No abstract

distributed from West Europe and Northwest Africa to West China, with the center of species diversity in the Balkan Peninsula and Turkey. Turkey is the richest country with 137 Crocus taxa (Harpke et al., 2012; Ruksans, 2017). Different conventional morphological features used in Crocus taxonomy with regards to possibly distinguishing monophyletic groups within the genus have been reported in the literature (Harpke et al., 2012, 2014; Carta et al., 2015), in which it was found that none of the traditional morphological features were suitable for discriminating Crocus sections or series. This status has caused some problems in their classification; therefore, additional characteristics that can assist the existing diagnostics are needed for the classification of Crocus taxa. Crocus seed color, structure, and surface sculpture are of much importance in terms of taxonomical applications (Maw, 1886). However, with the exception of a few studies (Kujat and Rafiński, 1978; Grilli Caiola et al., 2010; Carta et al., 2015), Crocus seed has not been a popular research subject. Mathew (1982) attributed this situation to the fact that the capsules and seeds of crocuses flowering in either autumn or spring reach maturity during April and May. According to our experiences from field observations, it is hard to find and collect capsules on the ground when vegetation is dense and tall. Therefore, Crocus seed studies require the cultivation of related taxa and capsule and seed harvesting should be done carefully. Seeds and fruits may possess various macro-and micromorphological structures that can provide valuable information for plant taxonomy. The shape, color, size, and especially microstructure (including anatomical features) of the seeds and fruits are valuable information for plant systematics (Kerndorff et al., 2015). There have been many plant epidermal surface analyses using scanning electron microscopes (SEMs). According to Barthlott (1981), surface characteristics can basically be divided into 4 main groups: 1) cellular arrangement, 2) shape of the cells, 3) relief of the outer cell walls, and 4) epicuticular secretions. These characteristics vary widely among species and at the family level, and are not easily affected by environmental conditions. Moreover, Kerndorff et al. (2015) stated that the microstructures of Crocus seed testae are very taxonomically valuable, and just this character alone can be adequate for a systematic grouping of the genus. In addition, the seed anatomical characters are generally as useful as the morphological characters for plant identification and are frequently used in the discrimination of closely related taxa (Karamian et al., 2012; Karaismailoğlu, 2015).

&"Crocus sativus is the source of saffron, which is made from dried stigmas of the plant. $'"It is a male-sterile triploid that ever since its origin has been propagated vegetatively. $("The mode of evolution and area of origin of saffron are matters of long-lasting $)" debates. Here we analyzed chloroplast genomes, genotyping-by-sequencing (GBS) $*" data, nuclear single-copy genes, and genome sizes to solve these controversial %+"issues. We could place 99.3% of saffron GBS alleles in Crocus cartwrightianus, a %!" species occurring in southern mainland Greece and on Aegean islands, identifying it %#" as the sole progenitor of saffron. Phylogenetic and population assignment analyses %$" together with chloroplast polymorphisms indicated the wild C. cartwrightianus %%" population south of Athens as most similar to C. sativus. We conclude that the crop is %&" an autotriploid that evolved in Attica by combining two different genotypes of C. %'" cartwrightianus. Vegetative propagation prevented afterwards segregation of the %(" favorable traits of saffron. %)" %*"