An isozyme-based assessment of the genetic variability within the Daucus carota complex (Apiaceae: Caucalideae)

1990 ◽  
Vol 68 (11) ◽  
pp. 2449-2457 ◽  
Author(s):  
Michel D. St. Pierre ◽  
Randall J. Bayer ◽  
I. Michael Weis

Daucus carota sensu lato is a phenotypically variable Eurasian species complex that has been naturalized and cultivated worldwide. One hundred and sixty-eight accessions from 32 countries were surveyed by enzyme electrophoresis to determine the extent of genetic variation present in the species. Eight enzyme systems coded by 16 putative loci were surveyed. They indicate that the recognized subspecies have diverged only slightly from one another with respect to the enzymes surveyed. The samples of wild taxa are more genetically diverse than those of the cultivated taxa, but not significantly different with respect to the mean number of alleles per locus, the proportion of polymorphic loci, the observed and expected heterozygosities, or Nei's genetic diversity statistics (P > 0.05). Members of the aggregate group gingidium have significantly lower total gene diversity within a taxon (P <.05) than do members of the aggregate group carota, as well as lower gene diversity within populations of the taxa (P < 0.01). Thus allozyme divergence is concordant with morphological divergence. Cultivars with carotene-pigmented roots show negligible amounts of genetic divergence. They appear to have evolved in a simple pattern after an initial genetic bottleneck. Key words: Daucus carota, isozyme, electrophoresis, genetic variability.

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 353
Author(s):  
Małgorzata Goleman ◽  
Ireneusz Balicki ◽  
Anna Radko ◽  
Iwona Rozempolska-Rucińska ◽  
Grzegorz Zięba

The aim of the study was to assess the genetic variability of the Polish Greyhound population based on pedigree analysis and molecular DNA testing and to determine the degree of relatedness among individuals in the population. Pedigree data of 912 Polish Greyhounds recorded in pedigree books since they were opened for this breed were analyzed. For molecular testing, DNA was obtained from cheek swabs taken from 235 dogs of the tested breed. A panel of 21 markers (Short Tandem Repeat—STR) was used. The mean inbreeding determined for the Polish Greyhound population based on pedigree analyses was low and amounted to 11.8%, but as many as 872 individuals of the 912 dogs in the studied population were inbred. A total of 83 founders (at least one unknown parent) were identified, among which 27 founders had both unknown parents. Full-sibling groups consisted of 130 individuals, with a minimum and maximum litter size of 2 and 16, respectively. The average litter size was 5.969. Gene diversity calculated based on the mean kinship matrix was 0.862 and the population mean kinship was 0.138. The founder genome equivalent based on the mean kinship matrix was 3.61; the founder genome surviving level was 12.34; the mean Ne was estimated at 21.76; and the Ne/N ratio was 0.135. The FIS inbreeding coefficient for 21 STR was negative, and the mean FIS value for all loci had a low negative value (−0.018). These values suggest a low level of inbreeding in the examined breed as well as the avoidance of mating related animals.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Salvatore Bordonaro ◽  
Anna Maria Guastella ◽  
Andrea Criscione ◽  
Antonio Zuccaro ◽  
Donata Marletta

The genetic variability of Pantesco and other two Sicilian autochthonous donkey breeds (Ragusano and Grigio Siciliano) was assessed using a set of 14 microsatellites. The main goals were to describe the current differentiation among the breeds and to provide genetic information useful to safeguard the Pantesco breed as well as to manage Ragusano and Grigio Siciliano. In the whole sample, that included 108 donkeys representative of the three populations, a total of 85 alleles were detected. The mean number of alleles was lower in Pantesco (3.7), than in Grigio Siciliano and Ragusano (4.4 and 5.9, resp.). The three breeds showed a quite low level of gene diversity (He) ranging from 0.471 in Pantesco to 0.589 in Grigio. The overall genetic differentiation index (Fst) was quite high; more than 10% of the diversity was found among breeds. Reynolds’ () genetic distances, correspondence, and population structure analysis reproduced the same picture, revealing that, (a) Pantesco breed is the most differentiated in the context of the Sicilian indigenous breeds, (b) within Ragusano breed, two well-defined subgroups were observed. This information is worth of further investigation in order to provide suitable data for conservation strategies.


2011 ◽  
Vol 60 (1) ◽  
pp. 79-84
Author(s):  
Katarzyna Wąsowicz ◽  
Monika Szczecińska ◽  
Jakub Sawicki

The reasons for low intrapopulation genetic variation in Lamium incisum Willd The paper presents results of a study which aim was preliminary screening of intrapopulation genetic variability in Lamium incisum Willd. This weed species is rarely distributed in Poland and lessening its count during the last years. As a plant inhabiting anthropogenic sites it is exposed to extreme conditions and disturbances caused mostly by the progressive intensification of agriculture. In order to investigate the genetic variability of the selected population markers of ISSR category were used. The analysis of chosen individuals with use of three ISSR primers revealed total of 49 loci, of which only 15 were polymorphic. Nei's gene diversity index (HE=0.099) and the mean number of alleles per locus (AE=1.160) indicated low genetic diversity within the examined population. The research presented in this paper allows for a better learning of the genetic variability of the investigated species and considers probable factors influencing its level.


Genome ◽  
1995 ◽  
Vol 38 (5) ◽  
pp. 879-888 ◽  
Author(s):  
Malika Ainouche ◽  
Marie-Thérèse Misset ◽  
André Huon

The levels of genetic diversity assessed from allozyme data were investigated in 25 populations of Mediterranean Bromus intermedius, B. squarrosus, B. lanceolatus, and B. hordeaceus from Algeria. The geographically restricted diploids B. intermedius and B. squarrosus displayed less genetic diversity (the mean population gene diversity of Nei (Hu) ranged from 0.03 to 0.12) than the widespread tetraploid colonizers B. lanceolatus and B. hordeaceus (Hu = 0.07–0.27). Deviations from Hardy–Weinberg expectations in diploid populations of B. intermedius and B. squarrosus were observed owing to heterozygote excess at several loci and suggested that these self-fertilizing species may have substantial amounts of allogamy. Tetraploid populations of B. lanceolatus and B. hordeaceus were largely homozygous at homologous loci and frequently exhibited intergenomic fixed heterozygosity in accordance with their alloploid origin. Genetic variation at the infraspecific level was mostly distributed within populations in the four species, B. hordeaceus showing the lowest level of interpopulation differentiation (Gst = 0.06) and the highest level of gene flow (Nm = 3.75). Consistent gene flows are in agreement with the strongest intercontinental invasive behaviour of B. hordeaceus. Less differentiation was reported in the literature among later introduced B. hordeaceus populations from England and Australia, indicating reduced differentiation under the process of colonization. Moderate divergence occured among the four taxa, with interspecific genetic identities ranging from 0.87 to 0.93. In spite of substantial genetic similarity, species were clearly differentiated, with each tetraploid being more closely related to a diploid: B. hordeaceus to B. squarrosus and B. lanceolatus to B. intermedius.Key words: Bromus, enzyme electrophoresis, population genetics, colonizing abilities, allopolyploidy.


2010 ◽  
Vol 90 (5) ◽  
pp. 755-765 ◽  
Author(s):  
M. T. Tesfaendrias ◽  
M. R. McDonald ◽  
J. Warland

To identify carrot and onion cultivars that provide consistent marketable yields, we tracked the yields of five fresh market carrot [(Daucus carota L. subsp. sativus (Hoffm.) Arcang.] and six onion (Allium cepa L.) cultivars for at least 13 yr. Relationships between long-term weather variables and marketable yields were also investigated. The effects of cultivar, year and cultivar × year interactions on yield of carrots and onions were assessed. Cultivar and year had significant effects on carrot and onion yields, while the interaction was significant in only one of four data sets of carrot yield. Carrot cv. Cellobunch (95.4 t ha–1) and onion cv. Corona (74.1 t ha–1) had the highest mean marketable yields over the years studied. There was a slight positive correlation between mean yield of the assessed carrots and maximum temperatures in September (r = 0.44). Mean carrot yield was also somewhat negatively correlated with total rainfall in July (r = –0.43) and with number of days with rain in August (r = –0.43) and September (r = –0.44). Most onion cultivars showed stronger relationships between marketable yield and various weather patterns. Marketable yield of onions increased with an increase in the number of days with rainfall in June (r = 0.57). The mean marketable yield of the six onion cultivars decreased in relation to temperatures ≥30°C in June (r = –0.55) and August (r = –0.53). The mean yield of all the onions in the trials was negatively correlated (r = –0.78) with growing degree days (base 5°C, May to August). The results indicated that the data from long-term cultivar trials can be used to identify cultivars that yield well despite seasonal variations in weather. Key words: Daucus carota, Allium cepa, temperature, rainfall


2021 ◽  
Vol 43 (1) ◽  
pp. 38-42
Author(s):  
Kavungal Priya ◽  
◽  
Indira . ◽  
Vadakkethil Balakrishnan Sreekumar ◽  
Renuka . ◽  
...  

Calamus brandisii Becc. is one of the endemic slender rattans found in the Western Ghats of India. The genetic diversity of two main populations available in Kerala was investigated using 20 RAPD and 9 ISSR markers. Two parameters viz., gene diversity and genetic diversity within and among populations were analyzed. ISSR analysis showed quite high genetic diversity in Pandimotta compared to Bonacaud population whereas in RAPD markers both these populations were moderately diverse. The percentage of total genetic differentiation (Gst) among two populations is relatively higher than the mean Gst value indicating high genetic diversity within the populations. The genetic distance between these two populations was 0.1739 with ISSR markers and 0.1971 with RAPD markers. Because of its high genetic diversity, Pandimotta population can be treated as an important population of gene diversity with potentially useful genes. This may be included in the high priority reservoir for genetic conservation also.


2000 ◽  
Vol 23 (1) ◽  
pp. 229-234 ◽  
Author(s):  
José Marcelo Soriano Viana ◽  
Cosme Damião Cruz ◽  
Antonio Américo Cardoso ◽  
Adair José Regazzi

The theory of variance analysis of partial diallel tables, following Hayman's proposal of 1954, is presented. As several statistical tests yield similar inferences, the present analysis mainly proposes to assess genetic variability in two groups of parents and to study specific, varietal and mean heteroses. Testing the nullity of specific heteroses equals testing absence of dominance. Testing equality of varietal heteroses of the parents of a group is equivalent to testing the hypothesis that in the other group allelic genes have the same frequency. Rejection of the hypothesis that the mean heterosis is null indicates dominance. The information obtained complements that provided by diallel analysis involving parents and their F1 hybrids or F2 generations. An example with the common bean is included.


Genetics ◽  
1977 ◽  
Vol 86 (3) ◽  
pp. 697-713
Author(s):  
C Chevalet ◽  
M Gillois ◽  
R F Nassar

ABSTRACT Properties of identity relation between genes are discussed, and a derivation of recurrent equations of identity coefficients in a random mating, diploid dioecious population is presented. Computations are run by repeated matrix multiplication. Results show that for effective population size (Ne) larger than 16 and no mutation, a given identity coefficient at any time t can be expressed approximately as a function of (1—f), (1—f)3 and (1—f)6, where f is the mean inbreeding coefficient at time t. Tables are presented, for small Ne values and extreme sex ratios, showing the pattern of change in the identity coefficients over time. The pattern of evolution of identity coefficients is also presented and discussed with respect to N eu, where u is the mutation rate. Applications of these results to the evolution of genetic variability within and between inbred lines are discussed.


1990 ◽  
Vol 115 (3) ◽  
pp. 509-512 ◽  
Author(s):  
Geok Yong Tan

Six Trinitario females of cacao (Theobroma cacao L.) were crossed with nine Amazonian males in a factorial crossing design. The 54 hybrid progenies were used to estimate genetic variability due to general combining ability (GCA) and specific combining ability (SCA) for yield, pod production, pod weight, husk content, number of beans per pod, average bean weight, and pod value. The results demonstrated that GCA differed significantly for all characteristics from all three sources (Le., female + male, female, and male). SCA (female × male) was also significantly different for all characteristics. The ratio of GCA to SCA ranged from 7.1 for number of beans per pod to 25.7 for pod weight. This result suggested that a major portion of the genetic variability was additive in nature for these characteristics. Among the six Trinitarios, KA2-106 was the best female parent; it contributed high yield and all the desirable pod and bean characteristics into the hybrid progenies. Trinitario KA2-101 combined high pod production and yield, but tended to transmit below-average pod and bean characteristics to its progenies. Amazonians KEE6 and KEE12 were the two highest-yielding male parents, but had below-average bean number per pod and average bean weight. KEE42 and KEE43 combined high yield and transmitted good pod and bean characteristics to their progenies. Based on the GCA effects and the mean performance of the hybrid progenies, a multi-line cultivar consisting of 20 high-yielding crosses with good pod and bean characteristics is being produced in seed gardens for commercial planting.


2016 ◽  
Vol 42 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Katarzyna Buczkowska ◽  
Alina Bączkiewicz ◽  
Patrycja Gonera

Abstract Calypogeia azurea, a widespread, subboreal-montane liverwort species, is one of a few representatives of the Calypogeia genus that are characterized by the occurrence of blue oil bodies. The aim of the study was to investigate the genetic variation and population structure of C. azurea originating from different parts of its distribution range (Europe and North America). Plants of C. azurea were compared with C. peruviana, another Calypogeia species with blue oil bodies. In general, 339 gametophytes from 15 populations of C. azurea were examined. Total gene diversity (HT) estimated on the basis of nine isozyme loci of C. azurea at the species level was 0.201. The mean Nei’s genetic distance between European populations was equal to 0.083, whereas the mean genetic distance between populations originating from Europe and North America was 0.413. The analysis of molecular variance (AMOVA) showed that 69% of C. azurea genetic variation was distributed among regions (Europe and North America), 15% - among populations within regions, and 16% - within populations. Our study revealed that C. azurea showed genetic diversity within its geographic distribution. All examined samples classified as C. azurea differed in respect of isozyme patterns from C. peruviana.


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