Purification and partial characterization of acetic acid esterase from malted finger millet (Eleusine coracana, Indaf-15)

Acetic acid esterase (EC 3.1.1.6) cleaves the acetyl groups substituted at O-2/O-3 of the xylan backbone of arabinoxylans and is known to modulate their functional properties. To date, this enzyme from cereals has not received much attention. In the present study, acetic acid esterase from 72 h ragi malt was isolated and purified to apparent homogeneity by a four-step purification, i.e., ammonium sulfate precipitation, DEAE-cellulose, Sephacryl S-200, and phenyl-Sepharose column chromatography, with a recovery of 0.36% and a fold purification of 34. The products liberated from alpha-NA and PNPA by the action of purified ragi acetic acid esterase were authenticated by ESI-MS and 1H NMR. The pH and temperature optima of the enzyme were found to be 7.5 and 45 degrees C, respectively. The enzyme is stable in the pH range of 6.0-9.0 and temperature range of 30-40 degrees C. The activation energy of the enzymatic reaction was found to be 7.29 kJ mol-1. The apparent Km and Vmax of the purified acetic acid esterase for alpha-NA were 0.04 microM and 0.175 microM min-1 mL-1, respectively. The molecular weight of the native enzyme was found to be 79.4 kDa by GPC whereas the denatured enzyme was found to be 19.7 kDa on SDS, indicating it to be a tetramer. EDTA, citric acid, and metal ions such as Fe+3 and Cu+2 increased the activity while Ni+2, Ca+2, Co+2, Ba+2, Mg+2, Mn+2, Zn+2, and Al+3 reduced the activity. Group-specific reagents such as eserine and PCMB at 25 mM concentration completely inhibited the enzyme while iodoacetamide did not have any effect. Eserine was found to be a competitive inhibitor.     

Misidentification of Macrotyloma sar-garhwalensis R.D.Gaur & L.R.Dangwal and its implication in horsegram germplasm management

Genetic Resources and Crop Evolution - Correcting taxonomic misidentifications is crucial to ensuring the conservation and use of wild relatives in crop breeding programmes. Macrotyloma...     

Village seed systems and the biological diversity of millet crops in marginal environments of India

The study relates village seed systems to biological diversity of millet crops grown by farmers in the semi-arid lands of Andhra Pradesh and Karnataka, India. In these subsistence-oriented, semi-arid production systems the environment is marginal for crop growth and often there is no substitute for millet crops. Across communities, farmers grow 13 different combinations of pearl millet, sorghum, finger millet, little millet, and foxtail millet varieties, but individual farmers grow an average of only 2–3 millet varieties per season. The “village seed system” in this study refers to all channels through which farmers acquire genetic materials, separate from or in interaction with the commercial seed industry, observed at the local level. Data are compiled through household surveys and interviews with traders and dealers in village and district markets. Based on the concept of the seed lot, several seed system parameters are defined and measured by millet crop. Most seed transactions, including gifts of seed, appear to be monetized. Seed supply channels differ by improvement status of the genetic material. Regression results confirm that seed system parameters are statistically significant determinants of the spatial diversity of millet crops measured at the village level. Furthermore, both the trade through weekly village markets (shandies) and through the formal seed supply channel contribute positively to the breadth of genetic materials in these communities. Ways should be found to strengthen and improve the overall efficiency of the seed system, including both formal and informal channels, in order to reduce the costs to farmers of procuring and managing diverse crop varieties.     

On the occurrence, distribution, taxonomy and genepool relationship of Cucumis callosus (Rottler) Cogn., the wild progenitor of Cucumis melo L. from India

Recent research point to the Indian wild taxa of Cucumis callosus (Rottler) Cogn. as the wild progenitor of melon (C. melo L.). Overlapping distribution with cultivated and weedy and feral forms of melo and normal fertility of F₁ and BC₁ generations of its cross with cultivated melon indicate its progenitor status. A perusal of herbarium data indicate its natural distribution pattern in the region comprising Vindhya Hills and Aravalli mountain ranges extending northwards to Indo-Gangetic plains and southwards to the Deccan plateau touching rain shadow areas of Western Ghats. Characterised by drought tolerance and field resistance to a host of pests and diseases, it is conspicuously absent in the high rainfall areas of Western Ghats and upper Himalayan region. Based on its morphological distinction and F₁ and BC₁ fertility with C. melo, a subspecific rank within C. melo is postulated. First-hand information on its occurrence, distribution and crossability relationship with other Indian taxa of Cucumis are given.     

On the occurrence,distribution and taxonomy of Cucumis setosus Cogn., an endemic wild edible vegetable from India

Cucumis setosus Cogn. is a rare, endemic, wild gathered or semi-domesticated vegetable restricted to Maharashtra state and border districts of adjoining states in India. Herbarium and literature survey shows that it is poorly collected and inadequately studied. Morphological characters, basic chromosome number and crossability barriers indicate that Cucumis setosus is a valid species, distinct from C. sativus and endemic to western India. Its morphology, basic cytology, crossability relationship with other Cucumis species, taxonomy, distribution, ecology, conservation, economic importance and viability under cultivation are discussed. Besides, a key to distinguish it from C. sativus var. hardwickii (wild and feral form of C. sativus) and other species having sympatric distribution in the area is also presented. Absence of bitter principle in the fruits makes it a potential germplasm for melon and cucumber improvement as well as direct domestication as a future crop.     

Seed variability in <Emphasis Type="Italic">Madhuca longifolia</Emphasis> (Koenig) J. F. Macbride,a source of oil for use as bio-energy

Madhuca longifolia (Koenig) J. F. Macbride is native to India. Seeds contain 20–50% oil (Mahua oil) and the seed cake is used as manure. Mahua oil is used by rural communities for protection against storage pests. Almost all parts of this tree have medicinal properties. Four explorations and collection missions was conducted during July–October 2007 in Tamil Nadu and the Union Territory of Puducherry. This resulted in the collection of 55 accessions. Characterisation and analysis of 7 seed characters were done. The existence of enormous variability in seed length, thickness and 100 seed weight indicates scope for utilization of these accessions for selection of promising material for extraction of oil. Oil content of kernels has been evaluated. Kernel oil ranged from 44.43 to 61.50%. Three accessions IC556617 with 61.50, IC556632 with 60.80 and IC556632 with 60.55% of kernel oil are superior to the rest. Further collections in the site of these oil rich accessions are promising for more productive Madhuca longifolia genetic resources.     

Seasonal Activity of Ticks on Small Ruminants in Tamil Nadu State,India

The seasonal activity of ticks on sheep and goat populations was examined from December 2000 to November 2001 in the state of Tamil Nadu, India. This longitudinal study spread over four seasons and seven agroclimatic zones took into consideration the spectrum of species involved, the levels of infestations, the seasonal epidemiology of ticks and the associated management practices. The most common species of tick spread throughout the state was Haemaphysalis bispinosa followed by Rhipicephalus haemaphysaloides, Hyalomma marginatum isaaci and Hyalomma anatolicum anatolicum with mixed infestations being the rule. Although the infestations were found throughout the year, they were greater during the rainy season and rainfall seemed to be the most important climatic factor affecting seasonal variation. In general, most of the small-ruminant populations carried moderate tick burdens with mixed infestations and this varied with the management practices.     

Development of recombinant nucleocapsid protein based IgM-ELISA for the early detection of distemper infection in dogs

An IgM-ELISA based on a 16-kDa recombinant protein produced for the conserved and functional middle region of nucleocapsid protein of Canine distemper virus was developed. Out of 70 serum samples from distemper-suspected and vaccinated dogs analyzed, 34 serum samples (49%) were positive. The specificity of this ELISA was confirmed by blocking and adsorption experiments. The IgM-ELISA based on the recombinant nucleocapsid protein showed a strong correlation (r=0.857, p<0.0001 at 95% CI) and good agreement (kappa=0.714) with the conventional Vero cell culture distemper antigen based IgM-ELISA. The percent positivity was more in dogs with systemic signs (62%) by recombinant nucleocapsid protein IgM-ELISA. Out of 70 clinical serum samples, 69 samples were used along with 4 control sera used in the IgM-ELISA for the detection of viral RNA by Slot blot hybridization and 26 of them (36%) were positive. Fifty-one percent agreement was observed between the recombinant nucleocapsid protein IgM-ELISA and Slot blot hybridization. The analysis of clinical history of the dogs with systemic signs supported the application of IgM-ELISA over Slot blot hybridization in the early detection of distemper infection.     

Status of crop plants of agricultural importance in Kerala state,India: an update

The state of Kerala in India, a part of the Western Ghats–Sri Lanka biodiversity hotspot, is blessed with rich biodiversity including agrobiodiversity. Richness in crop diversity is attributed to the wide topographic and climatic niches, long history of outside contacts, personal craving for experimenting new crops, practice of high-density multi-species cropping system, etc. Evidence from several field exploration trips, herbarium survey, reliable literature and other sources has revealed that 306 crop taxa (excluding medicinal and aromatic plants, ornamentals and forestry species) belonging to 290 species coming under 179 genera and 61 families, are being cultivated in different areas of this state. This includes crops belonging to crop-groups—cereals and millets (11), pseudocereals (2), pulses (7), oilseeds (7), fibres (3), forages (14), fruits and nuts (107), vegetables (86; 18-being tuber crops), spices and condiments (20), plantation crops (10) and others (29). Of 306 taxa, 63 occur in the wild state as well; 43 are of only recent cultivation (<?15 years) or under trial cultivation by innovative farmers; and 43 are confined only in (sub)temperate hills. This is more than double (104% increase) the earlier estimate of crops made during 2011, which also included species of medicinal/aromatic/ornamental value (5), not under cultivation in Kerala (3), mistaken identity (3) and synonym (1). We provide here user-friendly crop-group wise categorization of taxa with their vernacular names for easy cross reference. This communication also discusses about the issue of botanical misidentification of crop plants, species of doubtful cultivation status, specialty crops, potential exotic crops, etc.

     

Collection of plant genetic resources from Andaman and Nicobar Islands

The Andaman and Nicobar (A&N) group of islands is immensely rich in plant biodiversity. Andaman’s native tribes are hunter-gatherers, sustaining on wild or marine food and practically do not have any cultivation. Diversity in cultivated crops is presently maintained in home gardens by settlers from the mainland and other adjoining countries. The National Bureau of Plant Genetic Resources (NBPGR) through explorations either alone or in association with CARI or with other ICAR institutes has collected 1234 accessions in 48 exploration and collection missions. Variability was collected in rice, cowpea, black gram, green gram, okra, Chinese spinach, ash gourd, taro, cucumber, pumpkin, bottle gourd, ridge gourd, bitter gourd, chilli, greater yam and coconut. Indigenous landraces are absent. The in situ conservation of the wild relatives of crops is well taken care of by a large number of protected forest reserves.