Facultatea de Biologie și Geoştiinţe / Faculty of Biology and Geosciences
Permanent URI for this communityhttps://msuir.usm.md/handle/123456789/4
Browse
3 results
Search Results
Item EFFICIENCY OF MICROSATELLITE MARKERS IN GENOTYPING OF OROBANCHE CUMANA POPULATIONS(Iasi University of Life Sciences, 2021-10-21) Mutu, Ana; Clapco, Steliana; Duca, MariaMicrosatellites or simple sequence repeats (SSRs) markers are widely dispersed across the genome, have a codominant and multiallelic nature, high variability and informativeness, and a specific chromosomal location. For this reason, they are playing a significant role in different fundamental and applicable fields, including genetic studies at the individual, population, species levels, and molecular breeding programs. In this study, the utility of 15 microsatellite markers in discrimination of 33 Orobanche cumana (broomrape) populations from different geographical locations was assessed: Republic of Moldova (11 populations), Romania (1), Bulgaria (4), Serbia (7), Turkey (7) and China (3). The PCR amplification products obtained showed differences by number and size depending on the markers used (3 and 16 alleles). A total of 110 alleles with fragment sizes ranged from 76-343 bp were determined. The evaluation of the genetic polymorphism of SSR markers was performed by the effective number of alleles per locus (Ne) with an average of 5.31, Polymorphic Information Content index (PIC) – 0.75, Nei's genetic diversity index (H) – 0.78 and, Resolving Power index (Rp) – 5.79. High values of all indices revealed the significant informative capacity and effectiveness of markers studied. At the same time, most markers showed PIC values higher than 0.5, indicating a high polymorphism in O. cumana populations. Seven microsatellite markers (Ocum-052, Ocum-059, Ocum-074, Ocum-081, Ocum-087, Ocum-196, Ocum-197) were selected based on the analyzed statistical parameters, suggesting that these markers can efficiently measure genetic diversity in broomrape. Based on the Rp index and PIC values of these 15 SSR markers, genetic diversity of Turkish (Rp: 4.774; PIC: 0,722) and Moldavian (Rp: 4.394; PIC: 0,716) Orobanche cumana populations was higher than in other populations. However, the studied microsatellite (SSR) markers system characterized very well the genetic structure of all O. cumana populations included in this study. Selected markers could eventually be useful for breeders and sunflower seed producers to improve their control strategies for this parasitic plant.Item DISCRIMINATING ABILITY OF ISSR MARKERS IN THE REVEALING OF THE GENETIC POLYMORPHISM IN TURKISH BROOMRAPE POPULATIONS(Trakya University Publisher, 2021-08-29) Duca, Maria; Bivol, InaIn the present study, the analysis of the informativity level and discriminatory capacity for 14 ISSR-markers to identify polymorphism of seven Orobanche cumana populations from different geographical regions of Turkey was performed. ISSR markers utility was assessed by calculating of different parameters such as the polymorphism information content (PIC), observed and effective number of alleles (Na and Ne), Nei's and Shannon diversity indexes (H and I), number and percentage of polymorphic loci, resolving power (Rp), Simpson's coefficient (Hj). Out of 207 amplicons generated by microsatellites primers, 195 were found polymorphic (94.29%) and 12 were monomorphic with size range from 341 to 5353 bp. The average number of amplified bands was 14.79 fragments per primer. The PIC values for 14 primers ranged from 0.18 ((GATA)4) to 0.41 ((AG)8YA) with the mean value 0.34 Eight primers ((AG)8YA, (CT)8TC, BC807, BC841, (CA)6AC, (CTC)4RC, (CAG)5, BC835) were considered the most effective. The mean I value was 0.52 and ranged from 0.32 ((GATA)4) to 0.6 ((AG)8YA). The (AG)8YA, (CT)8TC, BC807, BC841, (CTC)4RC, (CA)6AC and (CAG)5 primers had the highest I values. The Rp ranged from 5.9 for primer (CA)6RG to 22.59 for primer (AG)8YA. Nine of the ISSR primers ((AG)8YA, (CTC)4RC, BC810, BC807, BC841, BC835, (CAG)5, BC857 and (CT)8TC) possessed high Rp values (22.59, 19.12, 16.83, 16.54, 16.49, 14.59, 13.32, 12.88 and 11.37, respectively) and were able to distinguish all 41genotypes. The higher discrimination potential calculating by the Simpson’s coefficient had primer BC810 (0.33) and the lower (CA)6RG (0.01), the mean value for all primers was 0.18. According to ISSR data analysis, the high proportion of the genetic variability (94.29%) was due to interpopulation variation and 45.82% of the diversity by cause of intrapopulation variations. In conclusion, in this comparative study of the discrimination capacity of 14 ISSR markers using to broomrape population genetic analysis, the tri- ((CTC)4RC, (CAG)5) and dinucleotide ((AG)8YA, BC807, BC841, (CT)8TC) primers proved more informative than tetranucleotide repeats. Moreover, these primers revealed the highest values for all analyzed polymorphism information indexes of genetic diversity (number of amplicons per primer from 15 to 28, level of polymorphism more than 88.89%, PIC≥0.36, I≥0.53, Hj≥0.11 and Rp≥11.37) for Turkish broomrape populations. The analysis of ISSR-markers showed that this type of marker is applicable for the assessment of intra- and interpopulation genetic polymorphism for species O. cumana.Item THE EVOLUTION OF OROBANCHE CUMANA RACES IN SUNFLOWER CROP IN THE REPUBLIC OF MOLDOVA(Trakya University Publisher, 2021-09-01) Duca, Maria; Clapco, StelianaOne of the most critical constraints for sunflower production in the majority of European countries, as well as in the Middle East and Asia is broomrape (Orobanche cumana Wallr.) – non-photosynthetic, obligatory, root parasitic plant. The continuous introduction of new resistant sunflower hybrids exerts a selection pressure on broomrape populations evolution and contribute to the development of new more virulent races that overcome sunflower genetic resistance. Thus, until now, eight races of O. cumana, A through H, have been identified. In this study, the chronology of broomrape races occurrence in sunflower crop in the Republic of Moldova was analysed. In Moldova sunflower broomrape was firstly attested at the end of the 19th century. In 1937 a more virulent race B was identified especially in the regions situated along the border with Romania. Later, at the beginning of 1970s, a new biotype that infested sunflower genotypes carrying genes of resistance to races A and B occurred. This new race was called the Moldovan race or race C and was found preferentially in the central part of the country. In early 2000s the presence of races D, E and F in Moldovan sunflower fields was reported. The most spread were the less virulent races A, B and D, which were found in all part of the country, followed by race E detected in the South and Centre and more virulent race F, which was identified only in the Central part. In few years, the study of racial status demonstrated the presence in the south of the country of a new highly virulent race G, which overcame all known genes of resistance. It has been established that the populations from the northern part of the Republic of Moldova belonged predominantly to race E, those from the central part of the republic – to race F and southern populations were attributed to the race G. Our greenhouse test carried out in 2014 revealed, for the first time, the presence in sunflower fields of the most aggressive race H. This pathotype was found especially in the south and centre and sporadically in the north. A research performed recently (2019-2020) showed the occurrence of new highly aggressive biotypes able to infest even the genotypes considered resistant to the most virulent race H. According to the results, in a short period of time new aggressive races of O. cumana occurred and spread rapidly over all Moldovan sunflower growing regions, the most virulent races G and H becoming dominant.