scholarly journals Can Knowledge of Genetic Distances, Genome Sizes and Chromosome Numbers Support Breeding Programs in Hardy Geraniums?

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 730
Author(s):  
Mehrdad Akbarzadeh ◽  
Katrijn Van Laere ◽  
Leen Leus ◽  
Jan De Riek ◽  
Johan Van Huylenbroeck ◽  
...  

Breeding programs in ornamentals can be facilitated by integrating knowledge of phylogenetic relatedness of potential parents along with other genomic information. Using AFLP, genetic distances were determined for 59 Geranium genotypes, comprising 55 commercial cultivars of the three subgenera of a total collection of 61 Geranium genotypes. A subgroup of 45 genotypes, including intragroup and intergroup hybrids, were selected and further characterized for genome sizes and chromosome numbers. The variation in genome size ranged from 1.51 ± 0.01 pg/2C to 12.94 ± 0.07 pg/2C. The chromosome numbers ranged from 26 to 108–110 with some hybrids showing an aberrant number of chromosomes based on their parents’ constitution. All chromosome numbers of Geranium are an even number, which presumes that unreduced gametes occur in some cross combinations. Overall, parental difference in genome size and chromosome number were not limiting for cross compatibility. Good crossing compatibility was correlated to a Jaccard similarity coefficient as parameter for parental relatedness of about 0.5. Additionally, parent combinations with high differences in the DNA/chromosome value could not result in a successful cross. We expect that our results will enable breeding programs to overcome crossing barriers and support further breeding initiatives.

Genetika ◽  
2021 ◽  
Vol 53 (2) ◽  
pp. 883-894
Author(s):  
Xinxin Zhang ◽  
Abdul Shakoor

Species identification is fundamentally important within the fields of biology, biogeography, ecology and conservation. The genus Paracaryum belongs to tribe Cynoglosseae of the family Boraginaceae is a herbaceous genus including approximately 67 species, mostly distributed in the Irano-Turanian phytogeographical region. In spite vast distribution of many Paracaryum species that grow in different habitats, there are not any available report on their genetic diversity, mode of divergence and patterns of dispersal. Therefore, we performed molecular (ISSR markers) of 98 accessions from 12 species of Paracaryum that were collected from different habitats. A set of 10 ISSR markers was used. The genetic distances were estimated based on Jaccard similarity coefficient and the descriptive statistics of populations for estimation of genetic parameters were also performed. A total of 90 polymorphic bands were obtained. The present study revealed that ISSR data can delimit the species. AMOVA and STRUCTURE analysis revealed that the species of Paracaryum belongs are genetically differentiated but have some degree of shared common alleles.


HortScience ◽  
2011 ◽  
Vol 46 (4) ◽  
pp. 567-570 ◽  
Author(s):  
Ryan N. Contreras ◽  
John M. Ruter

Genome size estimates and chromosome number information can be useful for studying the evolution or taxonomy of a group and also can be useful for plant breeders in predicting cross-compatibility. Callicarpa L. is a group of ≈140 species with nearly worldwide distribution. There are no estimates of genome size in the literature and the information on chromosome numbers is limited. Genome size estimates based on flow cytometry are reported here for 16 accessions of Callicarpa comprising 14 species in addition to chromosome counts on six species. Chromosome counts were conducted by staining meristematic cells of roots tips using modified carbol fuchsin. Holoploid genome size estimates ranged from 1.34 pg to 3.48 pg with a mean of 1.74 pg. Two tetraploids (2n = 4x = 68; C. salicifolia P'ei & W. Z. Fang and C. macrophylla Vahl GEN09-0081) were identified based on holoploid genome size and confirmed by chromosome counts. There was little variation among species for monoploid genome size. 1Cx-values ranged from 0.67 pg to 0.88 pg with a mean of 0.77 pg. Chromosome counts for six species revealed a base chromosome number of x = 17. Callicarpa chejuensis Y. H. Chung & H. Kim, C. japonica Thunb. ‘Leucocarpa’, C. longissima Merr., and C. rubella Lindl. were confirmed as diploids (2n = 2x = 34). Cytology supported flow cytometry data that C. salicifolia and C. macrophylla GEN09-0081 were tetraploids. The two accessions of C. macrophylla included in the study were found to be of different ploidy levels. The presence of two ploidy levels among and within species indicates that polyploidization events have occurred in the genus.


Author(s):  
Rezq Basheer-Salimia

Abstract: In Palestine, grape culture consists of ecotypes and cultivars (also called local varieties), for which a large number of homonymous and synonymous designations exist as well as misnaming of cultivars. The present study is the first report using detailed ampelographic characterizations (39 informative traits) to assess genetic diversity and detect similarities among sixteen accessions collected from putative diverse grape genotypes In general, 30 descriptors presented highly and satisfactory divergent genotypes, whereas the remaining traits showed no or very little ampelographic variation. Based on the similarity matrix and the resulting dendrogram of these ampelographic data, distinguishable genotypes as well as some cases of synonymies and homonymies clearly exist. A synonymy case seemed to be in four genotypes including Jandali-Mfarad, Jan-dali-Mrazraz, Jandali, and Hamadani-Mattar, which indeed showed genetic distances of less than 0.5, sug-gesting their relatedness, and the possibility that they are the same genotype, but with different names. In addition, homonym cases also occur in the following pairs of “Marawi’s, Hamadani’s, and Zaini’s genotypes, in which each pair seems to be two distinctive genotypes. Finally, among the 16 examined genotypes, the Zaini-Baladi genotype tended to show the highest genetic distance values from the others and thus could be potentially incorporated into any further local or regional breeding programs as well as germplasm conservation.


2005 ◽  
Vol 40 (10) ◽  
pp. 975-980 ◽  
Author(s):  
Maria Imaculada Zucchi ◽  
José Baldin Pinheiro ◽  
Lázaro José Chaves ◽  
Alexandre Siqueira Guedes Coelho ◽  
Mansuêmia Alves Couto ◽  
...  

This study was carried out to assess the genetic variability of ten "cagaita" tree (Eugenia dysenterica) populations in Southeastern Goiás. Fifty-four randomly amplified polymorphic DNA (RAPD) loci were used to characterize the population genetic variability, using the analysis of molecular variance (AMOVA). A phiST value of 0.2703 was obtained, showing that 27.03% and 72.97% of the genetic variability is present among and within populations, respectively. The Pearson correlation coefficient (r) among the genetic distances matrix (1 - Jaccard similarity index) and the geographic distances were estimated, and a strong positive correlation was detected. Results suggest that these populations are differentiating through a stochastic process, with restricted and geographic distribution dependent gene flow.


Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1436
Author(s):  
Magdalena Senderowicz ◽  
Teresa Nowak ◽  
Magdalena Rojek-Jelonek ◽  
Maciej Bisaga ◽  
Laszlo Papp ◽  
...  

The evolution of the karyotype and genome size was examined in species of Crepis sensu lato. The phylogenetic relationships, inferred from the plastid and nrITS DNA sequences, were used as a framework to infer the patterns of karyotype evolution. Five different base chromosome numbers (x = 3, 4, 5, 6, and 11) were observed. A phylogenetic analysis of the evolution of the chromosome numbers allowed the inference of x = 6 as the ancestral state and the descending dysploidy as the major direction of the chromosome base number evolution. The derived base chromosome numbers (x = 5, 4, and 3) were found to have originated independently and recurrently in the different lineages of the genus. A few independent events of increases in karyotype asymmetry were inferred to have accompanied the karyotype evolution in Crepis. The genome sizes of 33 Crepis species differed seven-fold and the ancestral genome size was reconstructed to be 1 C = 3.44 pg. Both decreases and increases in the genome size were inferred to have occurred within and between the lineages. The data suggest that, in addition to dysploidy, the amplification/elimination of various repetitive DNAs was likely involved in the genome and taxa differentiation in the genus.


HortScience ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 275-282 ◽  
Author(s):  
Saadat Sarikhani Khorami ◽  
Kazem Arzani ◽  
Ghasem Karimzadeh ◽  
Abdolali Shojaeiyan ◽  
Wilco Ligterink

Plant genetic diversity is the fundamental of plant-breeding programs to improve desirable characteristics. Hence, evaluation of genetic diversity is the first step in fruit-breeding programs. Accordingly, the current study was carried out to evaluate 25 superior walnut genotypes in respect of phenotypic and cytological characteristics. For this purpose, 560 walnut genotypes in southwest of Iran were evaluated based on UPOV and International Plant Genetic Resources Institute (IPGRI) descriptor. After a 2-year primary evaluation, 25 superior genotypes were selected for future phenotypic and genome size assessment. Flow cytometry was used to estimate genome size of the selected superior genotypes. A high genetic diversity was found in walnut population collected from the southwest of Iran. The selected superior genotypes had high yield, lateral bearing, thin-shell thickness (0.90–1.64 mm), high nut (12.54–19.80 g) and kernel (7.02–9.91 g) weight with light (L) to extra light (EL) kernel color which easily can be removed from the shell. Also, FaBaCh2 genotype turned out to be protogynous being important as a pollinizer cultivar. In addition to extensive phenotypic analysis, genome size was determined. The studied genotypes were diploid (2n = 2x = 32) and varied in genome size from 1.29 (FaBaAv2) to 1.40 pg (FaBaNs12). Correlation analysis showed that lateral bearing, budbreak date, nut size, and weight were the main variables contributing to walnut production. A linear relationship was found between genome size and nut weight (r = 0.527**), kernel weight (r = 0.551**), and nut size index (NSI) (r = 0.487**). Therefore, genome size can be considered as a strong and valuable tool to predict nut and kernel weight and nut size.


HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 620-623
Author(s):  
Thomas G. Ranney ◽  
Connor F. Ryan ◽  
Lauren E. Deans ◽  
Nathan P. Lynch

Illicium is an ancient genus and member of the earliest diverging angiosperms known as the Amborellales, Nymphaeales, and Austrobaileyales (ANA) grade. These adaptable, broadleaf evergreen shrubs, including ≈40 species distributed throughout Asia and North America, are valued for diverse culinary, medicinal, and ornamental applications. The study of cytogenetics of Illicium can clarify various discrepancies and further elucidate chromosome numbers, ploidy, and chromosome and genome size evolution in this basal angiosperm lineage and provide basic information to guide plant breeding and improvement programs. The objectives of this study were to use flow cytometry and traditional cytology to determine chromosome numbers, ploidy levels, and relative genome sizes of cultivated Illicium. Of the 29 taxa sampled, including ≈11 species and one hybrid, 2C DNA contents ranged from 24.5 pg for Illicium lanceolatum to 27.9 pg for Illicium aff. majus. The genome sizes of Illicium species are considerably higher than other ANA grade lineages indicating that Illicium went through considerable genome expansion compared with sister lineages. The New World sect. Cymbostemon had a slightly lower mean 2C genome size of 25.1 pg compared with the Old World sect. Illicium at 25.9 pg, providing further support for recognizing these taxonomic sections. All taxa appeared to be diploid and 2n = 2x = 28, except for Illicium floridanum and Illicium mexicanum which were found to be 2n = 2x = 26, most likely resulting from dysploid reduction after divergence into North America. The base chromosome number of x = 14 for most Illicium species suggests that Illicium are ancient paleotetraploids that underwent a whole genome duplication derived from an ancestral base of x = 7. Information on cytogenetics, coupled with phylogenetic analyses, identifies some limitations, but also considerable potential for the development of plant breeding and improvement programs with this genus.


Author(s):  
Huaqi Zhang ◽  
Guanglei Wang ◽  
Yan Li ◽  
Feng Lin ◽  
Yechen Han ◽  
...  

Coronary optical coherence tomography (OCT) is a new high-resolution intravascular imaging technology that clearly depicts coronary artery stenosis and plaque information. Study of coronary OCT images is of significance in the diagnosis of coronary atherosclerotic heart disease (CAD). We introduce a new method based on the convolutional neural network (CNN) and an improved random walk (RW) algorithm for the recognition and segmentation of calcified, lipid and fibrotic plaque in coronary OCT images. First, we design CNN with three different depths (2, 4 or 6 convolutional layers) to perform the automatic recognition and select the optimal CNN model. Then, we device an improved RW algorithm. According to the gray-level distribution characteristics of coronary OCT images, the weights of intensity and texture term in the weight function of RW algorithm are adjusted by an adaptive weight. Finally, we apply mathematical morphology in combination with two RWs to accurately segment the plaque area. Compared with the ground truth of clinical segmentation results, the Jaccard similarity coefficient (JSC) of calcified and lipid plaque segmentation results is 0.864, the average symmetric contour distance (ASCD) is 0.375[Formula: see text]mm, the JSC and ASCD reliabilities are 88.33% and 92.50% respectively. The JSC of fibrotic plaque is 0.876, the ASCD is 0.349[Formula: see text]mm, the JSC and ASCD reliabilities are 90.83% and 95.83% respectively. In addition, the average segmentation time (AST) does not exceed 5 s. Reliable and significantly improved results have been achieved in this study. Compared with the CNN, traditional RW algorithm and other methods. The proposed method has the advantages of fast segmentation, high accuracy and reliability, and holds promise as an aid to doctors in the diagnosis of CAD.


2015 ◽  
Vol 08 (05) ◽  
pp. 1550070 ◽  
Author(s):  
Lan-Ying Zhou ◽  
Xiang-Nan Wang ◽  
Li-Ping Wang ◽  
Yong-Zhong Chen ◽  
Xiao-Cheng Jiang

Genetic diversity of 51 oil-tea camellia germplasms was analyzed using the optimized inter-simple sequence repeat (ISSR)–PCR reaction system with 22 primers screened from a set of 100 ISSR primers. The results showed that 493 discernible loci with distinct electrophoretic bands were obtained, of which, 478 loci (96.78%) were polymorphic. This indicated that oil-tea germplasms possess abundant genetic diversities. By clustering analysis performed using softwares of NTSYS 2.10 and Winboot, 51 oil-tea germplasms were divided into two groups: Group I had 48 lines of Camellia oleifera Abel, while Group II had three C. oleifera Abel related species and their similarity coefficient was 0.62. Group I was further divided into Group I-1 and Group I-2, and their similarity coefficient (Gs) was 0.634. All members of Group I-1 originated from Hunan Province, while Group I-2 included the rest of Hunan lines and those originated from other regions of China. Analyzed by software POPGENE 1.32, the Shannon's information index (I*) of genetic polymorphism was 0.3852, the genetic diversity among different region populations (Ht) was 0.2537, the genetic diversity within populations (Hs) was 0.15545, the differentiation coefficient of genetic diversity among populations (Gst) was 0.3967, and the gene flow among populations (Nm*) was 0.8262. The Nei's genetic distances between the Hunan population and the populations originated from other regions of China implied that geographic isolation strongly influenced genetic differentiation among populations. Meanwhile, seedling rootstock grafting and high grafting for tree crown produced genetic variations among clonal offsprings.


2014 ◽  
Vol 175 (9) ◽  
pp. 986-997 ◽  
Author(s):  
Root Gorelick ◽  
Danielle Fraser ◽  
Ben J. M. Zonneveld ◽  
Damon P. Little

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