二色补血草试管苗生根及移栽基质研究

以二色补血草为材料,研究了不同浓度激素配比对试管苗生根量及根长的影响,以及生根苗在不同移栽基质中的成活率和生长状况。结果表明,试管苗在MS+NAA 1.0mg/L培养基中的平均根量最多,在MS+IBA 1.0mg/L培养基中平均根长最长;生根苗在泥炭+珍珠岩(1:1)的基质中生长最好。同时进行降低成本的试验。     

Responses of a beaded Arctic stream to short-term N and P fertilisation

1. Oligotrophic Arctic streams are likely to be sensitive to changes in hydrology and nutrient inputs predicted to occur as a consequence of future climate and land use change. To investigate the potential consequences of nutrient enrichment for low‐order Arctic streams, we added ammonium‐N and phosphorous to a second‐order beaded, tundra stream on Alaska's north slope. We measured responses in nutrient chemistry, chlorophyll a standing crop, and in the breakdown and macroinvertebrate colonisation of leaf litter over a 38‐day summer period. 2. During the addition, nutrient concentrations immediately downstream of the dripper averaged 6.4 μm ammonium‐N and 0.45 μm soluble reactive P. Concentrations upstream of the dripper averaged 0.54 μm ammonium‐N and 0.03 μm soluble reactive P. Uptake of both nutrients was rapid. Concentrations were reduced on average to 28% (ammonium‐N) and 15% (inorganic P) of maximum values within 1500 m. Standing crops of chlorophyll a on standardised samplers were significantly higher by the end of the experiment. Breakdown rates of senescent willow (Salix sp.) and sedge (Carex sp.) litter and associated fungal biomass were also significantly increased by nutrient addition. 3. Fertilisation resulted in four‐ to sevenfold higher macroinvertebrate abundance and two‐ to fourfold higher macroinvertebrate biomass in litter bags, as well as an increase in late‐summer body mass of larval Nemoura stoneflies. 4. Our results are consistent with those of similar studies of larger streams in the high‐Arctic region. Based on our short‐term experiment, increased inputs of nutrients into these ecosystems, whether caused by climate change or more local disturbance, are likely to have profound ecological consequences. Longer‐term effects of enrichment, and their interaction with other components of future change in climate or land use, are more difficult to assess.     

A common‐sense approach to tropical peat swamp forest restoration in Southeast Asia

Tropical peat swamp forests (TPSFs) are found mainly in Southeast Asia and especially Indonesia. A total of 61% were lost between 1990 and 2015 and 6% remained in a pristine condition by 2015. Tropical peat swamps store vast amounts of carbon in their peat, but peat degradation, through drainage and fire, leads to high greenhouse gas emissions. This is gaining much international attention and, with it, policy initiatives and funding for restoration from local to landscape scales are being promoted. Unfortunately, although there is a now strong desire and need for TPSF restoration, methods are lacking. Ecological understanding is still at an early stage, and, even more so, in its applied use. There is an imbalance between the activities of TPSF restoration and sound ecological application. Furthermore, while many activities are underway and knowledge is being gained, these techniques are yet to be published. This article has been written to provide a common‐sense, practical guide to tropical peatland forest restoration which summarizes what we know to date, while acknowledging the gaps in our understanding. Topics covered include species selection, land assessment, land selection, and appropriate nursery, transplanting, and monitoring methods. The authors make no apologies that in places this reads like a manual as, given the importance of tropical peatland recovery and the recent attention and funding opportunities available, it is essential we now provide techniques to restoration practitioners working on the ground, and a basic common‐sense approach must be the starting point.     

南高丛蓝莓‘奥尼尔'工厂化组培快繁技术研究

为了建立南高丛蓝莓‘奥尼尔’工厂化组培快繁技术体系,该文以带腋芽的茎段为外植体,研究外植体灭菌、丛生芽诱导、丛生芽增殖培养、瓶内生根以及移栽驯化。结果表明：（1）外植体最佳灭菌方法为10%NaClO处理15 min,污染率降低至14.44%,诱导率达49.38%;同样添加1.5 mg·L^-1ZT,以WPM为基础培养基诱导出的丛生芽明显多于MS。（2）丛生芽增殖的最佳培养基为WPM+NAA 0.1 mg·L^-1 +ZT 1.5 mg·L^-1 ,接种60 d后增殖系数达8.6,长势良好;瓶内生根的最佳处理方式为先用500 mg·L^-1 IBA浸蘸20 s,然后接种于WPM+IBA 0.2 mg·L^-1的生根培养基中,培养90 d后,生根率、有效生根率、生根数量和根长分别达到96.3%、96.3%、12.7条和43.3 mm,且根系较发达、粗壮。（3）生根苗在移栽基质Ⅰ（河沙∶蛭石∶珍珠岩=1∶1∶1）的移栽成活率最高,达92.22%。以上说明,外植体经10%NaClO处理15 mi...     

Experimental assessment of biotic and abiotic filters driving community composition

Species occurrence in a site can be limited by both the abiotic environment and biotic interactions. These two factors operate in concert, but their relative importance is often unclear. By experimentally introducing seeds or plants into competition‐free gaps or into the intact vegetation, we can disentangle the biotic and abiotic effects on plant establishment. We established a seed‐sowing/transplant experiment in three different meadows. Species were introduced, as seeds and pregrown transplants, into competition‐free gaps and the intact vegetation. They included 12 resident plants from the locality and 18 species typical for different habitats. Last two years, gaps were overgrown with vegetation from surrounding plants and we observed the competitive exclusion of our focal plants. We compared plant survival with the expected occurrence in target locality (Beals index). Many of the species with habitat preferences different from our localities were able to successfully establish from seeds and grow in the focal habitat if competition was removed. They included species typical for much drier conditions. These species were thus not limited by the abiotic conditions, but by competition. Pregrown transplants were less sensitive to competition, when compared to seedlings germinated from seeds. Beals index significantly predicted both species success in gaps and the ability to withstand competition. Survival in a community is dependent on the adaptation to both the abiotic environment and biotic interactions. Statistically significant correlation coefficients of the ratio of seedling survival in vegetation and gaps with Beals index suggest the importance of biotic interactions as a determinant of plant community composition. To disentangle the importance of abiotic and biotic effect on plant establishment, it is important to distinguish between species pool as a set of species typically found in given community type (determined by Beals index) and a set of species for which the abiotic conditions are suitable.     

Evaluating Methods for Transplanting Endangered Elkhorn Corals in the Virgin Islands

Restoration of rare corals is desirable and restoration projects are fairly common, but scientific evaluation of this approach is limited. We tested several techniques for transplant and restabilization of Acropora palmata (the elkhorn coral), an ecologically important Caribbean coral whose populations have suffered severe declines. In rough weather, fragments break‐off colonies of branching corals like A. palmata as a normal form of asexual reproduction. We transplanted naturally produced coral fragments from remnant populations to nearby restoration sites. Untouched control fragments at the donor site died faster and grew slower than fragments attached to the reef, so attaching fragments to the reef is beneficial. Transplanted fragments grew and died at a rate similar to fragments left at the donor site (both groups were attached to the reef), so there were no effects of moving fragments or differences in habitat quality between donor and restoration sites. Growth and survival were similar using four methods of attaching fragments to the reef: cable ties, two types of epoxy resin, and hydrostatic cement. Corals sometimes compete with the macroalgae that dominate degraded reefs, and clearing surrounding algae improved the growth of fragments. After 4 years, transplanted fragments grew to 1,450 cm² in area and so were potentially sexually active. Because the methods tested are simple and cheap, they could be used by volunteer recreational divers to restore locally extirpated A. palmata populations or to enhance reefs where natural recovery is slow.     

Modelling seagrass growth and development to evaluate transplanting strategies for restoration

Background and Aims

Seagrasses are important marine plants that are under threat globally. Restoration by transplanting vegetative fragments or seedlings into areas where seagrasses have been lost is possible, but long-term trial data are limited. The goal of this study is to use available short-term data to predict long-term outcomes of transplanting seagrass.

Methods

A functional–structural plant model of seagrass growth that integrates data collected from short-term trials and experiments is presented. The model was parameterized for the species Posidonia australis, a limited validation of the model against independent data and a sensitivity analysis were conducted and the model was used to conduct a preliminary evaluation of different transplanting strategies.

Key Results

The limited validation was successful, and reasonable long-term outcomes could be predicted, based only on short-term data.

Conclusions

This approach for modelling seagrass growth and development enables long-term predictions of the outcomes to be made from different strategies for transplanting seagrass, even when empirical long-term data are difficult or impossible to collect. More validation is required to improve confidence in the model''s predictions, and inclusion of more mechanism will extend the model''s usefulness. Marine restoration represents a novel application of functional–structural plant modelling.     

脊髓损伤治疗中的细胞移植策略及预处理研究进展

急性脊髓损伤是骨科常见的严重疾患,伤后神经功能恢复及重建是近年来研究的热点,其中细胞移植的研究得到广泛的关注并取得较大的研究进展。本文介绍了细胞移植治疗脊髓损伤治疗的研究现状,其中对移植细胞的来源,移植的时机,移植的途径以及细胞移植存活的问题及应对策略做了重点阐述。同时对增加移植细胞存活率的预处理方法做了简要综述。     

魔芋试管苗移栽死苗原因分析及防治技术研究

分析了魔芋试管苗移栽过程中死苗的原因,主要是由没有经过药剂消毒所致。研究了农用链霉素、多菌灵等农药对试管苗的消毒效果,结果表明:单一药剂处理以农用链霉素效果最好,25 d之内发病率为0,30 d内发病率低于5%;其次是多菌灵,15 d之内发病率低于5%,30之内低于15%;冠菌清有一定的效果,但在30 d之内发病率达到了29.2%;威尔达甲托和百菌清单独使用对试管苗病害的发生没有效果,比不用药剂处理发病率更高;综合药剂处理以百菌清+农用链霉素和冠菌清+农用链霉素效果最好,30 d之内发病率均低于5%;多菌灵+威尔达甲托很差,仅比对照低24.6%,30 d之内发病率达到了56.2%。     

珠美海棠试管苗的土壤支撑生根培养和带坨移栽

以粘壤土做培养基支撑物,选用只含有0．5mg·L^-1IBA和15g·L^-1蔗糖的液体培养基,珠关海棠试管苗茎段生根培养的结果显示,试管苗生根率可达到100．0％,明显高于琼脂支撑培养,根长也显著提高,并且长出正常的根毛。土支撑培养生根的珠美海棠试管苗开瓶炼苗21d后带坨移入营养钵中,移栽后不喷雾、并毋需覆盖塑膜、午后空气相对湿度控制在50％-65％,其成活率达到92．2％;在开瓶炼苗21d后,黑暗中叶片气孔的关闭率从26．7％增加到88．5％。