Research Article

Degrading phenolic compounds and exhausting food reserves stored in the tubers of Cyperus rotundus L. with hydrolytic enzyme

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K Brindha, CR Chinnamuthu

Published on: 28 Mar 2015 | Pages: 1-4

Cyperus rotundus is one of the world worst weeds causes hundred per cent yield loss at times. Killing the mother tubers with the foliar applied herbicide prevent the translocation of herbicides to the secondary and tertiary tubers. Further the tubers can survive during adverse weather condition due to the presence of phenolic compounds and the food reserve.  Hence an experiment was carried out with hydrolytic enzyme to degrade the phenolic compounds (germination inhibitor), to stimulate the germination and exhaust the food reserve in the tubers of weeds to kill before emerging. In the first attempt four different concentration of alpha amylase (50, 100, 150 and 200 ppm) and three different durations (6, 12 and 24 hours) were evaluated. In the second attempt six different concentrations (250, 500, 750, 1000 and 1250 ppm) of alpha amylase were tested for 72 hours. The biochemical parameters namely starch (Anthrone method), amylose (Rapid method) and phenols (Spectrophotometric method) were recorded at hourly intervals and viability of the tubers was tested following tetrazolium test. In the present study, it is observed that treating the tubers of purple nut sedge with alpha-amylase at 200 ppm recorded the minimum content of starch (50 mg g-1) and maximum content of amylose (39 mg g-1) after 24 hours of soaking. Alpha-amylase acts on starch and breaks into glucose molecules, which may be due to the hydrolysis of starch to glucose and maltose by the alpha amylase enzyme. Soaking of alpha-amylase enzyme at 1250 ppm has recorded the minimum content of starch of 32 and 39 mg g-1 in the whole as well as cut tubers, respectively. Thus the hydrolytic enzyme, alpha-amylase effectively degraded the food reserve leading to death of tubers before emerging out

Genetic diversity studies in thermosensitive genic male sterile lines in rice (Oryza sativa L.)

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Genetic divergence of twenty eight Thermo-sensitive Genic Male Sterile lines in rice was studied for twelve characteristics.  Among the traits studied, panicle exertion contributed the most for the genetic diversity of TGMS lines followed by spikelet fertility and stigma length.  The TGMS lines were grouped into twelve clusters, of which cluster VII with five genotypes was the largest and cluster XII was the smallest with one genotype.  The intra cluster distance ranged from 0.00 (cluster XII) to 15.51 (cluster VII).  The inter cluster distance was found to be the highest between clusters III and XII (28.16). When the cluster mean was compared for twelve traits observed, cluster II and X expressed low pollen fertility of less than 1.0 per cent and spikelet fertility of less than 4.0 per cent.  The clusters I, VI and XII recorded the pollen fertility of less than 90 per cent, whereas the clusters VIII, III and IX expressed pollen fertility of 80 per cent and above.  The entries in cluster X had more than 80% of panicle exertion with more than 20o as angle of glume opening.  The stigma length was high with moderate number of spikelets per panicle and panicle length.  Since the TGMS lines in cluster X had more number of desirable traits, they can be effectively utilized for heterosis breeding in rice.

Effect of total electrolyte concentration and sodium adsorption ratio on degree of dispersion of salt affected soils in Maharashtra, India

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Bhargabi Chakraborty

Published on: 28 Mar 2015 | Pages: 9-16

The present investigation was carried out in the Purna valley of Vidarbha region of Maharashtra to study the effect of sodium adsorption ratio with total electrolyte concentration and on degree of dispersion of salt affected soils in Maharashtra. The sampling was done in the month of October, 2013. The soil samples were taken from two sites; at the depth of 0-20 cm (surface soil) and 20- 40 cm (sub-surface soil) respectively. For equilibration of soil samples the synthetic waters were prepared with 4 levels of total electrolyte concentrations (TEC) i.e. 10, 20,40,80 meL-1 with three levels of SAR viz., 5, 10 and 15 mmol1/2L-1/2. Electrolyte concentrations significantly affect the degree of dispersion. With increasing electrolyte concentration degree of dispersion decreases which usually increase the permeability of the soil. Dispersed clay particles clogged the micro pores which ultimately affect the hydraulic conductivity of the soil.

Physical quality characteristics of high yielding two-line hybrids in rice (Oryza sativa L)

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D Dhivyapriya, R Kalaiyarasi

Published on: 28 Mar 2015 | Pages: 17-19

The physical quality characteristics of rice grains are important indicators of grain yield. Grain quality characteristics were studied for fifteen promising hybrids along with its parents. Hulling percent ranged between 68.75 % to 88.70 %. The hybrids namely TS09 22 X CO 43, TS09 22 X CB05/501, TS09 22 X T1408.10, TS09 410 X ADT 38 and TS09 410 X WGL 14 had the highest values of hulling, milling and head rice recovery percentage. Highest kernel length of 5.80 mm was observed in TS09 12 X CB05 911/884. Among all the hybrids analyzed, two hybrids viz., TS09 12 X CB05 911/884 (5.80mm) and TS09 22 X T1408.10 (5.60mm) were seen with medium kernel length category. Out of fifteen hybrids observed, three hybrids were found with medium kernel breadth. Comparing the Length /Breadth ratio, the hybrids namely TS09 22 X T1408.10, TS09 28 X CO 43 were categorized under the medium slender type

Evaluation of metamifop for grass weeds control in direct seeded rice

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S Arunvenkatesh, A Velayutham

Published on: 28 Mar 2015 | Pages: 20-22

Field experiment was conducted to evaluate the bio-efficacy of Metamifop 10 EC and its phytotoxicity and residues in direct seeded rice. The treatments comprised of different weed management practices viz., metamifop 10 EC at 50, 75, 100 and 125 g a.i ha-1 at 2-3 leaf stage of weeds; metamifop 10 EC at 50, 75, 100, 125 and 200 g a.i ha-1 at 5-6 leaf stage; Pre-emergence application of pretilachlor S at 0.45 kg a.i ha-1 as pre emergence with one hand weeding on 30 - 35 DAS ; cyhalofop butyl 10 EC at 100 g ai ha-1 as post emergence herbicide at 15 DAS: weed free check and unweeded control. The common weeds of the experimental field consisted of grasses, sedges and broad leaved weeds (BLW). Application of metamifop 10 EC at 125 g ai ha-1 sprayed at 2-3 leaf stage was comparable with pretilachlor S at 0.45 kg a.i ha-1 as pre emergence with one hand weeding on 30 - 35 DAS in the control of grasses at 30 and 60 DAS. Metamifop 10 EC at 125 g a.i ha-1 at 2-3 leaf stage and metamifop 10 EC at 200 g a.i ha-1 at 5-6 leaf stage was better in controlling grass weeds than pretilachlor S at 0.45 kg a.i ha-1 as pre emergence with one hand weeding on 30-35 DAS at  30 DAS.  For direct seeded low land rice post-emergence application of metamifop 10 EC at 2-3 leaf stage was found to be effective in controlling grass weeds than application of metamifop 10 EC at 5-6 leaf stage. Metamifop 10 EC at 125 g a.i ha-1 at 2-3 leaf stage was found to be best in controlling grass weeds

Screening for shoot fly resistance in sorghum (Sorghum bicolor (L.) Moench)

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P Ranjith, RB Ghorade, VVV Kalpande

Published on: 28 Mar 2015 | Pages: 23-28

The present study was carried out with 26 derived lines for shoot fly resistance and three checks, to estimate the various variability parameters and heritability. Two sets of planting were done, first planting was done to record observations on yield and yield contributing traits. Second planting was done for screening of shoot fly reaction under artificial epiphytic conditions; late planting technique and infector row technique were used for creating sufficient shoot fly pressure. The analysis of variance revealed that significant difference among genotypes for all the traits, suggesting presence of wide range of variation among the genotypes for all the characters under study. Mean values for the lines AKENT - 101, AKENT - 104, AKENT - 107, AKENT - 117, AKENT - 123, AKENT – 125 and IS 18551, showed shoot fly reaction, these lines exhibiting comparatively low number of eggs per plant, minimum  dead  heart  count, low chlorophyll content index and high trichome density per mm2. High heritability (broad sense) was recorded for trichome density per mm2 due to high additive gene action

Heterosisanalysis for grain yield and yield component traits in rice (Oryza sativa L.)

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R Premkumar, RP Gnanamalar , CR Anandakumar

Published on: 28 Mar 2015 | Pages: 29-33

An investigation in rice was undertaken to study the nature and magnitude of heterosis for yield and yield component traits involving ten high yielding lines and three superior grain quality testers and thirty hybrids were developed through line x tester mating design. Observations were recorded for days to 50% flowering, plant height, number of productive tillers per plant, panicle length, number of filled grains per panicle, hundred grain weight and single plant yield. Significant heterosis for grain yield and yield component traits were observed in most of the hybrids. Nine hybrids exhibited positive and significant heterosis over standard check but six crosses over better parent for single plant yield plant. Standard heterosis and heterobeltiosis for grain yield ranged from -15.64 to 20.04% and -23.75 to 15.50%, respectively. A total of four hybrids viz., ADT 39 x I.W.Ponni, ADT 43 x I.W.Ponni, ADT 49 x I.W.Ponni and CO (R) 50 x I.W.Ponni were recorded higher grain yield over both better parent and standard check and were identified as best hybrids for exploiting hybrid vigor. Most of the heterotic crosses for grain yield per plant were accompanied by heterosis for two or more component traits

Biobase synthesis of silver nanoparticles using leaf extract of Calotropis procera

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K Vinothkumar, C Udayasoorian

Published on: 28 Mar 2015 | Pages: 34-38

Development of biologically inspired experimental process for the synthesis of nanoparticles is an important branch of nanotechnology. Biosynthesis of nanoparticles using plant extracts is currently under exploitation. In view, the present work on synthesis of silver (Ag) nanoparticles using biomolecules from leaf extract Calotropis procera was investigated. The complete reduction of silver ions was noticed after 48 h of reaction at 300C under shaking condition. Synthesized nanoparticles were characterized using UV-Vis spectroscopy, XRD and SEM. The silver nanoparticles were predominately spherical in shape and polydispersed in nature with an average size of 55 nm

Characterization of cry Genes from Native Bacillus thuringiensis (Bt) isolates

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M Sivaji , D Girija

Published on: 28 Mar 2015 | Pages: 39-43

In this study, cry genes were amplified by cry4 gene primers from the isolates of Bt-23, Bt-133, Bt-190, and Bt-242 and sequences was carried out. Different computer algorithms were used to analyze the nucleotide sequences obtained from the isolates Bt-23, Bt-133, Bt-190 and Bt-242. Homology search of nucleotide sequences obtained from isolates Bt-23, Bt-133, Bt-190, and Bt-242 with showed homology with cry4A, cry4D, cry4BLB and other dipteran specific insecticidal genes, There were five open reading frames in Bt-23cry4, with the longest one located on +3 strand starting from base 279 to 683, having a length of 405 bases. The A+T and G+C base pair composition was 60.6 per cent and 39.4 per cent in  Bt-23cry4, while Bt-133cry4 A+T was 61 per cent and G+C was 38.8 per cent. Bt-190cry4 was comparatively rich in A+T (64.3%) among all sequences with very low G+C (35.7%). In contrast, Bt-242cry4 was comparatively low in A+T content (57.2%) than the other gene sequences

Review Article

A need of heterosis in mungbean (Vigna radiata L.) for the pulses crop improvement-special review

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Heterosis is a complex phenomenon manifested in the superiority of a hybrid in one (or) more characters over its parents. In other words, heterosis refers to increase in fitness and vigour over the parental values. Heterosis is the increase in vigor that is observed in progenies of matings of diverse individuals from different species, isolated populations or selected strains within species or populations. Heterosis has been of immense economic value in agriculture and has important implications regarding the fitness and fecundity of individuals in natural populations. Considering  mungbean (Vigna radiata (L.) Wilczek), a pulse crop which is self-pollinated, little work has been done on heterosis. This genetic tool is the basic mechanism in developing mungbean cultivars with high yielding potentials. The increase in pulses production volume comes mainly from the increase in mungbean cultivated area. A possible breakthrough for this production limitation is to exploit hybrid vigor of the F1 for possible production of hybrid varieties. The magnitude of hybrid vigor is normally presented in terms of heterosis (superiority of the F1 hybrid over its parental mean) and heterobeltiosis (superiority of the F1 hybrid over its better parent). Existence of a significant amount of dominance variance is essential for undertaking heterosis breeding programme