Tephritidae) in Hubei Province,China

Since 2004 the oriental fruit fly, Bactrocera dorsalis (Hendel) has become widespread and economically important in Wuhan, Hubei Province, central China. In this article, the population dynamics of B. dorsalis were monitored using methyl eugenol-baited traps during 2008–2009 in Wuhan. Adults were captured from early July to the end of December in a citrus orchard and peaked in October and early November. Adult population peak coincided with the ripeness period of sweet oranges in October. Infestation with B. dorsalis was more serious in 2009 than in 2008. Field surveys of host plants for this fly species combined with rearing experiments indicated that pear was the first host plant infested by B. dorsalis. We recorded the following host shift pattern: pear (Pyrus communis L.), jujube (Zizyphus jujuba L.), persimmon (Diospyros kaki L.), and sweet orange (Citrus unshiu Marcor). Our findings suggest that B. dorsalis completes four to five generations per year in this area and most serious damage occurred in the 4th generation in the citrus orchards. The availability of preferred host fruits and the low winter temperature are key factors influencing population fluctuations. Overwintering potential experiments of adults, larvae, and pupae were also carried out in the field. Results suggest that a small proportion of pupae were able to survive winter in Wuhan and emerged successfully the following year. Practical and theoretical implications of the results regarding the invasion potential and management strategy of B. dorsalis in Hubei Province are discussed.     

Three bianthraquinone derivatives from the mangrove endophytic fungus Alternaria sp. ZJ9-6B from the South China Sea

Three new bianthraquinone derivatives, alterporriol K (1), L (2) and M (3), along with six known compounds were obtained from extracts of the endophytic fungus Alternaria sp. ZJ9-6B, isolated from the mangrove Aegiceras corniculatum collected in the South China Sea. Their structures were elucidated by one- and two-dimensional NMR spectroscopy, MS data analysis and circular dichroism measurements. Compounds 1, 2 and 3 were first isolated alterporriols with a C-2–C-2′ linkage. The crystallographic data of tetrahydroaltersolanol B (7) was reported for the first time. In the primary bioassays, alterporriol K and L exhibited moderate cytotoxic activity towards MDA-MB-435 and MCF-7 cells with IC₅₀ values ranging from 13.1 to 29.1 μM.     

Secondary Metabolites of a Mangrove Endophytic Fungus Aspergillus terreus (No. GX7-3B) from the South China Sea

The mangrove endophytic fungus Aspergillus terreus (No. GX7-3B) was cultivated in potato dextrose liquid medium, and one rare thiophene compound (1), together with anhydrojavanicin (2), 8-O-methylbostrycoidin (3), 8-O-methyljavanicin (4), botryosphaerone D (5), 6-ethyl-5-hydroxy-3,7-dimethoxynaphthoquinone (6), 3β,5α-dihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (7), 3β,5α,14α-trihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (8), NGA0187 (9) and beauvericin (10), were isolated. Their structures were elucidated by analysis of spectroscopic data. This is the first report of a natural origin for compound 6. Moreover, compounds 3, 4, 5, 7, 8 and 10 were obtained from marine microorganism for the first time. In the bioactive assays in vitro, compounds 2, 3, 9 and 10 displayed remarkable inhibiting actions against α-acetylcholinesterase (AChE) with IC₅₀ values 2.01, 6.71, 1.89, and 3.09 μM, respectively. Furthermore, in the cytotoxicity assays, compounds 7 and 10 exhibited strong or moderate cytotoxic activities against MCF-7, A549, Hela and KB cell lines with IC₅₀ values 4.98 and 2.02 (MCF-7), 1.95 and 0.82 (A549), 0.68 and 1.14 (Hela), and 1.50 and 1.10 μM (KB), respectively; compound 8 had weak inhibitory activities against these tumor cell lines; compounds 1, 2, 3, 4, 5, 6 and 9 exhibited no inhibitory activities against them.