Cytological and molecular analysis of annual species of the genus Medicago

1996 ◽  
Vol 74 (2) ◽  
pp. 299-307 ◽  
Author(s):  
A. Mariani ◽  
F. Pupilli ◽  
O. Calderini
Keyword(s):  
Chromosome Number ◽  
Molecular Analysis ◽  
Genetic Relationship ◽  
Diploid Species ◽  
Rflp Analysis ◽  
Molecular Study ◽  
Annual Species ◽  
Genetic Affinity ◽  
Karyological Analysis ◽  
Medicago Rugosa

Medicago rugosa and M. scutellata, two annual species of the genus Medicago, have aroused considerable interest because they carry useful traits that could be introduced into alfalfa and have a chromosome number (2n = 30) that is quite unusual in Medicago. A cytogenetic and molecular study was undertaken to investigate the annual diploid species with 2n = 16 and 2n = 14 that seem to be the most closely related to M. rugosa and M. scutellata, with the aim of characterizing these diploid species and determining their genetic relationship with the species with 2n = 30. Karyological analysis established that some of the diploid species investigated were more similar than the others to both M. rugosa and M. scutellata (as in the case of M. intertexta, M. rotata, and M. polymorpha) or at least to one of those two species (as was the case with M. doliata, M. muricoleptis, and M. murex). RFLP analysis identified four species, namely M. intertexta and M. muricoleptis with 2n = 16, and M. polymorpha and M. murex with 2n = 14, as having the highest degree of genetic affinity with the two species with 30 chromosomes. These findings suggest the possibility of identifying the ancestors of M. rugosa and M. scutellata among those four species and therefore of verifying the probable allopolyploid origin of the two species in question. Keywords: Medicago, annual species, karyotypes, RFLPs.

On the role of germ cells in planarian regeneration

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 53-63
Author(s):  
V. Gremigni ◽  
C. Miceli ◽  
I. Puccinelli
Keyword(s):  
Chromosome Number ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Karyological Analysis ◽  
Blastema Formation ◽  
Planarian Regeneration ◽  
Somatic Tissues ◽  
Caudal Area ◽  
Complete Regeneration

Specimens from a polyploid biotype of Dugesia lugubris s.l. were used to clarify the role and fate of germ cells during planarian regeneration. These specimens provide a useful karyological marker because embryonic and somatic cells (3n = 12) can be easily distinguished from male (2n = 8) and female (6n = 24) germ cells by their chromosome number. We succeed in demonstrating how primordial germ cells participate in blastema formation and take part in rebuilding somatic tissues. This evidence was obtained by cutting each planarian specimen twice at appropriate levels. The first aimed to induce primordial germ cells to migrate to the wound. The second cut was performed after complete regeneration and aimed to obtain a blastema from a cephalic or caudal area devoid of gonads. A karyological analysis of mitotic cells present in each blastema obtained after the second cut provided evidence that cells, originally belonging to the germ lines, are still present in somatic tissues even months after complete regeneration. The role of primordial germ cells in planarian regeneration was finally discussed in relation to the phenomenon of metaplasia or transdifferentiation.

scholarly journals Relations and evolution in Cheilanthes (Sinopteridaceae, Pteridophita) in Macaronesia and Mediterranean area, deduced from genome analysis of their hybrids

1983 ◽  
Vol 8 ◽  
pp. 101-126 ◽  
Author(s):  
G. Vida ◽  
A. Major ◽  
T. Reichstein
Keyword(s):  
Chromosome Number ◽  
Genome Analysis ◽  
Chromosome Doubling ◽  
Diploid Species ◽  
Mediterranean Area ◽  
Basic Chromosome Number ◽  
The Other ◽  
Experimental Conditions ◽  
Natural Group ◽  
Basic Chromosome

Nine species of "Cheilantoid ferns" are known to grow in Macaronesia and the Mediterranean basin. Two of them (lacking a pseudo-indusium and having the basic chromosome number X = 29), both aggregate species which we prefer to retain in Notholaena, are not included in this study. The other seven species (with distinct pseudo-indusium and the basic chromosome number X = 30), which we accept as members of the genus Cheilanthes Sw. sensu stricto, were subjected to detailed genome analysis of their natural and experimentally produced hybrids and shown to represent an aggregate of four very distinct ancestral diploids and three allotetraploids. The latter must have once been formed by chromosome doubling in the three diploid hybrids of C. maderensis Lowe with the other three diploid species. Theoretically three more allotetraploids would be possible but their formation has obviously been prevented by the geographical separation of the three respective diploids. The most widely distributed of the tetraploids, i.e. C. pteridioides (Reich.) C.Chr. has also been resynthesized from its ancestors (still sympatric) under experimental conditions. The intermediate morphology of the allotetraploids (as compared with their diploid ancestors) is obviously the reason why their status and existence has so long escaped recognition in Europe. These seven species form a natural group and, in our opinion, should not be divided into sections.

Molecular analysis of the genetic relationship of trans interacting factors at the T/t complex

Nature ◽  
1980 ◽  
Vol 288 (5789) ◽  
pp. 368-370 ◽  
Author(s):  
Althea K. Alton ◽  
Lee M. Silver ◽  
Karen Artzt ◽  
Dorothea Bennett
Keyword(s):  
Molecular Analysis ◽  
Genetic Relationship ◽  
T Complex ◽  
Relationship Of

scholarly journals Detection and application of genome-wide variations in peach for association and genetic relationship analysis

BMC Genetics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Liping Guan ◽  
Ke Cao ◽  
Yong Li ◽  
Jian Guo ◽  
Qiang Xu ◽  
...  
Keyword(s):  
Genetic Relationship ◽  
Dna Markers ◽  
High Throughput Sequencing ◽  
Prunus Persica ◽  
Genetic Research ◽  
Diploid Species ◽  
Sequencing Data ◽  
Relationship Analysis ◽  
Genome Wide ◽  
A Genome

Abstract Background Peach (Prunus persica L.) is a diploid species and model plant of the Rosaceae family. In the past decade, significant progress has been made in peach genetic research via DNA markers, but the number of these markers remains limited. Results In this study, we performed a genome-wide DNA markers detection based on sequencing data of six distantly related peach accessions. A total of 650,693~1,053,547 single nucleotide polymorphisms (SNPs), 114,227~178,968 small insertion/deletions (InDels), 8386~12,298 structure variants (SVs), 2111~2581 copy number variants (CNVs) and 229,357~346,940 simple sequence repeats (SSRs) were detected and annotated. To demonstrate the application of DNA markers, 944 SNPs were filtered for association study of fruit ripening time and 15 highly polymorphic SSRs were selected to analyze the genetic relationship among 221 accessions. Conclusions The results showed that the use of high-throughput sequencing to develop DNA markers is fast and effective. Comprehensive identification of DNA markers, including SVs and SSRs, would be of benefit to genetic diversity evaluation, genetic mapping, and molecular breeding of peach.

CHROMOSOME NUMBER, VOLUME AND NUCLEAR VOLUME RELATIONSHIPS IN A POLYPLOID SERIES (2X-20X) OF THE GENUS RUMEX

1971 ◽  
Vol 13 (4) ◽  
pp. 842-863 ◽  
Author(s):  
S. Ichikawa ◽  
A. H. Sparrow ◽  
C. Frankton ◽  
Anne F. Nauman ◽  
E. B. Smith ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Abrupt Change ◽  
Diploid Species ◽  
Nuclear Volume ◽  
Polyploid Series ◽  
Unidentified Species

Ninety-one acquisitions of the genus Rumex obtained from various sources were examined taxonomically and cytologically. These acquisitions included 36 species plus 2 unidentified species. The chromosome numbers counted were 2n = 14 (or 15), 16, 18, 20, 40, 42, 60, 80, 100, 120, 140, 160, ca. 170, 180 and ca. 200. The count of 2n = 180 made on one of the R. orbiculatus acquisitions is a new count for this genus, but other acquisitions had 160 and ca. 170. First counts were obtained for four species, R. frutescens (2n = 160), R. crystallinus (2n = 60), R. cristatus (2n = 80) and R. tenax (2n = 80). The count of 2n = 160 for R. frutescens is the highest chromosome number ever reported in the section Axillares. The chromosome numbers determined in R. palustris (2n = 60), R. confertus (2n = 100), R. arcticus (2n = 120) and R. aquaticus (2n = 140) differ from previously published counts. Our counts for eight other species support one of the previous counts where two or more counts are reported. It is shown that the species of the subgenus Acetosa sections Acetosa and Vesicarii and of the subgenus Platypodium have relatively large chromosomes, those of the subgenus Acetosa section Scutati and of the subgenus Acetosella have medium-sized chromosomes, and the members of the subgenus Rumex sections Axillares and Rumex have smaller chromosomes. The chromosomes of the diploid species of the section Rumex were larger than those of the polyploids (4x to 20x) of the same section. Within the section Rumex the log of nuclear volume increased with increasing ploidy, with an abrupt change (decrease) in slope between the 12x and 14x levels.

NULLISOMIC ANALYSIS OF NUCLEOLAR FORMATION IN ZEA MAYS

1978 ◽  
Vol 20 (1) ◽  
pp. 97-100 ◽  
Author(s):  
David F. Weber
Keyword(s):  
Zea Mays ◽  
Chromosome Number ◽  
Zea Mays L ◽  
Diploid Species ◽  
5S Rrna ◽  
Chromosome 6 ◽  
Chromosome 2 ◽  
Nucleolar Organizing Region

When a monosomic plant of a diploid species undergoes meiosis, two haploid and two nullisomic cells are produced. Zea mays L. microspore quartet cells nullisomic for chromosome number 1, 2, 4, 6, 7, 8, 9, or 10 produced by monosomics were analyzed. Cells nullisomic for chromosome 6, as expected, do not contain a nucleolus because chromosome 6 bears the nucleolar organizing region. Cells nullisomic for chromosome 2 contain nucleoli; therefore, the 5S rRNA template on chromosome 2 is not necessary for nucleolar formation. Cells nullisomic for chromosomes 1, 4, 7, 8, 9, or 10 also contain nucleoli; thus, no factors located on these chromosomes are necessary for nulceolar formation at the quartet stage.

Genetic relationship and polymorphism of selected medicinal plants of Asclepiadaceae using RAPD molecular analysis method

2021 ◽  
pp. 100101
Author(s):  
Boomibalagan Ponnerulan ◽  
Sivasangari Ramya Subramanian ◽  
Rajesekaran PE ◽  
Souravi Karpakal ◽  
Uthirapandi Veeranan ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Molecular Analysis ◽  
Genetic Relationship ◽  
Analysis Method

scholarly journals Use of Wild Arachis Species/Introgression of Genes into A. hypogaea L.

2001 ◽  
Vol 28 (2) ◽  
pp. 114-116 ◽  
Author(s):  
C. E. Simpson
Keyword(s):  
North Carolina ◽  
Chromosome Number ◽  
Wild Species ◽  
Diploid Species ◽  
Breeding Lines ◽  
B Genome ◽  
Improvement Programs ◽  
Selection For ◽  
Direct Dna Delivery ◽  
No Releases

Abstract The use of wild Arachis L. in cultivar improvement programs has been considered an option for more than 50 yr. Both A. Krapovickas and W.C. Gregory, independently, made interspecific hybridizations in the 1940s. However, only three cultivars have been released as a result of interspecific hybridizations, and only one of those has a clearly identifiable genetic component from the wild species. Several breeding lines have been reported and several germplasm releases are documented from Texas, North Carolina, and ICRISAT. At least four potential options exist for transferring genes from wild Arachis to the cultigen: a) The hexaploid pathway consists of crossing a diploid wild species directly with A. hypogaea, doubling the chromosome number to the hexaploid level, then backcrossing for several generations to restore the tetraploid condition. Several options are possible in this pathway involving various crossing schemes prior to crossing a diploid hybrid with A. hypogaea. North Carolina and ICRISAT have had success with this pathway. b) The diploid/tetraploid pathway has been the most successful in Texas to date. This pathway involves crossing diploid species (two to several), doubling the chromosome number of the hybrid, then crossing to A. hypogaea and backcrossing with selection for the desired character. This pathway is most successful when both A-and B-genome species are involved. Germplasm lines and a cultivar have been released in Texas using this pathway. c) Another diploid/tetraploid pathway could be to double chromosome numbers of diploid species and cross the amphiploids directly with A. hypogaea. Several attempts have been made with this technique, but no germplasm releases have been reported, in large part because sterility is too great when both A and B genomes are not included in the hybrid. Many of the sections/species of wild Arachis are so greatly isolated from A. hypogaea that plant transformation will be the likely method to introduce genes into the cultigen. d) Molecular methods of “inserting” genes into peanut that have been modestly successful and include use of Agrobacterium spp., electroporation, and direct DNA delivery techniques such as the gene gun, whiskers, and sonication. No releases have resulted.

scholarly journals Morphological, anatomical and karyological investigations of the Turkish endemic species Lathyrus woronowii Bornm. (Fabaceae)

2017 ◽  
Vol 76 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Fatma Güneş ◽  
Çiler Meriç
Keyword(s):  
Chromosome Number ◽  
Cross Sections ◽  
Endemic Species ◽  
Diploid Chromosome Number ◽  
Dam Construction ◽  
Annual Species ◽  
International Union ◽  
First Time ◽  
Iucn Criteria ◽  
General Appearance

AbstractLathyrus woronowiiBornm., an endemic species of Turkey, is threatened with extinction due to dam construction. It exists only in the Çoruh valley, Artvin. This annual species is in the critically endangered (CR) category according to the International Union of Conservation of Nature (IUCN) criteria. Its morphology, anatomy and karyology are studied here for the first time. A detailed description is given and the general appearance of the species has been drawn; cross sections from the stem and leaf have been taken and examined; and the diploid chromosome number (2n = 14) has been reported and illustrated for the first time.

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