A Study on the Genetic Variability and Genetic Control of the Important Morphometric Characters of Curcuma aeruginosa Roxb.

2016 ◽  
Vol 23 (2) ◽  
pp. 61-65
Author(s):  
V. Soorya ◽  
V. Radhakrishnan ◽  
K. Mohanan
Keyword(s):  
Genetic Variability ◽  
Genetic Control ◽  
Continuous Distribution ◽  
Low Frequency ◽  
Wide Distribution ◽  
Leaf Length ◽  
Contributing Factors ◽  
Morphometric Characters ◽  
Polygenic Control ◽  
Balanced Distribution

Curcuma aeruginosa Roxb., the pink and blue ginger is an underutilized rhizomatous herb used in the Indian as well as Thai and Malaysian systems of traditional medicine.Its antioxidant and nutraceutical properties have also been explored recently. However, no effort has been made to study the genetic variability and genetic control of the agronomic morphometric characters of this species. Hence the present study was carried out to analyse the genetic variability and genetic control of such characters in the species.All the fifteen morphometric characters showed continuous distribution indicating their polygenic control. Among the growth characters, plant height, leaf length, leaf breadth and leaf area showed accumulation of higher number of dominant alleles in their gene pool and number of tillers and number of leaves per tiller showed higher accumulation of recessive factors. Among the yield characters, length of primary fingers and length of secondary fingers showed a balanced distribution of genotypes, number of primary fingers, number of secondary fingers, diameter of primary tillers, length of mother rhizome and yield per plant showed skewness towards the assembly of higher number of recessive factors and diameter of primary fingers and diameter of secondary fingers showed skewness towards the assembly of dominant contributing factors. However, all the characters under study showed comparatively wide distribution of factor combinations, indicating the broad genetic base of the population under study. However, most of the agronomically important characters showed very low frequency of genotypes with higher number of dominant factors indicating the necessity of selecting superior genotypes to develop improved varieties.

Genetic variability and demographic history of Heliothis virescens (Lepidoptera: Noctuidae) populations from Brazil inferred by mtDNA sequences

2011 ◽  
Vol 102 (3) ◽  
pp. 333-343 ◽  
Author(s):  
K.C. Albernaz ◽  
K.L. Silva-Brandão ◽  
P. Fresia ◽  
F.L. Cônsoli ◽  
C. Omoto
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Heliothis Virescens ◽  
Demographic History ◽  
Haplotype Diversity ◽  
Low Frequency ◽  
Haplotype Network ◽  
Demographic Expansion ◽  
Significant Genetic Structure ◽  
History Of

AbstractIntra- and inter-population genetic variability and the demographic history of Heliothis virescens (F.) populations were evaluated by using mtDNA markers (coxI, coxII and nad6) with samples from the major cotton- and soybean-producing regions in Brazil in the growing seasons 2007/08, 2008/09 and 2009/10. AMOVA indicated low and non-significant genetic structure, regardless of geographical scale, growing season or crop, with most of genetic variation occurring within populations. Clustering analyzes also indicated low genetic differentiation. The haplotype network obtained with combined datasets resulted in 35 haplotypes, with 28 exclusive occurrences, four of them sampled only from soybean fields. The minimum spanning network showed star-shaped structures typical of populations that underwent a recent demographic expansion. The recent expansion was supported by other demographic analyzes, such as the Bayesian skyline plot, the unimodal distribution of paired differences among mitochondrial sequences, and negative and significant values of neutrality tests for the Tajima's D and Fu's FS parameters. In addition, high values of haplotype diversity (Ĥ) and low values of nucleotide diversity (π), combined with a high number of low frequency haplotypes and values of θπ<θW, suggested a recent demographic expansion of H. virescens populations in Brazil. This demographic event could be responsible for the low genetic structure currently found; however, haplotypes present uniquely at the same geographic regions and from one specific host plant suggest an initial differentiation among H. virescens populations within Brazil.

Low Frequency of Adenylate Kinase Release into Cerebrospinal Fluid during Balanced, Normotensive Anaesthesia and a Non-Orthognathic Surgical Procedure

1997 ◽  
Vol 25 (2) ◽  
pp. 92-97 ◽  
Author(s):  
M Enlund ◽  
O Mentell ◽  
L Edmark ◽  
G Ronquist
Keyword(s):  
Cerebrospinal Fluid ◽  
Adenylate Kinase ◽  
Orthognathic Surgery ◽  
Cell Injury ◽  
Low Frequency ◽  
Brain Cell ◽  
Contributing Factors ◽  
Oscillating Saw ◽  
The Difference ◽  
Increased Activity

Activity of strictly intracellular enzymes in the cerebrospinal fluid (CSF) may indicate leakage from dysfunctional brain cells. Increased activity of adenylate kinase (AK) in the CSF is indicative of brain cell injury arising from several sources, among them orthognathic surgery. The mechanism in the latter case is obscure, but the use of an oscillating saw which generates vibrations, and the site of surgery close to the brain may be contributing factors. Anaesthesia may also play a role. In the present study, CSF-AK activity was measured after hysterectomy and was compared with activity after orthognathic surgery in two other studies. Four of 19 patients (21%) in the present study expressed pathological activity, compared with 34 of 47 (72%) orthognathic patients in the two other studies. No firm conclusion may be drawn from historical comparisons, and the difference in activity seen between the two types of surgery might not necessarily be the result of surgical factors. Until this is investigated further, however, we conclude that there may be a difference in postoperative CSF-AK activity between orthognathic and lower abdominal surgery.

GENETIC VARIABILITY AND INTERRELATIONSHIP AMONG MORPHOLOGICAL TRAITS IN AFRICAN PEAR FRUIT (DACRYODES EDULIS (G.DON) H.J. LAM) ACCESSIONS

2020 ◽  
Vol 19 (1) ◽  
pp. 46-59
Author(s):  
V. I. ALAJE ◽  
C. O. ALAKE
Keyword(s):  
Genetic Variability ◽  
Total Variation ◽  
Morphological Traits ◽  
Biomass Accumulation ◽  
Leaf Length ◽  
Root Weight ◽  
Pear Fruit ◽  
Leaf Weight ◽  
Dacryodes Edulis ◽  
African Pear

African pear fruit (Dacryodes edulis) is a highly sought for multipurpose agroforestry tree species that has the potential for both local and international trades, Nigeria is among the leading producer of the fruit, but its pattern and extent of its genetic variability is currently unknown. Hence, a study was carried out to determine the pattern and extent of genetic variability and interrelationships among 13 morphological traits of African pear fruit accessions. The experiment was laid in a Completely Randomized Design in 5 replications. Data collected on number of leaf production, leaf length,  leaf breadth,  leaf length/breadth ratio,  internode distances, plant height, collar diameter, fresh leaf weight, fresh stem weight, fresh root weight, dry leaf weight, dry stem weight, dry root weight and  biomass accumulation were subjected to Analysis of Variance. Treatment means were separated using Duncan’s Multiple Range Test at 5% probability level. Results showed significant (p<0.05) differences among the D. edulis genotypes for most of the traits evaluated  indicated variation in the performance of the genotypes and  pattern of clustering indicated that there was no association between eco-geographical distribution of genotypes and genetic diversity. PCA revealed that fourteen axes accounted for 100% of the variations observed while the first five axes contributed 73.23% of the total variation observed. The first axis accounted for 25.61% of the total variation while the second and third accounted for 15.43 and 15.01%, respectively. The fourth axis contributed 9.82% of the total variation while the fifth axis contributed 7.36% of the total variation. Significant phenotypic and genotypic correlations were observed between most of the plant characters evaluated and biomass accumulation  which is an indication that the phenotypic association will be a good index for the genotypic association.  

scholarly journals Genetic Variability, Character Association and Path Analysis in Boro Rice (Oryza sativa L.) Germplasm from Bangladesh

2019 ◽  
Vol 22 (1) ◽  
pp. 35-43
Author(s):  
MZ Islam ◽  
T Chakrabarty ◽  
N Akter ◽  
ESMH Rashid ◽  
M Khalequzzaman ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Coefficient Of Variation ◽  
Oryza Sativa L ◽  
Block Design ◽  
Crop Improvement ◽  
Leaf Length ◽  
Component Traits ◽  
High Heritability ◽  
Positive Significant Correlation ◽  
Boro Rice

The success of varietal development programmme largely depends on the nature and magnitude of genetic variability, heritability and characters association of the crop. The objective of the present study was to estimate the extent of genetic variability and relation between yield and related characters of rice. Forty Boro rice germplasm were evaluated in a randomised complete block design with three replications. Analysis of variance indicated significant differences among the genotypes for 14 quantitative characters. The presence of slightly higher phenotypic coefficient of variation than genotypic coefficient of variation indicated the negligible influence of environment on the expression of yield and its component traits. Leaf length, days to flowering, days to maturity and 1000 grain weight showed highly positive significant correlation present with yield hill-1. High heritability had been observed for yield contributing traits during the study, suggested that these traits would respond to selection owing to their high genetic variability and transmissibility. Therefore, a thorough understanding of the inheritance of traits, their heritability and relationship with other important characteristics is important for the choice of breeding and selection methods for crop improvement. Bangladesh Rice j. 2018, 22(1): 35-43

scholarly journals The use of cotyledon proteins to assess the genetic diversity in sweet holm oak

2009 ◽  
Vol 55 (No. 11) ◽  
pp. 526-531 ◽  
Author(s):  
A. Martín M ◽  
R. Navarro-Cerrillo ◽  
P. Ortega ◽  
B. Alvarez J
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Quercus Ilex ◽  
Storage Proteins ◽  
Allelic Variation ◽  
Seed Proteins ◽  
Wide Distribution ◽  
Holm Oak ◽  
Additional Tool ◽  
The Mediterranean Basin

Sweet holm oak (<I>Quercus ilex</I> ssp. <I>ballota</I> Desf. Samp.) is an important broad-leaved tree spread in the Mediterranean basin. In Spain, few studies on the genetic variability of this species have been displayed. Storage seed proteins are a useful tool in the evaluation of the genetic variability of many species. The objective of this study was to analyze the usefulness of cotyledon proteins as markers of the genetic diversity in sweet holm oak. The evaluated populations were highly polymorphic for the glutelins, being detected up to 32 polymorphic bands with a wide distribution among all them. Considering all evaluated populations, about 35.8% of the total allelic variation was distributed among populations. This method of analysis of cotyledon storage proteins (glutelins) could be considered an additional tool for the evaluation of genetic diversity in this species.

Induced gene and chromosome mutants

1981 ◽  
Vol 292 (1062) ◽  
pp. 457-466 ◽  
Keyword(s):  
Genetic Variability ◽  
Genetic Control ◽  
Genetic Manipulation ◽  
Point Mutations ◽  
Personal Communication ◽  
Agricultural Plant ◽  
Plant Trait ◽  
Breeding Research ◽  
Induced Mutants

Plant scientists, including breeders, can use an arsenal of physical and chemical mutagens and appropriate selection techniques to ‘manufacture’ in their experimental plots gene and chromosome mutants to compensate for the erosion of natural sources of genetic variability. They also have the capability of generating in this type of genetic manipulation the entire array of genetic variation inherent in all loci controlling each plant trait, and thus in a relatively short time producing most, if not all, of the genetic variants that have ever occurred in the evolution of a given agricultural plant. This capability is required not only for the breeder concerned with developing new cultivars to meet the numerous and varied demands of the modern farmer, processer and consumer, but also for the geneticist, physiologist, anatomist and biochemist concerned with unravelling important plant processes and their genetic control. In short, these scientists need inexhaustible supplies of genetic variability, often never before selected in Nature or by earlier plant breeders. Numerous experiments demonstrate that induced mutants have considerably extended the genetic variability of a phenotype. An outstanding example is eceriferum (‘waxless’ plant surfaces) in barley. Spontaneous mutations produced several well known variants controlled by about six loci. Genetic analyses of over 1300 induced and the few spontaneous mutants have determined that this trait is controlled by at least 77 loci (Lundqvist 1976, and personal communication). There are numerous alleles at some of these loci. Other examples are described in this paper. The quantity and quality of artificially induced genetic variability in plants is in no small part due to the contributions of improved mutagens, mutagen treatments and selection techniques. A new potent and unique mutagen, sodium azide, is particularly successful in inducing putative point mutations. Recent experiments with barley and Salmonella have revealed that it is not azide per se but an activated metabolite that is the mutagenic agent. The metabolite has been isolated and crystallized and can now be synthesized in vitro . These findings usher in a new category of mutagens and suggest new avenues for understanding the interaction of mutagens with chromosomes and genes and for greater control of the induction of genetic variability in plants. The considerable success of varietal development through induced mutants is well documented: 465 culvitars of sexually and vegetatively reproducing crops have been released that owe some of their production advantage to an induced gene or chromosome mutant. These cultivars have led to considerable economic impact in a number of countries. In breeding research, induced mutants are indispensable for probing and elucidating the pathway and genetic control of important plant processes such as wax synthesis and deposition (von Wettstein-Knowles 1979), nitrogen assimilation (Kleinhofs et al . 1980), photorespiration and different facets of photosynthesis (Somerville & Ogren 1980; Miles et al . 1979; Simpson & von Wettstein 1980) . In the manipulation of plant genes (genetic engineering) in breeding research, it becomes increasingly necessary to pinpoint these genes on chromosomes. For this endeavour, an abundant array of induced chromosome mutants such as trisomics, telotrisomics, acrocentrics, inversions, translocations and deletions is required. This important activity can now be complemented by ever-improving chromosome banding techniques.

scholarly journals Partial male sterility and the evolution of nuclear gynodioecy in plants

2002 ◽  
Vol 80 (3) ◽  
pp. 187-195 ◽  
Author(s):  
STEWART T. SCHULTZ
Keyword(s):  
Genetic Variability ◽  
Male Sterility ◽  
Inbreeding Depression ◽  
Low Frequency ◽  
Genetic Models ◽  
Selfing Rate ◽  
Frequency Dependent Selection ◽  
Fitness Advantage ◽  
General Importance ◽  
Classical Models

Gynodioecy, a genetic dimorphism of females and hermaphrodites, is pertinent to an understanding of the evolution of plant gender, mating and genetic variability. Classical models of nuclear gynodioecy attribute the maintenance of the dimorphism to frequency-dependent selection in which the female phenotype has a fitness advantage at low frequency owing to a doubled ovule fertility. Here, I analyse explicit genetic models of nuclear gynodioecy that expand on previous work by allowing partial male sterility in combination with either fixed or dynamically evolving mutational inbreeding depression. These models demonstrate that partial male sterility causes fitness underdominance at the mating locus, which can prevent the spread of females. However, if partial male sterility is compensated by a change in selfing rate, overdominance at the mating locus can cause the spread of females. Overdominance at introduction of the male sterility allele can be caused by high inbreeding depression and a lower selfing rate in the heterozygote, by purging of mutations by a higher selfing rate in the heterozygote, and by low inbreeding depression and a higher selfing rate in the heterozygote. These processes might be of general importance in the maintenance of mating polymorphisms in plants.

scholarly journals Genetic Diversity of 17 Autochthonous Italian Chicken Breeds and Their Extinction Risk Status

2021 ◽  
Vol 12 ◽  
Author(s):  
Dominga Soglia ◽  
Stefano Sartore ◽  
Emiliano Lasagna ◽  
Cesare Castellini ◽  
Filippo Cendron ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Extinction Risk ◽  
Low Frequency ◽  
Effective Number ◽  
Risk Of Extinction ◽  
Chicken Breeds ◽  
Inbreeding Rate ◽  
The Mean ◽  
Endangered Status

The preservation of genetic variability of autochthonous poultry breeds is crucial in global biodiversity. A recent report revealed small breed size and potential risk of extinction of all native Italian poultry breeds; therefore, a correct assessment of their genetic diversity is necessary for a suitable management of their preservation. In this work, we provided an overview of the contribution to poultry biodiversity of some Italian autochthonous breeds reared in conservation centers devoted to local biodiversity preservation. The level of genetic diversity, molecular kinship, inbreeding, contribution to overall genetic diversity, and rate of extinction of each breed were analyzed with a set of 14 microsatellite loci in 17 autochthonous chicken breeds. To evaluate genetic variability, total number (Na), and effective number (Ne) of alleles, observed (Ho) and expected (He) heterozygosity, and F (Wright’s inbreeding coefficient) index were surveyed. The contribution of each analyzed breed to genetic diversity of the whole dataset was assessed using MolKin3.0; global genetic diversity and allelic richness contributions were evaluated. All the investigated loci were polymorphic; 209 alleles were identified (94 of which private alleles). The average number of alleles per locus was 3.62, and the effective number of alleles was 2.27. The Ne resulted lower in all breeds due to the presence of low-frequency alleles that can be easily lost by genetic drift, thus reducing the genetic variability of the breeds, and increasing their risk of extinction. The global molecular kinship was 27%, the average breed molecular kinship was 53%, and the mean inbreeding rate 43%, with a self-coancestry of 78%. Wright’s statistical analysis showed a 41% excess of homozygous due to breed genetic differences (34%) and to inbreeding within the breed (9%). Genetic variability analysis showed that 11 breeds were in endangered status. The contribution to Italian poultry genetic diversity, estimated as global genetic diversity, and ranged from 30.2 to 98.5%. In conclusion, the investigated breeds maintain a unique genetic pattern and play an important role in global Italian poultry biodiversity, providing a remarkable contribution to genetic variability.

scholarly journals Initial responsiveness to darbepoetin alfa and its contributing factors in non-dialysis chronic kidney disease patients in Japan

2020 ◽  
Author(s):  
Terumasa Hayashi ◽  
Hideki Kato ◽  
Kenichiro Tanabe ◽  
Masaomi Nangaku ◽  
Hideki Hirakata ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Darbepoetin Alfa ◽  
Iron Supplementation ◽  
Initial Response ◽  
Wide Distribution ◽  
Renal Outcome ◽  
Contributing Factors ◽  
Modifiable Factors ◽  
The Mean

Abstract Background Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is associated with cardiovascular events and poor renal outcome in patients with chronic kidney disease (CKD). This study aimed to investigate the initial responsiveness to darbepoetin alfa (DA) and its contributing factors using the data from the BRIGHTEN. Methods Of 1980 patients enrolled at 168 facilities, 1695 were included in this analysis [285 patients were excluded mainly due to lack of hemoglobin (Hb) values]. The initial ESA response index (iEResI) was defined as a ratio of Hb changes over 12 weeks after DA administration per weight-adjusted total DA dose and contributing factors to iEResI were analyzed. Results The mean age was 70 ± 12 years (male 58.8%; diabetic nephropathy 27.6%). The median creatinine and mean Hb levels at DA initiation were 2.62 mg/dL and 9.8 g/dL, respectively. The most frequent number of DA administration during 12 weeks was 3 times (41.1%), followed by 4 (15.6%) times with a wide distribution of the total DA dose (15–900 μg). Remarkably, 225 patients (13.3%) did not respond to DA. Multivariate analysis showed that male gender, hypoglycemic agent use, iron supplementation, high eGFR, low Hb, low CRP, low NT-proBNP, and low urinary protein–creatinine ratio were independently associated with better initial response to DA (P =  < 0.0001, 0.0108, < 0.0001, 0.0476, < 0.0001, 0.0004, 0.0435, and 0.0009, respectively). Conclusions Non-responder to DA accounted for 13.3% of patients with non-dialysis CKD. Iron supplementation, low CRP, low NT-proBNP, and less proteinuria were predictive and modifiable factors associated with better initial response to DA.

GENOME RELATIONSHIPS IN BROMUS ERECTUS, B. PUMPELLIANUS SSP. DICKSONII AND B. PUMPELLIANUS

1975 ◽  
Vol 17 (3) ◽  
pp. 391-394
Author(s):  
K. C. Armstrong
Keyword(s):  
Genetic Control ◽  
Chromosome Pairing ◽  
Low Frequency ◽  
Homoeologous Chromosome ◽  
Homoeologous Chromosome Pairing ◽  
Bivalent Formation ◽  
Bromus Erectus

Chromosome pairing was studied in hexaploid (2n = 42) hybrids of B. erectus (2n = 28) × B. pumpellianus (2n = 56) and B. pumpellianus ssp. dicksonii (2n = 28) × B. pumpellianus. Chromosome pairing in the B. erectus × B. pumpellianus hybrid was complete with predominantly bivalent formation and a low frequency of quadrivalents. The pairing results support the contention that B. pumpellianus is an autoalloploid with an AAAABBBB genome formula. The B. pumpellianus ssp. dicksonii × B. pumpellianus hybrid has an AAABBB genome formula. The presence of quadrivalents, hexavalents and cells containing a total number of bivalents or bivalents plus trivalents in excess of 14 indicated pairing between the A and B genomes. However, a high univalent frequency showed that the A and B genomes were homoeologous rather than homologous. Evidence for genetic control of homoeologous chromosome pairing and homoeologous differentiation between the genomes of the species is discussed.

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