Molecular sexual determinants in Pistacia genus by KASP assay.

BACKGROUND: Pistacia is a genus of dioecious plant species whose trees can take 4-5 years to reach the economically valuable fruit-bearing stage. The fruits have great importance as raw material in the food, healthcare, and baking industries. For that reason, the identification of individual plants in the early juvenile period for the pollination and positioning of trees is crucial for growers. The objective of this study is to develop markers for each Pistacia species that can help in screening the sex of plant seedlings before they reach the reproductive stage, without waiting for morphological characteristics to appear. METHODS AND RESULTS: Within this context, by using the power of the kompetitive allele-specific PCR (KASP) assay technology as a marker screening system, we successfully discriminated seven out of eight Pistacia species: P. atlantica, P. integerrima, P. khinjuk, P. mutica, P. terebinthus, P. vera, and P. lentiscus. We used a high-throughput DNA sequence read archive (SRA) to assemble a reference genome that was employed in our studies as a de novo bioinformatics method. Four genomic regions from SRA and three single-nucleotide polymorphism (SNP) positions from Kafkas et al. BMC Genomics 16:98, 2015) were selected and sequenced with collected plant material from predominantly the Antepfistigi Research Institute Collection Garden, and eight species were aligned intraspecifically for SNP mining. In total, 12 SNP markers were converted to KASP markers, and 5 of them (SNP-PIS-133396, SNP-PIS-167992, P-ATL-91951-565, P-INT-91951-256, P-KHI-91951-115) showed clear allelic discrimination between male and female plants. SNP-PIS-167992 and P-ATL-91951-565 were identified as the best marker assays because they showed allelic frequency differences for all individuals and for both homozygous and heterozygous characters. These markers could be the most comprehensive ones for the whole genus because they showed discriminative power for several species. CONCLUSIONS: This study is the first one to use the KASP assay for sex discrimination in Pistacia species, and it can be regarded as a precursor study for sex discrimination by KASP for plants in general.

SSR Markers Suitable for Marker Assisted Selection in Sunflower for Downy Mildew Resistance.

The effectiveness of Pl genes is known to be resistant to downy mildew (DM) disease affected by fungus Plasmopara halstedii in sunflower. In this study phenotypic analysis was performed using inoculation tests and genotypic analysis were carried out with three DM resistance genes Plarg, Pl13 and Pl8. A total of 69 simple sequence repeat markers and 241 F2 individuals derived from a cross of RHA-419 (R) x P6LC (S), RHA-419 (R) x CL (S), RHA-419 (R) x OL (S), RHA419 (R) x 9758R (S), HA-R5 (R) x P6LC (S) and HA89 (R) x P6LC (S) parental lines were used to identify resistant hybrids in sunflower. Results of SSR analysis using markers linked with downy mildew resistance genes (Plarg, Pl8 and Pl13) and downy mildew inoculation tests were evaluated together and ORS716 (for Plarg and Pl13), HA4011 (for Pl8) markers showed positive correlation with their phenotypic results. These results suggest that these markers are associated with DM resistance and they can be used successfully in marker-assisted selection for sunflower breeding programs specific for downy mildew resistance.