Volume 17, Issue 4, 2017 September-December

Volume 17, No 4 Pages:
2017 September-December Articles: 9

Edible mushrooms of Mizoram

Twenty-seven (27) species of edible mushrooms growing in both soil and wood have been described here from Mizoram, India. All the species were identified based on their morphological, both macro- and microscopic characteristics. The study was carried out during July 2013 to October 2016. Wood inhabiting fungi viz. Schizophyllum commune (pasi), Lentinula lateritia (pa pal), Auricularia auricular-judae (Pu Vana beng), Lentinus tigrinus (pa hnahkhar), L. polychrous (pa chang/pa puanveng) and soil growing fungi viz., Lactifluus corrugis (pa uithin), Lactarius piperatus (pa lengvar), Macrolepiota dolichaula (pa se-ek), Russula subfragiliformis (pa lengsen), Termotomyces heimii (pa sawntlung), Volvariella taylorii (changel pa) are the edible species known to the local community. Other edible species yet unknown to the local community in Mizoram are also recorded viz., Cantharellus cibarius, Craterellus cornucopioides, Lycoperdon perlatum, Macrolepiota procera, Ramariopsis kunzei, Russula aurora, R. compacta, R. cyanoxantha, Lentinula edodes, Lentinus sajor-caju, Pleurotus ostreatus, P. djamor, Tremella fuciformis, T. mesenterica, Laetiporus suphureus and Fistulina hepatica.

Asymmetric Michael addition using sugar derived organocatalysts

Sugars are low-molecular-weight carbohydrates which consist of polyhydroxyl and carbonyl (aldehyde or ketone) functional groups. Different types of compounds derived from sugars have been used extensively as powerful and effective catalysts for asymmetric synthesis. They are readily available at a reasonable price, easily prepared, no metal contamination and are inert towards moisture and air. They are highly functionalized and have well defined stereogenic centres. Most of them are employed as chiral ligands in metal based asymmetric catalysis and are used for various asymmetric transformations. Different compounds derived from sugars have also been used recently as organocatalysts for asymmetric synthesis. The present article provides some of the organocatalysts used for asymmetric synthesis.

Determination of heavy metals and pesticide residues level in selected sundried and smoked vegetables from Aizawl market

Sundried and smoked vegetables constitute major parts of the Mizo cuisine. Heavy metals and pesticides can be present in vegetables and cause many diseases including cancer. The objective of this study is to determine the concentration of heavy metal and pesticide residues in commonly consumed sundried and smoked vegetables from Aizawl market. Since cancer is prevailing at a high rate in Mizoram, it also aims to study whether there is any link between cancer and these vegetables. The concentrations of heavy metals were analyzed using atomic absorption spectroscopy and pesticide residues levels were analyzed using gas chromatography. This study reveals that the levels of heavy metals tested were within the permissible limits in all the vegetable samples, except for cadmium. Since cadmium exceeds the permissible limit, it can pose health risk for the consumers. The pesticide residues found in the tested samples were all within permissible limits. However, the amount and duration of consumption need to be considered as this can be a predisposing factor for cancer and other diseases.

Morphotectonic and sedimentological aspects in describing the relationship with ancient failure surfaces in southern part of Aizawl anticline, Mizoram, India

Population growth in Aizawl city has caused urban areas to expand into landslide-prone areas. These areas comprised of Bhuban Formation rocks of Surma Group and have geological features that frequently generate ground instabilities. The present study integrated with morphotectonic analysis, geotectonic characterization, role of litho-units including their sedimentological aspects and analyses of precipitation time series reveals that the southern part of Aizawl city is tectonically active and lithologically vulnerable towards landslide disaster. Greater surface slope and similar bed attitude enhance the risk of failure. The massive sandstone overlies upon weak clay surfaces that are regularly lubricated by high down pour. Even moderate rainfall can trigger the landslides. The clay layers can mobilize the geological litho-sequences as a combined result of the tropical humid climate and observed weak slope stability conditions. A catastrophic landslide had killed more than 80 people and many other sliding events have been recorded in adjacent areas. Therefore, this study presents tectonic and geologic conditions which can help to predict future slides.

Standardization of drying techniques for hybrid tea rose variety, Valencia

The present experiment was carried out to standardize suitable drying techniques for hybrid tea rose variety ‘Valencia”. Two types of desiccants viz., silica gel and boric acid were used as embedding materials for drying, and the flowers were dried in hot air oven with different temperature and time combinations such as 40°C for 24 hours and 48 hours, 45°C for 24 hours and 48 hours, 50°C for 24 hours and 48 hours, 55°C for 24 hours and 48 hours, 60°C for 24 hours and 48 hours. Different observations were taken such as fresh and dry weight of flowers and hence moisture loss percentage calculated, petal diameter before and after drying were taken and hence petal shrinkage was determined. Sensory evaluations such as flower colour, shape, texture and overall acceptability was also determined. Results show that maximum moisture loss percentage (86.44%) was obtained in flowers embedded with silica gel and dried at 60°C for 48 hours; largest difference between petal diameter of fresh and dry flowers, and also maximum petal shrinkage of 14.27% occurred in those embedded with silica gel and dried at 60°C for 48 hours, whereas best score in sensory evaluations in terms of flower colour, flower shape, flower texture and overall acceptability were obtained with rose flowers embedded in silica gel and drying at 50°C for 48 hours.

Phenotypic plasticity and ecology of three species of Podostemaceae Rich. Ex C. Agardh

The members of Podostemaceae, commonly called river-weeds, are with very peculiar vegetative form; revealing many unique morphological, anatomical and ecological characters from other angiosperms. They undergo an annual cycle of colonization, establishment of a canopy of mature plant, and dies back when the water level drops. The annual pattern is dictated by high and low water periods. Physico-chemical analysis showed that the largest population of the species occupied an area of full sunlight. Water samples from the two study sites viz. Janiaw and Umtienger localities, both from East Khasi Hills District, Meghalaya, India, showing high pH indicated less human activities of different kind. It is also determined that the species inhabits clean rivers, thus, they serve as an indicator of clean water. They occur primarily in low nutrient condition. Further, it was also observed that dissolved oxygen is the most essential factor for successful establishment of these plants, rather than other nutrients and pH. Toxic discharge of effluents from industries and agrochemical residues are serious threat to podostemads that has unique ecological requirement.

Effect of coal mining on soil physico-chemical properties of Nokrek Biosphere Reserve of Meghalaya, northeastern India

Mining causes massive damage to landscape and biological components of an ecosystem. Due to extensive and unmanaged coal mining in the southern part of Nokrek Biosphere Reserve of Meghalaya, the area has been turned into degraded land since nutrient deficient sandy spoils are hostile for the growth and regeneration of plant communities. Soil is sandy to sandy loam and red, brown to dark brown in colour. The physico-chemical properties of the soil were greatly affected due to coal mining. There is an increased acidity i.e. from 6.00 in the undisturbed forest (control site) to 3.50 in the coal mine spoil since abandoned mine spoil discharge acidic water that are enriched with iron and other metals and metalloids. Apart from this, soil nutrients are greatly depleted. The core zone soils are rich in organic matter and nutrients whereas coalmine spoils show sign of degradation especially in the nutrient content.

A preliminary assessment on the plankton diversity of Serlui ‘B’ dam in Mizoram, northeast India

Planktonic sampling was carried out at Serlui ‘B’ dam, Mizoram, northeast India from July 2016 to April 2017. The present study reported the occurrence of 6 groups of phytoplankton belonging to 27 genera and 16 orders and 4 groups of zooplanktons belonging to 12 genera 7 orders. The phytoplankton group consisted of Cyanophyceae, Bacillariophyceae, Ulvophyceae, Zygnematophyceae, Chlorophyceae and Xanthophyceae. Cyanophyceae were the predominant component of phytoplankton in Serlui ‘B’ dam during all seasons in terms of numerical abundance and account for 64% of the total phytoplankton. The zooplankton groups consisted of Maxillopoda, Tubulinea, Eurotatoria and Branchiopoda. Of these, the class Maxillopoda was the predominant component of zooplankton in Serlui ‘B’ dam during all season in terms of numerical abundance and account for 73% of the total zooplankton encountered from the study site. This study provides preliminary report of planktons of Serlui ‘B’ dam.

Rickettsiosis as a critical emerging infectious disease in India

Gram-negative bacteria belonging to the order Rickettsiales such as Anaplasma, Ehrlichia, Neorickettsia, Rickettsia, and Orientia are the causative agents of infectious diseases collectively known as rickettsioses. Of the different rickettsial diseases, spotted fever and scrub typhus have ravaged India for the past couple of centuries. Specifically called the Indian tick typhus, spotted fever was discovered in India in the latter half of the 19th century. After several decades of dormancy, the disease re-emerged in several parts of India. Scrub typhus, originally discovered in Japan, has been recognised to be endemic to a so-called Tsutsugamushi Triangle, extending from Russian Far East and Korea in the north to northern Australia in the south and Afghanistan in the west, but the geographical description has now been breached. Not only in India, scrub typhus has emerged as the leading infectious disease in all endemic areas. Almost all Indian states have records of recurrent outbreaks. Infection can be of dire consequences, as multi-organ dysfunction and neurological disorder (meningocephalitis) are the common complications. This article discusses the historical background and scientific reports of rickettsioses in India.