Origanum L. is one of the high-value medicinal and aromatic plants generally used for various purposes in the field of food and health. This study evaluated the effect of aqueous extract, hydrosol and essential oil forms of seven Origanum taxa including three endemic species in fresh-cut mushroom samples in order to prevent polyphenol oxidase (PPO) activity. Food samples were treated with these natural preservatives (aqueous extract, hydrosol, and essantial oil) and stored at 4°C temperature for a maximum of 5 days. It was found that the extract form of Origanum vulgare L. subsp. hirtum (Link) Ietsw. provided maximum PPO inhibition with 64.50% of reduction on 3rd day. Similarly, 3-fold reduction in hydrosol application was observed with Origanum bilgeri P. H. Davis which is the endemic plant. These results were conducted with the extract forms containing water are more effective than essential oil form to inhibit PPO activity. Practical applications In this study, we have investigated alternative usage of some Origanum plants as natural anti-browning food additives in mushroom samples. The samples separately treated with aqueous extract, hydrosol, and essential oil forms of different Origanum plants were stored until 5 days. PPO activities of samples on 1st, 3rd, and 5th days were used to determinate the shelf life of mushrooms associating with their browness. How to cite this article: Tanhaş E, Martin E, Korucu EN, Dirmenci T. Effect of aqueous extract, hydrosol, and essential oil forms of some endemic Origanum L. (Lamiaceae) taxa on polyphenol oxidase activity in fresh-cut mushroom samples. J

In section Leiopetali, the diploid chromosome numbers were reported from only six of total 25 taxa. There is no karyological data relating to other 19 taxa. In this study, it is intended to determine the diploid chromosome numbers of taxa of section Leiopetali. The diploid number of 13 species were detected, four of which were recorded for the first time and nine numbers compatible with the previous reports. Twelve species were diploid with 2n = 2x =30. D. leptopetalus was diploid and polyploid, which reveals only one polyploidy level of tetraploidy (2n = 4x = 60). Polyploidy might have played a role in the karyotype evolution of the genus. One of the most important reasons for this situation is that although polyploidy is observed in the genus Dianthus, the dysploidy mechanism that causes a change in the basic chromosome number has not been found until now. The basic number is x = 15 according to the all chromosomal reports. In conclusion, this study reports new data into the karyological characteristics of section Leiopetali (genus Dianthus) that can be useful for interpreting or understanding relationships among sections.

In section Dentati, the chromosome numbers were reported from only eight of 30 taxa. There is no chromosomal record relating to the other 22 taxa. In the present study, it is intended to detect the chromosome numbers of section Dentati taxa. Chromosome numbers of 15 taxa were obtained, 13 of which were reported for the first time and two numbers agreed with the previous reports. 14 taxa were diploid with 2x = 30 and only one taxon was polyploid with 4x = 60. Polyploidy might have played a role in the karyotype evolution of the genus. Although polyploidy was seen, there was no dysploidy causing to change in the basic chromosome number. According to all chromosomal data on Dianthus, the basic chromosome number was only one (x = 15). In conclusion, this study presents new data into the karyological characteristics of section Dentati (genus Dianthus) that may be useful for understanding or interpreting relationships among the sections.