河北省1997—2007年生态足迹及生态承载力变化分析

应用生态足迹模型,利用相关统计数据对1997—2007年河北省的生态足迹及相关指标进行了计算和分析,对河北省的可持续发展进行定量分析。计算结果显示,河北省的生态经济发展状况非常严峻,河北省的生态赤字很高,生态足迹多样性很低,河北省的生态经济系统中生态空间的分配很不均等,在河北省的生态足迹中,能源足迹占比很大,说明河北省产业结构属于高能源消费型。在此基础上,找出河北省可持续发展的主要影响因素,提出河北省可持续发展的应对策略。     

2007—2009年荆门市肥料质量监测研究

通过对荆门市农资市场肥料连续3年的定向监测,发现肥料3年抽检平均合格率为62.6%,2009年为64.9%。复混(合)肥料3年抽检平均合格率为67.3%,其中高浓度复混肥料质量良好,3年抽检平均合格率为87.2%;过磷酸钙3年抽检平均合格率为61.9%;硼肥质量较差,3年抽检平均合格率为51.3%。并据此提出了改进对策。     

Fungal endophytes reduce regrowth and affect competitiveness of meadow fescue in early succession of pastures

Systemic‐ and seed‐transmitted fungal endophytes are suggested to enhance competitive dominance of agronomic grasses by increasing plant growth and defence against herbivores. We studied whether Neotyphodium uncinatum endophyte infection frequencies of meadow fescue (Schedonorus pratensis) and botanical composition of pastures are affected by 4, 5, 7 and 21 years of grazing by dairy cattle. We then examined with one greenhouse and two field experiments, whether endophyte infection and clipping affect regrowth of young or mature plants relative to nutrient availability in soil. The frequencies of infected plants and the number of plant species were less in grazed parts of the pastures. Endophytes significantly reduced relative regrowth and dry biomass of regrowth of the grass irrespective of nutrient levels in a 1‐year‐old field (on an average 18% in 2 months) and under high nutrient conditions in the greenhouse experiment (on an average 3% in 3 months) respectively. However, effects of endophytes were not detected in 5‐year‐old fields and under low nutrient conditions in the greenhouse. In contrast to past studies, our results demonstrate that grazing may negatively affect endophyte–grass symbiosis and number of plant species of successional pastures, and suggest that the effects of endophytes may be linked to the ontogeny of the host.     

披碱草内生真菌对三种草坪草种子与种苗的化感效应

以多年生黑麦草、高羊茅和草地早熟禾3种草坪草作为供试对象,用种子萌发法和盆栽法初步测定了披碱草内生真菌的化感效应。结果表明,披碱草内生真菌对3种草坪草种子萌发与生长具有一定的影响作用。种子室内滤纸萌发条件下,披碱草草粉对3种草坪草种子萌发有一定的抑制作用;且内生真菌显著增强了披碱草草粉对多年生黑麦草苗重、对高羊茅的发芽率、根长、苗长、苗重和对草地早熟禾发芽率的抑制作用(P<0.05),显著降低了披碱草草粉对多年生黑麦草的根长和苗长、对高羊茅的根重以及对草地早熟禾根长的抑制作用(P<0.05)。盆栽条件下,披碱草草粉对3种草坪草的生长均有一定的促进作用;且内生真菌显著增强了披碱草草粉对高羊茅初期发芽率的促进作用(P<0.05),显著降低了披碱草草粉对多年生黑麦草的初期发芽率和对草地早熟禾苗长的促进作用(P<0.05)。     

石河子市园林植物种类及秋季色彩调查研究

对石河子市的校园绿地、宾馆绿地、道路绿地、小区绿地、广场绿地的园林植物种类及秋季色彩进行了调查与分析。结果表明:调查样地中园林植物共计45种,隶属16科30属45种;植物秋季色彩比例不协调,其中黄色系植物占比最大,为68.89%;紫色系和红色系植物仅占6.67%和11.11%。通过Q型聚类分析,调查的灌木和乔木分别聚为3个类群,并提取每类群的共同特征。在研究的基础上,为石河子市营造色彩丰富的秋季景观效果提出了合理改进的建议。     

A simultaneous effect of selfing and Epichloë endophyte on forage,seed yield and turf characteristics of perennial ryegrass (Lolium perenne L.)

Ryegrass (Lolium perenne L.) is a putative turf and forage plant characterized as mainly outcrossing in which the extent of self‐fertilization and its consequences has not been investigated. In this study, selfed and half‐sib family seeds were obtained from ten clonally propagated ryegrass plants among which two were endophyte‐free (EF) and eight were endophyte‐infected (EI). Then, 20 seed populations plus two commercial varieties of Speedy and Vigor were sown and evaluated in a biennial experiment for their turf and forage characteristics. Selfing caused significant inbreeding depression for plant fresh and dry weight and leaf length and width in the first year for both EI and EF genotypes. In the second year, only leaf length remained depressed among these characters. Also, for the most growth, turf and reproductive traits, EI populations showed less depression. The presence of endophyte in self‐pollinated populations made an increasing effect for the number of seed per spike and days to heading, although seed weight was reduced. Some of the populations derived from self‐pollination and infected with fungal endophyte including S9 and S10 were even superior to the two commercial varieties in terms of both seed production and turf characteristics. However, for seed‐related characteristics including number of spikes per plant, seed weight and seed yield, EF populations including Speedy and Vigor were more reproductive than EI populations. It is concluded that selfing may increase the discrimination between EI and EF ryegrass plants because endophyte infection may mitigate the negative consequences of inbreeding depression in prone populations.     

产萱草根素内生真菌的分离与鉴定

为探讨萱草(Hemerocallis)根中是否存在产生萱草根素的内生真菌,从北萱草(H.esculenta)根中分离得到4株内生真菌,在马铃薯(Solanum tuberosum)葡萄糖琼脂培养基(PDA)上培养20 d后收集菌丝,应用薄层色谱法和紫外分光光度法分别检测菌丝提取液中的萱草根素,筛选可产生萱草根素的内生真菌。结果表明:菌株XC-1A为产萱草根素内生真菌,含量达359.88 μg·g^-1,根据形态学观察和5.8S rDNA-ITS序列分析结果,确定XC-1A为Zalerion varium。北萱草中存在可产生萱草根素的内生真菌。     

灌水对不同小麦品种耗水特性和土壤硝态氮运移的影响

为了解灌水对不同小麦品种耗水特性和土壤硝态氮运移的影响,在大田条件下,以济麦20和泰山22为材料,设置4种水分处理[W0处理（全生育期不灌水）、W1处理（灌底墒水＋拔节水）、W2处理（灌底墒水＋拔节水＋开花水）、W3（灌底墒水＋拔节水＋开花水＋灌浆水）],每次灌水量60mm,分析了不同灌水处理下小麦0～200cm土层土壤含水量、土壤水消耗量、土壤硝态氮运移及籽粒产量的差异。结果表明,（1）依据土壤含水量受灌水影响的程度和变异系数,将0～200cm土壤分为3个层次：活跃层（0～60cm）、次活跃层（60～140cm）和相对稳定层（140～200cm）。（2）两品种W1处理的冬前、开花和成熟期0～60cm土层土壤硝态氮含量低于W0处理;冬前期60～140cm土层高于W0处理,140～200cm土层与W0处理无显著差异;开花期60～140cm和140～200cm土层高于W0处理;成熟期0～60cm土层高于W2、W3处理,60～140cm和140～200cm土层低于W3处理。拔节期济麦20W1处理60～140cm和140～200cm土层土壤硝态氮含量高于W0处理,泰山22的低于W0处理。（3）济麦20各处理0～200cm土层土壤水消耗量均高于泰山22。济麦20W1处理0～60cm和60～140cm土层土壤水消耗量高于W2处理,籽粒产量、水分利用效率高于W2、W3处理;泰山22W2处理0～60cm土层的土壤水消耗量与W1处理无显著差异,60～140cm和140～200cm土层的土壤水消耗量低于W1处理,水分利用效率与W1处理无显著差异,但高于W3处理,籽粒产量高于W1、W3处理。济麦20和泰山22分别以底墒水、拔节水各灌60mm和底墒水、拔节水、开花水各灌60mm为节水、高产、氮素淋溶量低的最佳灌水模式。     

醉马草内生真菌对家兔的影响

通过饲喂试验,研究了带内生真菌(E+)和不带内生真菌(E-)的醉马草对家兔健康的影响。内生真菌的侵 染,使醉马草粗脂肪含量显著提高,粗蛋白和粗纤维含量无显著改变。按10 mL/kg体重的剂量灌服E+醉 马草水提液,家兔表现出明显的中毒症状;但累计灌服20 mL/kg体重的剂量,亦未引致死亡。平均按每 kg体重累计饲喂E+醉马草131.6 g,可引起家兔中毒;累计饲喂350.9 g可使家兔致死,死亡率达66.7%。 而灌服和饲喂E-醉马草的家兔则无异常。初步认为,醉马草对家兔的致毒机理是由内生真菌与宿主互作 产生的生物碱所致。     

禾本科植物内生真菌研究3:产生子座而无有性孢子的Neotyphodium属内生真菌-拂子茅属植物新共生体

2006年5月在南京市南郊发现了着生内生真菌子座的禾本科植物。子座长47.5~165.0mm,白色,包裹其宿主植物的旗叶叶鞘;于4月下旬形成,7月中旬完全崩溃;在自然条件下、人工交配试验中,子座上均未形成有性生殖结构。宿主植物直立,高90~120cm,有丰富的根状茎;连续2个花期均无抽穗。根据植物外部特征、叶表皮微形态特征以及rDNA-ITS序列的分析结果,将这种不抽穗的禾本科植物鉴定为拂子茅属植物(Calamagrostis sp.)。从29株着生子座的植株和87株不着生子座的植株中全部检出了内生真菌,从中分离得到了20个菌株。根据分生孢子、分生孢子梗的形态特征,分离菌株被鉴定为Neotyphodium属内生真菌。宿主植物的特殊性和菌株的子座形成能力显示了这是一个禾本科植物-内生真菌的新组合。这个组合是产生子座而不形成有性世代的第3例,并且这3例组合的宿主都是翦股颖族植物。