Phytoaccumulation of iron by callus tissue of Clerodendrum indicum (L)

Clerodendrum indicum (L.) is one of the important medicinal plants, originating in India. The plant is used as medicine for bronchitis, asthma and different immunological disease. Micro-propagation is a quick method, producing a huge number of plants. Apical leaf of Clerodendrum indicum (L.) was used as an explant for callogenesis. The combinations of different plant growth regulators (2,4-D, NAA, KN) in MS (Murashige and Skoog) medium produced two types of calli: one was friable and loose and the other was green, embryogenic and compact. Heavy metals cause pollution and health hazards. The plant absorbs heavy metals, which is very useful for controlling environmental pollution. Iron is a major nutrient for both plants and animals, but hyper accumulation of iron is injurious to health. Calli were used to study the optimum conditions of iron uptake in presence of different chemical environments. The different environments were created by using different chemical reagents such as (HCL, HNO₃, H₃PO₄ and KNO₃). Iron (III) was spiked with radioactive Fe-59 and dynamics of uptake was followed by measuring radioactivity by gamma-ray spectrometer. The best condition of iron uptake corresponded to 1 mol L^?1 KNO₃ after 4 hour of equilibration.     

Physiological,biochemical and growth responses of Azolla pinnata to chlorpyrifos and cypermethrin pesticides exposure: a comparative study

Cypermethrin and chlorpyrifos pesticide- (5, 15 and 30 ppm) induced effects on growth, metabolic and antioxidative behaviour of Azolla pinnata were analysed after 96 h of treatment. Growth of A. pinnata was increased by 72–76% over the initial mass under control condition. Further, the growth was decreased by 26 and 30% following treatment with 5 ppm of cypermethrin and chlorpyrifos, respectively, compared to control. Whereas, 30 ppm of pesticide treatment caused substantial decrease in biomass accumulation, even less than the initial mass. The Chlorophyll a content was declined at higher concentrations of chlorpyrifos, while carotenoids content increased significantly in the presence of both the pesticides. Photosynthetic rate showed declining trend with rising concentration of pesticides, while an increasing trend was noticed in the case of respiratory O₂ consumption. The oxidative biomarkers malondialdehyde, superoxide radicals and hydrogen peroxide increased with increasing concentration of both the pesticides. The activity of enzymatic antioxidants enzyme superoxide dismutase, glutathione-S-transferase and ascorbate peroxidase (APX) was enhanced with increasing concentrations of both the pesticides; however, a declining trend was noticed in the case of APX at 30 ppm chlorpyrifos treatment. The study concludes that chlorpyrifos appeared to be more toxic than cypermethrin; however, both the pesticides significantly reduced the growth performance.     

Metabolic responses of Azolla pinnata to cadmium stress: photosynthesis,antioxidative system and phytoremediation

This present study deals with the growth, photosynthesis, oxidative stress and phytoremediation character of Azolla pinnata L. exposed to different levels (0.05, 0.1, 0.5, 1.0, 1.5 and 2.0 mg·L^?1) of cadmium (Cd). Significant accumulation of Cd in Azolla fronds was noticed after 24 and 96 h of exposure and the accumulation rate was dose and time dependent. Growth of A. pinnata increased significantly after both exposure times with and without metal. At lower Cd doses (0.05 and 0.1 mg·L^?1), growth and photosynthesis of A. pinnata showed a marginal increase over the respective control, however, at higher Cd doses (0.5, 1.0, 1.5 and 2.0 mg·L^?1), a decreasing trend was noticed. At lower doses, Azolla fronds could counterbalance the negative effect of enhanced levels of superoxide radicals (SOR) and hydrogen peroxide (H₂O₂) through the greater activity of antioxidative enzymes. The decaresing trends in catalase and peroxidase activity at higher Cd doses suggest that Azolla fronds were not able to mitigate the negative effects of H₂O₂, hence an increase in malondialdehyde content was noticed. The study concludes that up to 0.1 ,mg·L^?1 Cd, A. pinnata can flourish and be used as biofertiliser and for phytoremedial purposes in Cd-contaminated fields; beyond this concentration poor growth may restrict its application.     

The boll weevil‐cotton plant complex

The boll weevil, Anthonomus grandis Boheman was introduced from Mexico into the United States about 1892. More than three‐fourths of all insect losses to cotton in this country have been attributed to this insect, and it is generally agreed that cotton cannot be profitably grown in areas where it occurs without adequate control measures. This review summarizes the chemically oriented research conducted on this plant‐insect complex during the past seventy years with emphasis on the program conducted since 1962 at the Boll Weevil Research Laboratory.

Of plant‐insect relationships, host plant resistance, feeding stimulants, plant attractants, and plant constituents are discussed. Insect‐insect relationships treated include insecticides, chemosterilants and hormones, sex attractants, and insect constituents. The development of an integrated program for the attempted eradication of this insect is also discussed.     

Effect of Cd++ on germination,growth and active principles of Datura metel L.∗

The effects of Cd⁺⁺ concentration increment in soil and/or in atmosphere, on germination, growth and alkaloid contents of Datura metel L. were investigated. We observed a significant reduction of growth following addition of Cd⁺⁺ in soil. Minor effects on growth were evident when the plants were sprayed with CdCl₂ solution (10mgCd⁺⁺/l).

Scanning electron microscope observation showed stomata widely open and conspicuous cuticular striations in the foliar epidermis of polluted plants.

GLC analysis of extracts evidenced a significant variation in active principle content among plants undergoing different treatments.     

Materialphilia,biophilia, and sustainable use of the planet

SUMMARY

The intricate and complex relationships between transhumant pastoralists, livestock and environment at the high altitudes of Indian Central Himalaya has started to break down at an alarming rate. Some of the important factors attributed to this are depletion of grazing resources, commercialization of the rural economy, and integration of these communities with the mainstream of development through education and employment. Traditionally these livestock were assigned different roles in society depending upon their economic benefit and utility. The roles which once depended upon attitude to various risks, such as environmental, social and economic, have lost their significance due to changing of the production process. This paper gives an overview of the various types of roles the livestock played in the transhumant society, and how they are being replaced by the developmental process in the region, and whether the changes are sustainable for such remote regions in a developing country.     

不同密度水浮莲的形态和生长反应及其对土壤养分的影响

为了解入侵植物水浮莲在水生环境中的入侵和扩散规律,本文通过田间水稻田实验,按照添加系列设计方法研究不同密度下水浮莲幼苗的形态和生长反应,以及对土壤养分的影响。结果表明,不同种植密度下水浮莲在母株株高、母株叶片数、分蘖能力、开花株数和死亡株数生长动态具有明显的差异。水浮莲形态特征,随种植密度降低分蘖等级和数量显著增加,密度60株时最大为29.45株·基株-1,360株时最小为1.10株·基株-1;母株株高总体上呈现出逐渐降低的趋势,而根长的变化规律不明显;中等种植密度的母株叶片数明显大于低等和高等密度的;植株开花与死亡株数多数显著增加;水浮莲出现有性和无性繁殖,但无性繁殖占绝对优势。水浮莲生物量,随种植密度降低总生物量显著增加,60株时最大为31.18 g·基株-1,360株时最小为5.64 g·基株-1;母株生物量总、花、叶和根生物量总体上逐渐降低,而分蘖植株总、叶、花和根生物量显著增加。水浮莲生长需要消耗大量的土壤养分,其中对有机质和速效钾消耗是最大的,分别达到8.55~21.56 g·kg-1和649.43~679.45 mg·kg-1;随种植密度降低水浮莲对土壤有机质、氮、磷和钾的吸收绝大多数显著增加。不同种植密度下水浮莲在形态、生长、繁殖以及对土壤养分影响的差异,可能是由其最初种植密度形成不同的种内竞争强度造成的。     

干湿交替对福寿螺摄食和生长的影响

福寿螺（Pomacea canaliculata）被世界自然保护联盟列入世界100种恶性外来入侵物种黑名单,在我国南方已对水稻生产造成严重危害。为了探索通过水分调控来防治福寿螺的方法,本研究模拟福寿螺野外生存条件,探讨不同干湿交替条件下福寿螺摄食和生长的情况,来分析干旱胁迫对其体重增长率(Weight growth rate,WGR)、摄食率（Feeding rate,FR）、食物转化率(Food conversion ratio,FCR)、特定生长率（Specific growth rate,SGR）等的影响。结果表明：福寿螺在干湿交替条件下,其WGR、FR、FCR、SGR均受到明显抑制,甚至出现负值的情况;福寿螺的壳高随着有水时长的延长而增加,出现干旱时间越长,壳高增长越缓慢的现象;福寿螺在短时期干湿交替条件下发生部分补偿生长现象,这种补偿生长效应可能主要是通过饥饿后摄食水平提高而实现的,但超出一定限度时则不能补偿生长。根据上述结果,可以认为福寿螺在缺水条件下无法正常生长,且影响程度随着干旱时间的增加而增大。此外,福寿螺普遍会在旱后复水180min内钻出土壤,因此,可利用此时机防治福寿螺,及时避免其损伤水生作物。本研究结果可为稻田福寿螺的综合防治和水资源利用管理提供理论参考。     

Challenges for a sustainable resource use: Uncertainty,trade, and climate policies

We integrate new challenges to thinking about resource markets and sustainable resource use policies in a general framework. The challenges, emerging from six papers that JEEM publishes in a special issue, are (i) demand uncertainty and stockpiling, (ii) international trade and resource dependence, (iii) deforestation, and (iv) intertemporal effects of climate change policies (“Green Paradox”). We discuss new insights and results on these issues by fitting them into the Hotelling model of non-renewable resource depletion.