scholarly journals Are there differences in heterozygosity of strains obtained from intercrossed and self-fertilized onion plants?

2020 ◽  
Vol 38 (3) ◽  
pp. 274-279
Author(s):  
José Magno Queiroz Luz ◽  
Daniel Lucas Magalhães Machado ◽  
Gabriel Mascarenhas Maciel ◽  
Joelson André de Freitas ◽  
Roberta Camargos de Oliveira
Keyword(s):  
Ssr Markers ◽  
Inbreeding Depression ◽  
Breeding Program ◽  
Germplasm Characterization ◽  
Microsatellite Primers ◽  
Commercial Use ◽  
Self Fertilization ◽  
Characterization Studies ◽  
Per Se ◽  
The Cross

ABSTRACT The commercial use of onion hybrids is preferred by producers. In contrast, the production of hybrid onion seeds is extremely inefficient. This is due to the use of lineages obtained by successive self-fertilizations assuming the effect of inbreeding depression per se. Therefore, it is necessary to understand new alternatives to reduce the effect of inbreeding depression in the strains. The objective of this study was to evaluate possible differences in polymorphism and levels of heterozygosity of strains obtained from intercrossed and self-fertilized plants. Twelve onion populations belonging to Bayer’s breeding program (Granex, IPA-1, IPA-2 and IPA-3) were used, obtained by self-fertilization of one plant, intercrossing of two plants or intercrossing of three plants. Three individuals from each strain were used in the analyzes. The amplifications were performed using 8 microsatellite primers with greater polymorphism, according to germplasm characterization studies carried out by CITA. Heterozygosity generally decreases with self-fertilization and increases as more plants are used in the cross. The SSR markers used in the present study were efficient in detecting variability in different genetic backgrounds. With the results obtained, it is suggested to carry out the obtaining of hybrids between the different combinations and to analyze the performance per se of the different modalities of obtaining strains proposed in the present research.

Genetic divergence studies through microsatellite markers in pigeonpea [Cajanus cajan (L) Millsp.]

2018 ◽  
Author(s):  
Pankaj Sharma ◽  
Inderjit Singh ◽  
Asmita Sirari ◽  
Sarvjeet Singh ◽  
Gaurav Khosla
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Cajanus Cajan ◽  
Polymorphic Information Content ◽  
Germplasm Characterization ◽  
Male Sterile ◽  
Dissimilarity Coefficient ◽  
Improvement Programs ◽  
Characterization Studies ◽  
Simple Sequence

The Genetic diversity was assessed among 96 pigeonpea accessions including 15 male sterile, 13 maintainer and 68 germplasm lines using 44 Simple Sequence Repeats (SSR) markers distributed over all the 11 chromosomes. Out of 44 SSR markers, 33 were polymorphic which showed 75% polymorphism among the used markers. For an individual primer, the alleles amplified varied from 2 to 4 with an average of 2.54. The Polymorphic Information Content (PIC) values ranged from 0.26 (CCM 0183) to 0.78 (CCM 0402 and CCM 0721). Based on 112 alleles amplified by SSR markers, the 96 genotypes were alienated into eight clusters. Cluster I and cluster VII were the largest with 22 genotypes each, cluster III and cluster IV were the smallest with two genotypes each, while cluster II, cluster V, cluster VI and cluster VIII consisted of 10, 15, 14 and 9 genotypes, respectively. Genotypes Pusa 991 and ULA 11 were found to be the most distant genotypes with highest dissimilarity coefficient (32%) where as AL 112A and AL 113A were the least distant genotypes with lowest dissimilarity coefficient (2%). Thus, highly distant genotypes can be used in pigeonpea improvement programs for getting desirable segregants. The selected panel of polymorphic SSR markers performed well in detection of genetic diversity patterns and can be used for future germplasm characterization studies in pigeonpea.

scholarly journals EVALUATION OF GENETIC DIVERSITY IN CACAO COLLECTED FROM KOLAKA, SOUTHEAST SULAWESI, USING SSR MARKERS

2016 ◽  
Vol 16 (2) ◽  
pp. 71
Author(s):  
Rubiyo Rubiyo ◽  
Nur Kholilatul Izzah ◽  
Indah Sulistiyorini ◽  
Cici Tresniawati
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Gel Electrophoresis ◽  
Genetic Similarity ◽  
Similarity Coefficient ◽  
Breeding Program ◽  
New Variety ◽  
Average Value ◽  
The Third ◽  
Ctab Method

Kolaka, which is located in Southeast Sulawesi, has long been known as one of cacao production centers in Indonesia. Therefore, many different cacao germplasms can be found in this region. The study aimed to evaluate genetic diversity and relationships of 12 cacao genotypes collected from Kolaka. Genomic DNA was extracted by using a modified CTAB method. Meanwhile, genetic diversity was analyzed based on 16 SSR markers, which then separated by 6% non-denaturing polyacryl-amide gel electrophoresis. The result showed that all of those markers, 14 markers exhibited polymorphism and subsequently used for data analysis using NTSYS and PowerMarker program. About 70 different alleles were generated from 12 cacao genotypes analyzed with an average of 5 alleles per locus. Average value of polymorphism information content (PIC) resulted in this study was 0.59. The cluster analysis using UPGMA method based on the genetic similarity coefficient revealed that all cacao genotypes were separated into three major groups. The first group consisted of five cacao genotypes, the second one held four cacao genotypes, whereas the third group contained three genotypes. This result indicates that three genotypes that clustered separately from the others could be used as a good clonal candidate for cacao breeding program. The information resulted from this present study would be useful for future cacao breeding program, especially in efforts to release a new variety.

Transfer of simple sequence repeat (SSR) markers across the legume family for germplasm characterization and evaluation

2004 ◽  
Vol 2 (2) ◽  
pp. 107-119 ◽  
Author(s):  
M. L. Wang ◽  
A. G. Gillaspie ◽  
M. L. Newman ◽  
R. E. Dean ◽  
R. N. Pittman ◽  
...  
Keyword(s):  
Ssr Markers ◽  
Simple Sequence Repeat ◽  
Germplasm Characterization ◽  
Sequence Repeat ◽  
Simple Sequence

scholarly journals Epistasis, inbreeding depression, and the evolution of self‐fertilization

Evolution ◽  
2020 ◽  
Vol 74 (7) ◽  
pp. 1301-1320
Author(s):  
Diala Abu Awad ◽  
Denis Roze
Keyword(s):  
Inbreeding Depression ◽  
Self Fertilization

scholarly journals Agronomical and molecular characterization of banana germplasm

2010 ◽  
Vol 45 (2) ◽  
pp. 146-154 ◽  
Author(s):  
Lorenna Alves Mattos ◽  
Edson Perito Amorim ◽  
Vanusia Batista de Oliveira Amorim ◽  
Kelly de Oliveira Cohen ◽  
Carlos Alberto da Silva Ledo ◽  
...  
Keyword(s):  
Ssr Markers ◽  
Physicochemical Characteristics ◽  
High Variability ◽  
Microsatellite Primers ◽  
Germplasm Bank ◽  
B Genome ◽  
Agronomical Traits ◽  
Simple Sequence ◽  
Agronomical Characters

The objective of the present work was to characterize banana accessions from the Germplasm Bank at Embrapa Mandioca e Fruticultura Tropical (Brazil), using agronomical, physical and physicochemical characteristics of fruit and simple sequence repeats (SSR) markers. Twenty-six accessions were analyzed, in which high genetic variability was found, especially for the agronomical characters number of fruit and weight of bunch. Accessions with high contents of carotenoids (diploid 'Jaran'), polyphenols (triploid 'Caipira' and tetraploid 'Teparod') and vitamin C (diploid 'Tuugia' and an unknown triploid AAA) in the fruit were identified. Thirteen microsatellite primers revealed an average of 7.23 alleles, which showed high variability. A dendrogram was prepared using the Gower algorithm for the distance matrices obtained from the agronomical, physical and physicolchemical analysis of fruit and SSR markers. Adopting the average genetic divergence as the cut-off point, three clusters were found: G1, formed by the diploids 'Jaran', 028003-01 and M-48; G2, by the diploids 'Malbut' and 'Ido 110'; and G3, by 21 tri-and tetraploid accessions, including one diploid, 'Tuugia'. The triploids with the B genome 'Thap Maeo', 'Walha', 'Pacha Nadan' and 'Champa Madras' were grouped in G2. Results from this work can be used for breeding hybrids with good agronomical traits and fruit quality.

THREE GENERATIONS OF INBREEDING AND S2 FACTORIAL TEST CROSSES IN RED RASPBERRY CULTIVARS

1974 ◽  
Vol 16 (2) ◽  
pp. 419-432 ◽  
Author(s):  
S. O. Fejer ◽  
L. P. S. Spangelo
Keyword(s):  
Plant Height ◽  
Inbreeding Depression ◽  
Breeding Program ◽  
High Yield ◽  
Realized Heritability ◽  
Red Raspberry ◽  
Diallel Crosses ◽  
Berry Quality ◽  
Selection For ◽  
Early Vigor

In selfed (S1 to 33) progenies of red raspberry cultivars, inbreeding depression progressively reduced plant height in spite of selection for vigor. Parent-offspring correlations indicated high realized heritability of this character. High yield was correlated in this material with many laterals, early flowering, tall new canes, and good berry quality but not with winter resistance. Heritability in the broad sense was high for early vigor, plant height and winter resistance, lower for berry weight and flowering day, and very low for yield and its morphological components, but selection for vigor may have influenced these estimates.In a second experiment five S2 progenies and their parent cultivars Muskoka, Trent and Tweed were crossed with three tester plants, Ottawa Latham, Viking and 45-01-56. Some of the S2 × tester progenies were superior in a number of yield characters to those produced when their parent cultivar was crossed to the same testers. The results were similar to those with strawberry (Spangelo et al., 1971), suggesting that inbreeding may sometimes be a useful step in a raspberry breeding program for higher yield. However, inbred × inbred crosses were generally poor. General and specific combining abilities were mostly similar in three different samples of factorial ("¼ diallel") crosses, but there were many exceptions possibly due to genotype-environment interactions. Most of the correlations were significant in this trial and the highest ones were in agreement with the correlations in the inbreeding trial.

A potential solution to the chromosome instability problem in hexaploid alfalfa, Medicago sativa L.

Genome ◽  
1989 ◽  
Vol 32 (2) ◽  
pp. 302-306 ◽  
Author(s):  
T. J. McCoy
Keyword(s):  
Medicago Sativa ◽  
Interspecific Hybrids ◽  
Chromosome Instability ◽  
Chromosome Stability ◽  
Potential Solution ◽  
Chromosome Counts ◽  
Instability Problem ◽  
Commercial Use ◽  
Medicago Sativa L ◽  
The Cross

Autohexaploid alfalfa (2n = 6x = 48) is chromosomally unstable, which prevents commercial use. The objective of this investigation was to test whether synthesizing Medicago hexaploids (2n = 6x = 48) that are alloautohexaploids results in chromosomally stable hexaploid populations. Previous research in our laboratory demonstrated a lack of affinity between the genomes of alfalfa and M. papillosa Boiss. Triploid (2n = 3x = 24) interspecific hybrids with two M. papillosa genomes and one genome of M. sativa were readily recovered from seed following the cross (2x) M. sativa × (4x) M. papillosa. For this study, the triploids were chromosomally doubled to produce alloautohexaploids, and these alloautohexaploids were used to test chromosome stability in hexaploids with no more than four homologous genomes. Chromosome counts of 47 progeny from intercrossing the alloautohexaploids demonstrated all were hexaploid, indicating chromosome stability. Designing novel genomic combinations based on genomic affinity may result in higher yielding alfalfa populations that have a modified cytogenetic structure.Key words: Medicago cancellata, Medicago papillosa, Medicago saxatilis, genomic affinity, hexaploids.

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