RESUMO
Rye (Secale cereale) is an important diploid (2n = 14, RR) crop species of the Triticeae and a better understanding of its organellar genome variation can aid in its improvement. Previous genetic analyses of rye focused on the nuclear genome. In the present study, the objective was to investigate the organellar genome diversity and relationships of 96 accessions representing diverse geographic regions using chloroplast (cp) and mitochondrial (mt) DNA PCR-RFLPs. Seven cpDNA and 4 mtDNA coding and noncoding regions were amplified using universal cpDNA and mtDNA primer pairs. Each amplified fragment was digested with 13 different restriction enzymes. mtDNA analysis indicated that the number of polymorphic loci (20) was low and genetic differentiation (GST) was 0.60, excluding the outgroups (hexaploid wheat, Triticum aestivum, 2n = 6x = 42, AABBDD; triticale, xTriticosecale Wittmack, 2n = 6x = 42, AABBRR). cpDNA analysis revealed a low level of polymorphism (40%) among the accessions, and GST was 0.39. Of the 96 genotypes studied, 70 could not be differentiated using cpDNA PCR-RFLPs even though they are from different geographic regions. This is most likely due to germplasm exchange, indicating that genotypes might have a common genetic background. Two cpDNA and 3 mtDNA fragments were significantly correlated to the site of germplasm collection. However, there was no clear trend. These results indicate that the level of organellar polymorphism is low among the cultivated rye genotypes. The cpDNA and mtDNA PCR-RFLP markers used in the present study could be used as molecular markers in rye genetics and breeding programs.
Assuntos
Genoma de Planta , Geografia , Organelas/genética , Secale/genética , Enzimas de Restrição do DNA/metabolismo , DNA de Cloroplastos/genética , DNA Mitocondrial/genética , DNA de Plantas , Genótipo , Técnicas de Amplificação de Ácido Nucleico , Filogenia , Folhas de Planta/química , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Componente PrincipalRESUMO
OBJECTIVE: To report the pregnancy outcome after transabdominal multifetal pregnancy reduction in multiple pregnancies achieved by intracytoplasmic sperm injection. METHODS: One twin and 13 triplet pregnancies obtained by intracytoplasmic sperm injection underwent pregnancy reduction. Pregnancies were achieved with ejaculated sperm in 8, testicular sperm in 3, and epididymal sperm in 2 of these cases. All triplet pregnancies were reduced to twins at 10-12 weeks' gestation by transabdominal potassium chloride injection. A twin pregnancy with spina bifida affecting 1 fetus was reduced to singleton at 18 weeks of pregnancy. RESULTS: There was no failed procedure and no pregnancy loss within the first 4 weeks after the procedure. A complete miscarriage (7.1%) developed in 1 case at 17 weeks' gestation which was due most probably to the incompetent cervix. In utero fetal death occurred in 1 fetus of another reduced pregnancy. Three of the reduced pregnancies delivered at term, after 37 completed weeks, four premature deliveries occurred between 31 and 35 gestational weeks, and four pregnancies were ongoing beyond 25 weeks' gestation. A total of 16 fetuses, from seven twin and two singleton pregnancies, were delivered without perinatal mortality. CONCLUSIONS: Although the sample size was small, our experience indicates that the reduction of triplets obtained by sophisticated infertility treatments such as intracytoplasmic sperm injection using testicular or epididymal sperm seems to be a safe method and can be effectively used.