Variation of As concentration between soil types and rice genotypes and the selection of cultivars for reducing As in the diet

Chemosphere ◽  
2012 ◽  
Vol 87 (4) ◽  
pp. 384-389 ◽  
Author(s):  
X.X. Ye ◽  
B. Sun ◽  
Y.L. Yin
Author(s):  
Anjani Kumar ◽  
D. N. Singh ◽  
Krishna Prasad ◽  
Avinash Pandey

The present investigation was carried out with F2 plants from a cross between two parents i.e., BPT-5204 and IR-64Drt1. The selection of parents for crosses was made based on genotypes that were tolerant and susceptible to drought condition. BPT-5204 was drought susceptible and IR-64Drt1 was also tolerant to drought. In this experiment adequate amount of variability was detected for grain yield per plant and its components among 324 segregants evaluated under augmented randomized block design II in normal field condition. The analysis of variance for grain yield and its attributing characters among blocks, treatments, entries, checks and checks vs entries revealed presence of significant variation in the segregants studied. However, with respect to checks, non-significant differences were recorded for only L/B ratio. The results indicated that among 324 rice genotypes including checks, only 9 rice genotypes expressed higher yield compared to seven checks varieties under normal field condition. The segregants S-51, S-122, S-135, S-195, S-199, S-210, S-219, S-222, S-251 were top ranking genotypes with respect to all checks.


Rice Science ◽  
2016 ◽  
Vol 23 (4) ◽  
pp. 184-195 ◽  
Author(s):  
Y.C. Aluwihare ◽  
M. Ishan ◽  
M.D.M. Chamikara ◽  
C.K. Weebadde ◽  
D.N. Sirisena ◽  
...  

2017 ◽  
Vol 15 (1) ◽  
pp. 170-181
Author(s):  
MS Ahmed ◽  
Khandakar Md. Iftekharuddaula

Genetic improvement of rice (Oryza sativa L.) for yield is important for increasing demand of the growing population and the changing climate of the world. Recent studies showed that backcrossing twice using modern varieties as receptor and mini core collection as doner, most of the undesirable traits could be improved remarkably and in other words its maximum allele diversity could be brought back into rice fields. Core collection is defined as a subset chosen to represent the most genetic diversity of an initial collection with a minimum of redundancies. The objective of the present study was to review the selection of core collection of Jesso-Balam group of rice genotypes through quantitative, qualitative and molecular characters. Earlier, the same germplasms were characterized for agro-morphological, physico-chemical and molecular characters and grouped into different clusters by different methods at Bangladesh Rice Research Institute during 2009-12. Finally, the core collection was selected by reviewing the above characterized data and using the hierarchical cluster analysis. Moreover, the selection processes of core collection were improved by applying composite evaluation methods; such as agro-morphological traits, biochemical characters and so on, through sampling strategies based on genotypic values, predicted genotypic value, comparing different genetic distances, cluster methods and sampling strategies methods, molecular characterization or SSR marker base data. As a result, the selected core germplasm of Jesso-Balam rice accessions were JBPL1, JBPL8, JBPL9, JBPL10, JBPL13, JBPL15, JBPL16, JBPL17, JBPL19, JBPL20, JBPL21, JBPL23, JBPL25 and JBPL26. In conclusion, the core collection  need to be considered as the ‘working collection’ of Jesso-Balam rice genotypes for their easy and safe conservation and effective utilization in Gene bank.The Agriculturists 2017; 15(1) 170-181


2019 ◽  
Vol 186 (2-3) ◽  
pp. 257-262
Author(s):  
Michal Setnička ◽  
Tomáš Kroupa ◽  
Alena Čtvrtečková ◽  
René Marek

Abstract The objective of this research was to develop a sampling protocol for contaminated soils after a large radiological accident. One of the criteria for good sampling method is reproducibility and accuracy of large number of samples collected in short time. Members of the chemical laboratories of the Fire Rescue Service of the Czech Republic (FRS CR), which are included in Radiation Monitoring Network, tested four tools in different soil types. More than 100 samples were collected. Root auger and square soil sampler seem to be the best for reliable soil sampling. Modifications of the root auger decreased of relative error of sampling to 7.5%. The root auger is recommended as a first-choice sampling tool based on: (1) ease, (2) operator safety, (3) collection of a representative sample (4) applicability to most soil types and (5) enabling collection of depth-discrete samples.


Author(s):  
Amir Al-Khafaji ◽  
Krishnanand Maillacheruvu ◽  
Robert Jacobs

A new technique to assess the reliability of published compression index equations in terms of soil void ratio is presented. Several published equations pertaining to different soil types are examined in terms of accuracy and applicability. The new technique employs regression analysis to examine a substantial number of published compression data objectively. The traditional bias inherent in the selection of the number of data points and the range of void ratios for a given regression equation is eliminated. This was made possible by creating ranges for the compression index irrespective of the data set involved. This technique revealed that a strong correlation exists between the slopes and intercepts of all published equations. The slopes and intercepts of the newly developed regression equations were used to compare several well know published equations to assess accuracy and applicability. The proposed technique permits the examination of the authenticity of any published empirical equations relating to the compression index of clay to void ratio.


2015 ◽  
Vol 1 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Ahasanul Hoque ◽  
Shamsun Nahar Begum ◽  
Lutful Hassan

Diversity at molecular level among thirty rice genotypes, selected based on earliness and morphometric diversity was evaluated through five SSR markers associated with days to heading. Three primers viz., RM147, RM167 and RM215 showed polymorphism for growth duration related traits. A total of 17 alleles were detected among the 30 rice genotypes with an average of 5.66 alleles per locus. Polymorphism Information Content (PIC) ranged from 0.356 to 0.798 with an average of 0.543. A dendrogram based on total microsatellite polymorphism grouped 30 genotypes into four major clusters at 0.39 similarity coefficient differentiating early maturing genotypes from others. This information about the genetic diversity will be very useful for proper identification and selection of appropriate parents for future breeding programs, including gene mapping. The results also showed that microsatellite markers associated to genes or QTLs controlling growth duration properties are suitable tools for marker assisted selection (MAS) to select rice lines with short growth duration. DOI: http://dx.doi.org/10.3329/ralf.v1i1.22354 Res. Agric., Livest. Fish.1(1): 37-46, Dec 2014


2016 ◽  
Vol 8 (1) ◽  
pp. 69-76 ◽  
Author(s):  
A. Mishra ◽  
Pradeep Kumar ◽  
R. S. Sengar ◽  
P. Kumar ◽  
R. Singh ◽  
...  

The study investigates the genetic diversity among the Basmati rice genotypes. Selected nine Basmati rice genotypes were studied for twelve morphological traits, biochemical parameters and for molecular analysis with 11 SSR markers. Pusa Sugandha 5 and Basmati 370, showed strong aroma while other varieties showed medium aroma. Alkali spreading value were intermediate in Basmati 386, Vallabh Basmati 22 and Vallabh Basmati 24 while other varieties showed high values. Pusa Basmati 1 and Basmati 386 showed soft category of gel consistency while in rest varieties it was under medium category. Amylose percentage in grains were ranged from 18.02% (Taraori basmati) to 22.0% (Basmati370). Molecular analysis with 11 SSR markers showed 125 allels with an average number of allels 11.36 per locus. All the markers showed specific type of banding pattern along with 82 polymorphic allels in different genotypes. This study focuses on application of statistical methods and techniques in analysis of genetic diversity of the agronomic data, biochemical aspects related to quality parameters and at the molecular level using SSR markers for clustering procedure making dendrogram that helps the more accurate selection of the superior basmati genotypes for the further studies of the breeders and researchers.


2019 ◽  
Vol 39 (04) ◽  
Author(s):  
Kasturi Majumder ◽  
Disharee Nath ◽  
Rambilash Mallick ◽  
Tapash Dasgupta

Thirty-six rice genotypes were evaluated for thirteen different quality parameters along with yield/plant to assess genetic estimates of the traits and the extent of genetic diversity among the varieties. Analysis of variance was conducted to determine GCV, PCV, heritability and GA of the genotypes with respect to all characters. Significant variation was observed in many traits among the genotypes offering scope for selection. Correlation analysis determined the nature of relationship among these characters. UPGMA studies revealed six major clusters and cluster I and II were the largest with maximum number of genotypes. The study identified that the varieties namely, Black Gora, Kalinga-2, Dudheswar, ARC 10086, IR-36, IR-64 and Nipponbare possessed good quality traits and high yield performance. The current study indicated that developing rice varieties for consumer acceptance with good grain quality traits along with high yield will be very useful in rice breeding and in selection of parents for hybridization to combine both high yield and improved quality traits.


2017 ◽  
Vol 20 (2) ◽  
pp. 13-19
Author(s):  
MA Siddique ◽  
M Khalequzzaman ◽  
MZ Islam ◽  
ESMH Rashid ◽  
MHK Baktiar ◽  
...  

Assessment of genetic diversity is essential for germplasm characterization, utilization and conservation. Genetic diversity of 31 Aus rice genotypes of Bangladesh was assessed using 11 ILP (intron length polymorphism) markers. A total of 28 alleles were detected and the number of alleles per locus varied from 2 (RI01779, RI05751, RI05304, RI03205, RI00299, RI05407) to 4 (RI05559). The PIC values ranged from 0.06 (RI05407) to 0.57 (RI05559) with an average of 0.33. PIC value revealed that RI05559 was the best ILP markers for the studied 31 Aus rice genotypes. The dendrogram from unweighted pair-group method with arithmetic average clustering classified the genotypes into five groups at a coefficient of 0.57. Two dimensional graphical views of Principal Coordinate Analysis (PCoA) revealed that the genotypes Kuchmuch, Kalo dhan, Aus dhan, Sadey aus, Chaina and Dighi bawalia were found far away from the centroid of the cluster and can be seslected as parents for further breeding programmes. Parangi and V3, Adubali and H1-2, Begunbichi and Hashikalmi had closest distance (0.000) in the distance matrix might have same genetic background. This information will be useful for the selection of genetically diversed parents and assist in trait development using genotypes in rice breeding programmes in future. The results provided some useful implications for establishment of sovereignty of Bangladeshi rice gene pool. It was also suggested that ILP markers could be very useful for the genetic study and breeding in rice.Bangladesh Rice j. 2016, 20(2): 13-19


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