Somaclones with typical and atypical shoots were regenerated from a callus culture in the same culture medium and in equal culture conditions. Since the genetic relationship among regenerated somaclones has not been investigated, current study employed heterologous microsatellite primers to examine the molecular diversity within and among somaclones, showing typical and atypical phenotypes with high morphological divergence. Nei identity value calculated between the somaclones was high (I = 0.929) and AMOVA showed higher genetic variation within (96%) than among (4%) the samples of somaclones. The polymorphism in the microsatellite loci indicated high levels of mean observed and expected heterozygosity in atypical somaclones, presumably with high adaptive potential and as source of genotypes for generation of new varieties of ornamental cacti. Low molecular divergence between typical and atypical morphologies of somaclones is a promising perspective for use of the atypical somaclones as source of chemical compounds of commercial and industrial interest. The somaclonal variations occurring in vitro callus culture has generated phenotypically differentiated subpopulations with low molecular divergence, however with high genetic variability, enough to be recommended as a source of genotypes to generate new varieties of ornamental cacti and of plants with new traits, necessary for breeding programs.

The ironstone outcrops in the rupestrian grasslands, known as cangas, are rich in species of endemic plants. This high endemism and the constant threat because of the area loss and fragmentation make the conservation of the rupestrian grasslands necessary. The rupestrian grasslands that host one of Brazil's largest iron-ore mining areas are Iron Quadrangle. About 89 rare and endangered species of the Iron Quadrangle are exclusive to cangas, including a threatened species Arthrocereus glaziovii. According to the International Union Conservation of Nature (IUCN), this species is considered micro-endemic and endangered and a priority for recovering the Iron Quadrangle's ferruginous rupestrian fields. This work aims to evaluate the potential distribution of A. glaziovii based on abiotic variables and soil elements and characterize the distribution of mining titles that may restrict the areas of occurrence of this species. We used five types of ecological niche model (ENM) algorithms (Bioclim, Domain, MaxEnt, GLM and RandomForest) in two sets of environmental variables for the modeling: 20 climatic variables and 18 edaphic variables. Our results showed that the area of the potential occurrence of A. glaziovii is more extensive and covers areas outside the Iron Quadrangle. However, mining titles currently licensed and in exploration correspond the entire identified area, threatening the species' survival.

Lack of water and salinity are common problems in many parts of the world. Therefore, some types of cacti can represent as promising crops. Therefore, the ability of cactus species to survive and adapt under natural stress conditions should be evaluated. In this study, it was aimed to evaluate the effect of salt stress on germination and emergence of pitaya seeds obtained from different fruit flesh colors, priming with plant growth regulators, namely salicylic acid (SA), oxalic acid (OA) and mepiquat chloride (MC). The experiment had a completely randomized design with a 2×4×3 factorial scheme corresponding to two pitaya cultivars (white and red fleshed), four NaCl concentrations (0, 2500, 5000 and 10000 ppm), and three PGRs (150 ppm/MC, SA, OC). The following variables were analyzed; germination percentage, mean germination time (MGT), germination stress tolerance ındex (GSTI), shoot length, seedling fresh weight and seedling dry weight ratio. According to the results, it was determined that the growing environment of the seed was important in salt stress resistance, while seeds matured in the environment with red fruit flesh were more tolerant to salt stress than white. Although Pitaya species are relatively salt tolerant, growth (about 30%) was significantly reduced above 2500 ppm and germination (about 45%) above 5000 ppm. MC was found promising as a priming agent in seeds obtained from fruits with white fruit flesh, and OA was found promising as a priming agent in seeds obtained from fruits with red fruit flesh in reducing NaCl-induced stress. Germination percentage stood out as the most important trait determining seed quality and was found to have positive effects on germination stress tolerance index (r: 0.63), seedling length (r: 0.74) and fresh seedling weight (r: 0.56). It is thought that the results obtained may contribute to pitaya cultivation and breeding.