Haematococcus pluvialis, as the most potential natural source of astaxanthin, which is a powerful antioxidant with high economic value, has attracted more and more scientific attention in recent years. An in-depth understanding of the mechanism for how H. pluvialis produces astaxanthin requires the intensive investigations on its genetic information. In particular, many reported studies were based on a variety of RNA analyses. However, it is difficult to extract RNA with high quality and quantity from H. pluvialis, because of the blockage from its thick cell wall and contamination by a large quantity of pigments, polysaccharides, and lipids. Therefore, we proposed an optimized Trizol-based RNA extraction method for H. pluvialis by investigating the effect of cell wall broken ways, algal strains, and cell growth status on total RNA isolation. Using this rapid, convenient, and cost-saving method, isolated H. pluvialis RNA had high quantity and quality (with an RNA integrity number of 7.0 and a concentration of 1604.1 ng/μL) equivalent to that isolated by commercial kit, enabling its applications into downstream RNA analyses.
Sugarcane (Saccharum sp, Poaceae) is native to Southeast Asia, and due to growing demand as raw material, its cultivation recently expanded to new frontiers. The genetic diversity analysis is essential for targeting strategies in the formation and maintenance of a germplasm. This study aimed to assess the genetic diversity of 26 accessions of sugarcane from the Active Germplasm Bank of Embrapa Coastal Tablelands, using inter-simple sequence repeat (ISSR) molecular markers. Sixteen primers were used, resulting in 87 fragments with 91.13% of polymorphism. The similarity of the individuals ranged between 0.22 and 0.87. Individuals RB867515 and RB92579 were closer genetically, and the most distant ones were PI240785 and NSL 291970. Four distinct clusters were formed, using UPGMA. This information can be used to prioritize the selection of accessions for the conduction of hybridization in breeding and germplasm exchange actions.
The Alcantarea patriae is a Bromeliaceae endemic to the inselbergs of the Atlantic Forest. This taxon, described in the year of 2007 by Versieux & Wanderley, presents restricted and fragmented distribution outside conservation units. Studies to evaluate the genetic structure of its populations can contribute to the conservation and management strategies for the species. In this study, 31 microsatellite markers, descriptive to six different Bromeliaceae species, were evaluated by cross-amplification tests in 20 individuals of A. patriae. The individuals were collected in the district of Vila Cruzeiro, in the municipality of Jerônimo Monteiro. Twelve markers were polymorphic and 10 monomorphic, with an amplification success rate of 71%. The displayed polymorphism information content was considered high, indicating that the selected markers are informative. The values found for the fixation index were positive and indicated the occurrence of inbreeding. The mean number of alleles was 4.66 (3-6), the mean expected and observed heterozygosities were 0.6605 and 0.4618, respectively. The detection of polymorphic markers was important for future studies of diversity and genetic structuring of natural populations and for germplasm bank creation aiming to contribute to in situ and ex situ conservations of A. patriae.
Pak choi is a highly nutritious vegetable that is widely grown in China, Southeast Asia, and other parts of the world. Because it reproduces by seed, it is very important to understand the mechanism of floral organ development. Therefore, using the Chinese cabbage genome as a reference, this study analyzed the expression profiles of shoot apex genes at flower bud differentiation stages 1 and 5, in order to identify genes related to floral organ development. The results showed that the proportion of mapped genes was high, with 84.25 and 83.80% of clean reads from the two sample saligned to the reference genome, respectively. A total of 525 differentially expressed genes (DEGs) were identified, 224 of which were upregulated and 301 were downregulated. The expression levels of genes homologous to Chinese cabbage flowering genes were also analyzed at stages 1 and 5; the expression levels of Bra012997 (ap1), Bra000393 (SOC1), and Bra004928 (SOC1) were significantly upregulated at stage 5, suggesting that these three genes positively regulate floral development in pak choi. DEGs involved in floral organ development were analyzed with homologous genes from Arabidopsis thaliana; the homologous genes Bra029281 (AGL42), Bra026577 (ARPN), Bra022954 (SPL3), Bra029293 (ARF2), Bra007978 (AtRLP12), Bra033221 (SPL8), Bra008037 (LOX4), Bra001598 (IAA19), Bra003892 (PATL1), Bra038778 (AT4G21323), Bra025315 (KLCR2), and Bra013906 (DTX35) are directly related to floral organ development in Arabidopsis, suggesting that these genes have corresponding functions during flower organ development in pak choi, and could be candidates for further genetic research. These results provide a foundation for research on the molecular mechanism of flower organ development in pak choi and other Brassica rapa vegetables.
This study aimed to evaluate the genetic variability of the teak germplasm bank, using morphological traits and inter-simple sequence repeat molecular markers. Thirty clones were evaluated in a randomized complete block design with three replicates, and each plot was composed of three plants. A joint analysis of quantitative and qualitative variables was performed using the Gower algorithm. Quantitative, qualitative, and molecular variables were analyzed simultaneously using the Ward-MLM procedure. There is genetic variability among the 30 teak genotypes studied, considering the quantitative, qualitative, and molecular variables by the Ward-MLM statistical procedure. Morphological traits used proved to be efficient for the study of genetic variability; however, it was not possible to compose a descriptor table for clonal teak genotypes based on the traits evaluated. The Gower method was efficient in discriminating the groups, demonstrating that the simultaneous analysis of qualitative and quantitative data is feasible and can allow greater efficiency in the knowledge of the variability among teak genotypes. The genotype 22 showed to be the most divergent compared to the other genotypes, except for the cluster of genotypes by the UPGMA method based on the Gower distance obtained by the Ward-MLM procedure, which formed a group with genotypes 9 and 30, in the morphological and molecular analyses and was grouped alone.
