S05 - Session P6 - Tarenaya Cultivars: Genome Size and Genetic Diversity

Authors: Sylvia Plaschil *, Simone Abel, Beate Kollatz, Holger Budahn

The spider flower, Tarenaya hassleriana (syn. Cleome spinosa ), belongs to the family Cleomaceae, that originates in South America and is used as ornamental plant. Cultivar series were bred on a small scale, and showed low morphological diversity. The used gene pool is mostly unknown. Therefore, genome size and genetic diversity of six generatively and ten vegetatively propagated cultivars were determined. Different companies provided these cultivars for a field trail at the Saxon State Office for Environment, Agriculture and Geology in Dresden, Germany, in 2021. 168 individual bands from RAPD/dpRAPD analysis were recorded as 1/0 matrix and used for estimation of the genetic distance by the program TREECON in UPGMA mode. The tree was inferred by bootstrap analysis (1000 iterations). The molecular analysis showed a clear discrimination between T. boliviensis and the cultivars as well as between the generatively and vegetatively propagated cultivars. Within the cultivar groups, the genetic variation was found to be highly reduced. For flow cytometry, leaf and petal samples of the cultivars in three biological replicates were prepared using the CyStain ® PI Absolute P Kit (Sysmex, Germany) consisting of nuclei extraction and staining buffer, propidium iodide and ribonuclease A. Measurements were performed using the flow cytometer CytoFLEX (Beckman Coulter). For 2C DNA content the mean peak positions of the internal standard tomato 'Stupicke' (2C = 1.96 pg) and sample were analyzed supported by the software CytExpert 2.3. The 2C values discriminated into two groups. Group 1 varied from 0.64 pg to 0.67 pg and included all generatively and three vegetatively propagated cultivars. Group 2 varied from 0.92 pg to 1.01 pg and consisted of seven cultivars and the species T. boliviensis . These results could support further breeding and enhancement of variability of ornamental Tarenaya .