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Karyotype and standard ideograms of Striped flying barb (Esomus metallicus) which were collected from Huai Seng Reservoir, Surin Province were studied. 10 males and 10 females were selected for investigation. Chromosomes were prepared from kidney by squash technique and were stained by conventional staining and Ag-NOR banding techniques. The results showed that the diploid number of Striped flying barb was 2n= 50 and the fundamental number (NF) was 78 in both male and female. The karyotype consisted of 2 large submetacentric, 4 large acrocentric, 12 medium submetacentric, 10 medium acrocentric and 22 medium telocentric chromosomes. The NORs bearing chromosomes were detected on the short arm of the large acrocentric chromosome pairs 8th. In addition, there was no difference in the sex chromosomes between male and female. The karyotype formula of Striped flying barb is as follows: 2n (50) = Lm 2 + La 4 + Msm 12 + Ma 10 + Mt 22 [ABSTRACT FROM AUTHOR]

A traditional karyomorphological approach was carried out in order to investigate the cytotaxonomic relationships among the species of the Santolina chamaecyparissus complex. All the 14 species included in this species complex were analysed for a total of 39 populations. Metaphase plates were obtained by squashing root tips stained with Feulgen technique. Measurable metaphase plates available in literature were also re-analysed. Chromosome number (2n), total haploid (monoploid) length (THL), and karyotype asymmetry indices (CVCL and MCA) were calculated for each of the 14 species. Chromosome data are provided for the first time for S. benthamiana and S. vedranensis, while a new hexaploid cytotype is reported for S. villosa. Five different ploidy levels are detected: diploid, triploid (a single individual of the otherwise diploid S. virens), tetraploid, pentaploid, and hexaploid. Our analyses reveal that polyploids are characterized by a more asymmetric karyotype with respect to diploids. The possible origin of polyploids, and in particular of the cultivated pentaploid S. chamaecyparissus, is briefly discussed. [ABSTRACT FROM AUTHOR]

Meiotic behavior is of great importance for the development of genetic improvement programs, especially in species such as vanilla (Vanilla planifolia Jacks.), which are severely affected by various biotic and abiotic factors derived from their narrow genetic base. Therefore, the present work was proposed with the objective of evaluating the meiotic behavior of the commercial morphotype "Mansa" from the municipality of "Papantla de Olarte" in Veracruz, Mexico. For this purpose, flower buds of different sizes were collected and fixed in Carnoy using the squash technique, followed by staining with 2% (w/v) acetocarmine to clearly observe all the stages of the meiotic process. Normal meiotic behavior and a haploid chromosome number (n = 8) were observed. These results may be useful for the development of breeding programs for this crop. [ABSTRACT FROM AUTHOR]