浅论西宁引种栽培银杏的可行性

银杏是古老的孑遗植物,名贵树种,引种成功会带给西宁市无限活力,让西宁市的城市绿化上一个新台阶.     

农户田块尺度冬小麦不同产量水平土壤细菌群落差异

为了明确土壤细菌群落对小麦产量的影响，以河南省济源市冬小麦种植户田块为研究对象，通过采集扬花期麦田土壤样品，利用Illumina高通量测序技术测定细菌16S rRNA V3+V4区序列，分析冬小麦不同产量水平土壤的细菌群落差异。结果表明，高产组土壤铵态氮含量显著高于低产组(P<0.05),土壤有机质含量、速效钾含量、有效磷含量、硝态氮含量、pH值在组间均无显著差异，土壤酸性磷酸酶、碱性磷酸酶、脲酶和过氧化氢酶活性在组间也均无显著差异。酸杆菌门(Acidobacteria)和变形菌门(Proteobacteria)是土壤细菌群落的主导菌门。门水平上，小麦产量与芽单胞菌门(Gemmatimonadetes)、装甲菌门(Armatimonadetes)、纤维杆菌门(Fibrobacteres)、Latescibacteria、Dadabacteria相对丰度显著相关。属水平上，Bryobacter、黄杆菌属(Flavisolibacter)、芽单胞菌属(Gemmatimonas)、丰佑菌属(Opitutus)、黏液杆菌属(Mucilaginibacter)、Dongia、Chryseo...     

FLOODING STRESS: The Effects of Planting Pattern and Water Regime on Root Morphology,Physiology and Grain Yield of Rice

Field experiments were conducted over two growing seasons to investigate the effects of variations in water regime and planting pattern on the growth of rice plant roots and shoots and on yield. Four water regimes were evaluated with split plot design: intermittent flooding during the vegetative stage only (IF‐V); intermittent flooding extending into the reproductive stage (IF‐R); not flooded (NF); and continuously flooded (CF), interacting with three different planting patterns: single seedling per hill with wider 30 × 30 cm spacing (P1); single seedling per hill with closer 20 × 20 cm spacing (P2); and three to four seedlings per hill with 20 × 20 cm spacing (P3). The treatment combination CF/P3 corresponds most closely with current conventional practice. The other combinations were evaluated to contribute to a better understanding of the effects of the two parameters studied, respectively and together. IF‐V/P1 was considered as an approximation of System of Rice Intensification (SRI) practice. This study found that the combination of singly transplanted seedlings, both P1 and P2, with the IF‐V water regime improved root length density, root physiological activity, and chlorophyll content of the upper and lower leaves, leading to higher grain yield compared with the other treatment combinations. With continuous flooding (CF), P2 gave 23 % more yield compared with the P3 planting pattern. Combining IF‐V and P2 produced 32 % more grain yield compared with the CF/P3 treatment. These results showed a synergistic effect on grain yield from reduced intra‐hill competition and IF‐V water management. In these trials, there was no significant yield difference between the IF‐V/P1 and CF/P3 treatments. Wider spacing improved the performance of individual hills when grown under IF‐V water regimes, but tiller number per unit area remained a dominant determinant of yield. The yield reduction observed for CF/P1 compared with CF/P3 indicated that in more hypoxic CF soils, denser plant populations can produce more than sparser ones, whereas the latter benefit from more aerobic soil conditions. Intermittent irrigation during the vegetative growth stage and transplanting single seedlings/hill are major elements of SRI methodology. These findings contribute to an understanding of why SRI methods can produce the higher yields reported. A consideration of the effects of interaction between planting pattern and water regime shows the need to establish empirically the optimum values for these treatments according to varietal, soil and climatic characteristics for the greatest yield response.     

中国沙棘雌雄株的染色体核型分析

为了准确了解中国沙棘雌雄株染色体核型特征,对中国沙棘(Hippophae rhamnoidessubsp.sinesis)雌雄株的染色体核型进行分析。结果表明,中国沙棘第4、5、7号染色体在雌株中属于M型染色体,在雄株中属于m型染色体,第1、39、号染色体在雌株中属于m型染色体,在雄株中属于M型染色体;雌雄株均有24条染色体,染色体均属于正中部着丝粒染色体(M)和中部着丝粒染色体(m)2种,染色体核型公式同为:2n=24=14M+10m;染色体核型属于1B型,核型不对称系数为54%,在进化上属于较原始种类。     

海南省热带饲用植物资源现状与开发对策

概述海南自然资源和热带饲用植物资源现状，分析开发热带饲用植物资源面临的问题，并提出了对策。     

Investigations on the radioactive contamination of crop plants as a result of H-bomb detonation (Part 2) Root and foliage uptake of “Bikini ash”

The Foliar Uptake by Squash Plant

The radioactive ash for experimental use, hereafter referred to as “Bikini ash”, was prepared by igniting the heavily contaminated substances on board No. 5 Fukuryu Maru at about 650°C, followed by sifting through a 100 mesh sieve. On ignition some parts of the fission products, particularly iodine, ruthenium and tellurium would have possibly been lost to the air.     

浅议文化造园

首先分析当前文化造园存在的一些问题,包括漠视园林文化和歪曲传统文化的现象,继而指出文化造园需要了解场地、尊重历史,其发展与丰富依赖于人与风景在时间长轴上的共同作用、不断积淀；最后以南宁孔庙植物景观和贵港龙蝠山庄假山的设计为例,简明阐释了在园林设计过程中如何结合实际、因地制宜,有效传承、发扬中国传统园林植物文化和山水文化.     

4种豆科牧草种子对绵羊消化道作用的反应

以4种野生豆科牧草苦豆子(Sophora alopecuroide)、线叶野豌豆(Vicia tenuifolia)、光果甘草(Glycyrrhizae glabrae)、罗马苜蓿(Medicago romanica)种子为研究对象,测定各种子在绵羊消化道作用前后的形态、生物学特性变化以及在绵羊消化道内的运移和排放规律。结果表明,4种种子排放过程均符合高斯模型,且苦豆子、线叶野豌豆、光果甘草排放峰值均出现在饲喂后24~36h,罗马苜蓿种子排放峰值则出现在18~30h。苦豆子、线叶野豌豆、光果甘草和罗马苜蓿种子总回收率分别为14.513%、4.463%、10.811%、4.608%,在绵羊消化道内的平均滞留时间分别为36.3、29.6、31.2和31.9h。除苦豆子外,其它3种植物种子在经过消化道后单粒重显著降低(P0.05),4种种子消化后的形状指数较经过消化道前显著减小。经过绵羊消化道后种皮颜色加深,纹理模糊,出现褶皱及明显侵蚀斑。与经过消化道前比较,4种植物种子经过消化道后的发芽率均有显著提高,其中发芽率提高效果最明显的时间段在消化24~48h后。消化道作用可有效打破苦豆子、线叶野豌豆、光果甘草、罗马苜蓿种子的硬实,4种植物种子均可通过绵羊消化道传播。     

Effects of Shading on Chlorophyll Content,Chlorophyll Fluorescence and Photosynthesis of Subterranean Clover

A field‐experiment (2004/2005 and 2005/2006 seasons) was conducted in the coastal plain of south‐eastern Sicily (37°03′N, 15°18′E, 15 m a.s.l.), on a Calcixerollic Xerochrepts soil, aimed at quantifying the effect of shading on chlorophyll (Chl) content, Chl fluorescence, photosynthesis and growth of subterranean clover. Four levels of photosynthetically active radiation reduction (from 0 % to 90 %) were tested on Trifolium brachycalycinum cv. ‘Clare’ and Trifolium subterraneum ecotype ‘Ragalna’. In both species shading progressively increased F_v/F_m, internal CO₂ concentration, diffusive leaf resistance and specific leaf area (up to 8 %, 34 %, 18 % and 68 %, respectively), and decreased Chl content, T_max, photosynthetic rate and plant dry weight (up to 9 %, 24 %, 79 % and 39 %, respectively). As plants aged, characteristic bell‐shaped trends were evident for photosynthetic parameters, with F_v/F_m increasing up until the onset of flowering, and thereafter declining. This implies that F_v/F_m may be a useful indicator of earliness in subterranean clover genotypes. The aboveground dry biomass response to shading was both genotype‐ and season‐dependent, but was predictable from the measurement of relative leaf Chl content. Moreover, our results suggest that an improvement in the interaction between host‐rhizobium may represent a major potential breeding target for enhancing subterranean clover tolerance to shading.