聚乙烯醇与腺苷三磷酸混合浸种处理对小麦幼苗抗寒性的影响

本文研究了ＰＶＡ＋ＡＴＰ混合浸种处理对小麦幼苗抗寒性的影响。结果表明这一处理能明显增强小麦幼苗抗寒性，其生理生化基础表现为呼吸减弱，束缚水／自由水比值增大，可溶性糖、蛋白质等保护物质积累较多，ＳＯＤ、过氧化氢酶、过氧化物酶等保护酶系统活性提高，自由基清除能力增强，膜脂过氧化水平降低。     

Population viability of the narrow endemic Helianthemum juliae (CISTACEAE) in relation to climate variability

Narrow endemic plants are highly vulnerable to extinction as a result of human disturbance and climate change. We investigated the factors affecting the population viability of Helianthemum juliae, a perennial plant endemic to the Teide National Park on Tenerife, Canary Islands. One population was demographically monitored from 1992 to 2001 and analysed using matrix projection models to determine finite rates of increase and critical stages in the life cycle. Lambda values varied between 0.697 and 1.740, and were highly positively correlated with annual precipitation, but not with temperature. Survival of adults had the highest elasticity, and summed elasticities of the growth and fecundity transitions correlated positively with lambda and precipitation. Most of the mortality in the population seemed drought-related, and no other threats were identified. Deterministic simulations showed population increase, but introducing environmental stochasticity by modelling variation in precipitation from existing data of the past 85 years revealed high extinction probabilities (0.74-0.83 in the next 100 years). This plant is likely to be at risk under scenarios of global warming. Our simulations suggest that augmenting the population would only delay extinction. A more viable option for long-term conservation seems to be the introduction of populations at more humid locations within the Teide caldera.     

纳米SiO2对PVA基复合涂膜包装材料成膜透湿性能的影响

为改善聚乙烯醇（PVA）涂膜的阻湿保鲜效能特性,该文采用添加纳米SiO2对PVA基复合涂膜包装材料进行改性,应用响应曲面方法研究SiO2、硬脂酸、戊二醛对三元复合涂膜材料成膜效能特性的影响及交互作用。结果表明：加入纳米SiO2改性可有效提高PVA基复合涂膜包装材料的阻水、阻湿性能,优化组成膜透湿率8.18 g/(m2·d)比对照组（不添加纳米SiO2的PVA复合膜）降低26.61%（p<0.05）;硬脂酸、戊二醛对复合涂膜材料成膜透湿率的影响与纳米SiO2存在显著的交互作用,每100 mL 0.05 g/mL的PVA溶液中纳米SiO2添加量在小于0.05 g范围内随着SiO2含量增大,复合涂膜材料成膜透湿率随硬脂酸、戊二醛的比例增加而降低,阻湿性能提高。     

聚乙烯醇在枣和酸枣组织培养中的作用

以冬枣、酸枣组培苗为试材,研究了聚乙烯醇不同浓度在冬枣和酸枣组培苗继代增殖中对其玻璃化的影响、在生根培养中对生根效果的影响及在叶片培养中对愈伤组织诱导的影响。结果表明,2.0g/L的聚乙烯醇能够有效降低冬枣和酸枣组培苗在继代增殖中的玻璃化现象,并能提高组培苗在生根培养中的生根条数和根长度;1.0、1.5g/L的聚乙烯醇可使酸枣和冬枣组培苗叶片愈伤组织发生时期提前,并可提高愈伤组织发生率和发生量、改善愈伤组织的质量。因此,聚乙烯醇在冬枣和酸枣的继代增殖、生根培养及叶片愈伤组织诱导中均有良好的促进作用。     

糖皮质激素受体阻断对雏鸡热应激的影响

本研究用５０ｍｇ／ｋｇ体重的Ｒｕ４８６ＰＶＡ缓释剂皮下注射，阻断雏鸡淋巴细胞糖皮质激素受体（ＧＲ），在２４ｈ内受体阻断率达６０％。受体阻断细胞对体内正常量糖皮质激素（ＧＣ）几乎无反应，并且有拮抗外源性ＧＣ的作用。将ＧＲ阻断鸡群置于高温环境（４３℃），结果该鸡群对热刺激耐受性明显提高，表现为热应激５ｈ内存活率提高８０％，平均存活时间延长５２％，血浆ＡＣＴＨ水平及血糖浓度无明显变化     

几种化学药剂对烟草种子萌发的促进效果

本文比较了腺苷三磷酸(ATP)、聚乙二醇(PEG)和聚乙烯醇(PVA)处理烟草种子后种子活力及生理生化的变化,结果表明烟草种子经ATP、PEG和PVA处理后,发芽率和种子活力有所提高,出苗时间缩短,种子浸出液的相对电导率大幅度下降,过氧化物酶、脱氢酶和酸性磷酸酯酶活性均显著提高.其中以4%浓度PVA处理烟草种子3 d,种子活力提高明显;而以20%浓度PEG处理3 d后烟草种子幼苗的整齐程度较好.     

缓释尿素制剂及其蛋白精料的制备与检验——Ⅰ.缓释尿素制剂及其精料的实验室制备与检测

本试验选用PVA及UF、PVFM胶液作包被剂制备缓释尿素制剂,研究其使用方法,用量及其缓释效果。综合包被率、溶解率等检测结果筛选出PVA作包被剂。以此制备缓释尿素蛋白精料,与无包被的尿素蛋白精料进行比较,两者的尿素溶解率存在显著差异（P<0.05）。溶解率的测定方法与恒温水浴脲酶法为体外检测尿素制剂与尿素精料缓释效果的简易方法。     

Long-term dynamics and population viability in one of the last populations of the endangered Spiranthes spiralis (Orchidaceae) in the Netherlands

During the last decades, most orchid species in much of Western Europe have suffered significant declines and the long-term survival of the remaining populations remains to a large extent uncertain. In particular, populations at range margins may be more prone to extinction than more central populations, as the former tend to be small and isolated, occur in ecologically marginal habitats and have a lower per-capita reproductive rate. In this study, we investigated the long-term dynamics and population viability of a population at the margin of its range of Spiranthes spiralis in the Netherlands. At present, only 2 out of 40 previously known populations persist. Individual plants were monitored for 24 years and their life span, flowering frequency and vegetative growth were determined. Individual plants showed large temporal variation in sexual and vegetative growth among years. The proportion of flowering plants varied from 0 (no plants were flowering) to 100 (all plants were flowering). Vegetative growth, on the other hand, increased when the number of individuals decreased. Dormancy was present, but occurred only in a few individuals. Using a non-structured population viability model, future prospects of this species were assessed. Calculation of extinction probabilities and estimated times to extinction using the diffusion approximation model showed that the species had a relatively high probability (79%) of surviving the next 20 years, whereas the median time to extinction was forty years. However, because 95% confidence intervals of the population growth included 1, we suggest that continued monitoring and additional genetic research are needed to assess the long-term viability of this species.     

微生物肥料的包埋固定化研究

为了克服单种材料包埋的不足,提高微生物肥料包埋颗粒的综合性能,本研究以海藻酸钠（SA）配合聚乙烯醇（PVA）为包埋剂,并添加适宜辅料,对复合菌体（根瘤菌解磷菌解钾菌）进行包埋固定化,以包埋操作及颗粒综合性能等为指标,筛选出较优的包埋材料组成为:SA3.0%-PVA（2.5%~3.0%）辅料（SiO24.0%CaCO30.3%）。在此条件下,操作性和成球性较好,所得包埋颗粒呈规则球形,直径为3mm～4mm,机械强度为53.4g/g～59.6g/g,包埋率为91.4%～94.3%,经过72h增殖培养颗粒的活菌数达到1011cfu/g,增殖500多倍,活菌释放率达到90%以上。     

内蒙古赛罕乌拉国家级自然保护区中华斑羚种群生存力分析

【目的】基于种群生存力分析,为孤立种群中华斑羚的物种保护提供依据。【方法】根据赛罕乌拉国家级自然保护区隔离分布的中华斑羚种群连续10年的观察数据,参照种群大小、婚配制度、环境容纳量、遗传多样性、灾害发生的频率等种群参数,并结合斑羚其他种群的研究结果,利用漩涡模型(Vortex 10.2.7.0)进行种群生存力模拟分析。【结果】该种群未来100年的存活率将下降到0.33。新生幼崽性比、新生雌性幼崽死亡率、成年雌性死亡率是影响斑羚种群增长的重要限制因子。如能补充外源个体,即每3年补充1只雌性和1只雄性,该地区斑羚数量能稳定增长,无灭绝风险。【结论】该地区斑羚种群的生存动态不容乐观,补充外源个体是促进种群增长最有效的方法。严寒冬季补充饲料和营养盐,改善个体生存和繁殖条件,也是维持种群稳定的重要措施。