Resource utilization conditions as biochar of an invasive plant Spartina alterniflora in coastal wetlands of China

Converting feedstocks of invasive plants into biochar is a new and cost‐effective measure for their control, and benefits for the sustainable development of native ecosystems. Spartina alterniflora, an invasive plant widely distributed in coastal wetlands of China, was used to produce biochar. We aimed to analyze how S. alterniflora biochar properties changed with desalination of feedstocks, pyrolysis temperature, and residence time. Results showed that desalting feedstocks increased biochar pH, stability, porosity, and surface area, but diminished biochar yield and polarity. Pyrolysis temperature positively affected biochar pH, surface area, and pore volume, while it had negative effects on biochar yield, oxygen and hydrogen contents, hydrogen/carbon and oxygen/carbon ratios, pore size, and function groups. However, residence time of pyrolysis had slight effects on biochar properties. The results are valuable for optimizing pyrolysis temperature and pretreatment measure of feedstocks, to tune S. alterniflora biochar properties for specific environmental usage.     

华南地区22种园林植物耐旱性分级筛选

以华南地区22种常见园林植物为研究对象，研究人工模拟干旱胁迫环境对植物叶片叶绿素、丙二醛、过氧化物酶、相对电导率等生理指标的影响，通过主成分分析、聚类分析对22种植物耐旱性进行综合分析评价和耐旱等级划分。结果表明：(1) 在干旱梯度胁迫期间，植物叶片的叶绿素含量总体上呈不同程度的下降趋势，少数呈上升趋势，丙二醛含量和相对电导率均呈不同程度的上升趋势，多数植物过氧化物酶活性呈不同程度先升后降趋势，少数呈持续上升趋势。(2) 22种植物耐旱性分为3个等级：A级强耐旱植物4种，包括灰莉(Fagraea ceilanica)、鸭脚木(Schefflera octophylla)、桂花(Osmanthus fragrans var. fragrans)、鸢尾(Iris tectorum)；B级中耐旱植物6种，包括翠芦莉(Ruellia simplex)、栀子花(Gardenia jasminoides)、变叶木(Codiaeum variegatum)、红车(Syzygium hancei)、红背桂(Excoecaria cochinchinen)、茉莉花(Jasminum sambac)；C级不耐旱植物12种，包括福建茶(Carmona microphylla)、米仔兰(Aglaia odorata)、大红花(Hibiscus rosa-sinensis)、琴叶珊瑚(Jatropha integerrima)、龙船花(Ixora chinensis)、黄蝉(Allamanda schottii)、假连翘(Duranta erecta)、红檵木(Loropetalum chinense var. rubrum)、紫薇(Lagerstroemia indica)、风车草(Cyperus involucratus)、小花月季(Rosa chinensis var. minim)、铜钱草(Hydrocotyle chinensis)。     

A new species of Callispa Baly (Coleoptera,Chrysomelidae, Cassidinae,Callispini) infesting coconut?palm ( Cocos nucifera L.) in India

Callispa keram sp. n. infesting coconut palm (Cocos nucifera L.) in Kerala, India is described and illustrated. Livistona chinensis R.Br. and Syagrus romanzoffiana (Cham.) Glassman are reported as additional host plants.     

Biological methods for speciation of heavy metals: different approaches

Heavy metals are found in their different forms in the environment. The distribution, mobility, and toxicity of metals are strongly related to these different forms. This necessitates the exploration of different methods for the remediation and speciation of heavy metals. Some direct and indirect physico-chemical methods such as filtration, chemical precipitation, ion-exchange, electro deposition, and membrane systems have been used for the last four decades. However, it is only in last few years that reliable biological methods have also been used. The biological methods include the use of microorganisms (fungi, algae, bacteria), plants (live or dead) and biopolymers. The use of these methods for the speciation of heavy metals is reviewed here.     

Biosynthesis and Genetic Engineering of Lignin

Lignin, a complex heteropolymer of cinnamyl alcohols, is, second to cellulose, the most abundant biopolymer on Earth. Lignification has played a determining role in the adaptation of plants to terrestrial life. As all extracellular polymers, lignin confers rheological properties to plant tissues and participates probably in many other functions in cell and tissue physiology orin cell-to-cell communication. Economically, lignin is very important because it determines wood quality and it affects the pulp and paper-making processes as well as the digestibility of forage crops. For all these reasons the lignin biosynthesis pathway has been the subject of many studies. At present, most genes encoding the enzymes involved in the biosynthesis of lignin have been cloned and characterized. Various recent studies report on the alteration of the expression of these genes by genetic engineering, yielding plants with modified lignin. In addition, several mutants have been analyzed with changes in lignin content or lignin composition resulting in altered properties. Thanks to these studies, progress in the knowledge of the lignin biosynthesis pathway has been obtained. It is now clear that the pathway is more complex than initially thought and there is evidence for alternative pathways. A fine manipulation of the lignin content and/or composition in plants is now achievable and could have important economical and environmental benefits.     

In vitro selection for salt tolerance in crop plants: Theoretical and practical considerations

Summary In recent years attempts have been made to supplement traditional breeding for the production of salt-tolerant plants with variability existing in cell culture. The potential causes suggested as an explanation for the limited success of the in vitro approach include: a) lack, or loss during selection, of regeneration capability; b) the development of epigenetically adapted cells; c) lack of correlation between the mechanisms of tolerance operating in cultured cells and mechanisms that operate in cells in the intact plant; and d) multigenicity of salt tolerance. The recent successful production of healthy, fertile, and genetically stable salt-tolerant regenerants from cells obtained from highly morphogenic explants which are selected early in culture (using one-step or short-term strategies) for salt tolerance, together with the demonstration that salt-sensitive plants can become tolerant by mutations in one or few genes, suggest that some of the potential limitations can be overcome and that some of them may not exist at all.     

Behavioral response of female Helicoverpa armigera (Hübner) to different plant part extracts of African marigold Tagetes erecta (L.)

The flowering stage of African marigold Tagetes erecta (L.) was the most preferred for oviposition by Helicoverpa armigera (Hübner). The lower sides of leaf margins received more eggs compared to buds, stem tip and flowers. Olfactometer studies revealed that more female moths were attracted towards the flower extracts, followed by leaf, bud and stem tip extracts of African marigold. The thin layer chromatography analysis of these extracts showed a blend of compounds including careen, ocimene, methyl benzoate, phenyl acetaldehyde and phenyl ethanol. Attempts have been made to correlate insect behavior with the presence of these compounds.