Diversity of the Rysto gene conferring resistance to potato virus Y in wild relatives of potato.

BACKGROUND: Potato virus Y (PVY) is among the economically most damaging viral pathogen in production of potato (Solanum tuberosum) worldwide. The gene Rysto derived from the wild potato relative Solanum stoloniferum confers extreme resistance to PVY. RESULTS: The presence and diversity of Rysto were investigated in wild relatives of potato (298 genotypes representing 29 accessions of 26 tuber-bearing Solanum species) using PacBio amplicon sequencing. A total of 55 unique Rysto-like sequences were identified in 72 genotypes representing 12 accessions of 10 Solanum species and six resistant controls (potato cultivars Alicja, Bzura, Hinga, Nimfy, White Lady and breeding line PW363). The 55 Rysto-like sequences showed 89.87 to 99.98% nucleotide identity to the Rysto reference gene, and these encoded in total 45 unique protein sequences. While Rysto-like26 identified in Alicja, Bzura, White Lady and Rysto-like16 in PW363 encode a protein identical to the Rysto reference, the remaining 44 predicted Rysto-like proteins were 65.93 to 99.92% identical to the reference. Higher levels of diversity of the Rysto-like sequences were found in the wild relatives of potato than in the resistant control cultivars. The TIR and NB-ARC domains were the most conserved within the Rysto-like proteins, while the LRR and C-JID domains were more variable. Several Solanum species, including S. antipoviczii and S. hougasii, showed resistance to PVY. This study demonstrated Hyoscyamus niger, a Solanaceae species distantly related to Solanum, as a host of PVY. CONCLUSIONS: The new Rysto-like variants and the identified PVY resistant potato genotypes are potential resistance sources against PVY in potato breeding. Identification of H. niger as a host for PVY is important for cultivation of this plant, studies on the PVY management, its ecology, and migrations. The amplicon sequencing based on PacBio SMRT and the following data analysis pipeline described in our work may be applied to obtain the nucleotide sequences and analyze any full-length genes from any, even polyploid, organisms.

Comparing the toxicity of tungsten and vanadium oxide nanoparticles on Spirulina platensis.

The production and release of nanoparticles and their impacts on living organisms are among the most important concerns in the world. Spirulina platensis was chosen because of its ability to absorb more elements than other algae. Therefore, an experiment was conducted to improve the product quality of spirulina exposed to new type of nanoparticles. In this experiment, vanadium oxide nanoparticles (VNPs) and tungsten oxide nanoparticles (WNPs) were used at concentrations of 0, 0.001, 0.017, and 0.05 g/l. The measured indices such as protein percentage and concentrations of phycobiliproteins and carbohydrates were the most important parameters of spirulina. Results showed that the concentration of 0.001 g/l of VNPs significantly affected the amounts of protein and phycocyanin. It has also been observed that 0.001 g/l of WNPs significantly influenced the amounts of protein (5.3%) and phycocyanin (90%); however, WNPs at all concentrations increased the concentrations of protein and phycocyanin. A concentration of 0.05 g/l of WNPs increased phycocyanin content by 83% over the control. The examination of nanoparticles by spirulina showed that VNPs were more adsorbed by spirulina than WNPs. In general, VNPs were toxic to algae at concentrations of 0.017 and 0.05 g/l, but WNPs did not show any fatal toxicity.

QTLs position of some important ornamental traits in recently developed OO lily population.

Lilium L. is a perennial ornamental bulbous species, belonging to Liliaceae family, which consists of about 100 species. One of the most important hybrids in Lilium L. is the Oriental hybrid lily. Different cross combinations have been done in the lily family such as AA (Asiatic × Asiatic), AL (Asiatic × Longiflorum), and OT (Oriental × Trumpet). The OO (Oriental × Oriental) combination is a new one. SSR and AFLP markers were used to overlap each other and the genetic linkage groups were created according to the haploid number of lily chromosomes (12 linkage groups). In this experiment, the final F1 population, which creates a genetic linkage group, was 100 individuals. For map construction, JOINMAP 4.0 software by treating segregation data of markers as a CP (out breeder full-sib family) model was used. After evaluation of ornamental traits, MapQTL 4.0 software was also used to find possible QTLs on these linkage maps. A total of 940 primers were tested and the best ones, which were 172 primer pairs (96 AFLP and 76 SSR markers), were used for map construction and the total of 616 loci (465 loci for AFLP marker and 151 loci for SSR marker) were scored. The entire mapped length was 2144.2 cM. 8 QTLs were obtained for flower number which is an important trait in lily. Each QTL locus explained the phenotypic variation of 2.4-89.5%. The highest amount of LOD (35.21) was found in LG-F1P2 for FN4 QTL. For leaf number, one-QTL was mapped with LOD of 7.08 between 2 markers on the LG-M10 of maternal maps. The QTL for petal length was placed on the LG-F1P2 of the F1 hybrid maps on the E-CGC/M-CGC-4 primer combination. The petal width QTLs also were mapped on the E-CGC/M-CGC-4. Qualitative locus named LN was mapped on the LG-M10 of the maternal maps. PW2 QTL was also localized on the LG-F4 of the paternal maps. In this experiment, 5 QTLs also were mapped for spot number in all F1 hybrids and paternal and maternal maps, and spot size. Moreover, one QTL with the length of 51 cM was measured on the LG-M8 of the maternal maps. Plant height QTL with the LOD of 12.54 was mapped on the primer combination of E-CGC/M-CGC-4 on the LG-F1P2 of the F1 hybrid maps.

In vitro study on regeneration of Gladiolus grandiflorus corm calli as affected by plant growth regulators.

In this study, in vitro organogenesis of Gladiolus grandiflorus cultivar pink corm segments were evaluated by culturing corm calli in modified MS medium supplemented with 3% sucrose and 0.7% agar with different concentration of BAP (0, 1, 2 and 4 mg L(-1) medium) and NAA (0, 0.5, 1 and 2 mg L(-1) medium) in factorial experiment of Completely Randomized Design (CRD). In order to obtain Gladiolus calli, corm segments (Aprox. 5 x 5 x 1 mm in size) were kept in modified MS medium (Murashige and Skoog, 1962) that was supplemented with 1 mg L(-1) 2, 4-D, 3% sucrose and 0.7% agar. The results showed that increasing the concentration of BAP from 0 to 2 mg L(-1) medium simulated plantlet regeneration but no significantly effect was obtained on shoot and cormel organogenesis between 2 and 4 mg L(-1) BAP concentration in medium. Increasing of NAA content in media without BAP developed rootlet significantly. Interaction results showed that increasing BAP content against decreasing of NAA concentration stimulates the shoot and cormel proliferation.