Thladiantha dubia (Cucurbitaceae) in the Republic of Bashkortostan as a Dangerous Weed with High Invasive Potential

Abstract

Thladiantha dubia Bunge is a perennial herbaceous climbing liana from Cucurbitaceae family, which is found naturally in the Russian Far East (mainly in the south of Primorsky krai) and beyond in Northeastern China and on the Korean Peninsula. T. dubia is cultivated for decorative purposes, but owing to the ability to rapidly reproduce by underground tubers, it often turns into a dangerous weed. T. dubia is common in Russia, as well as in Japan, Europe, the United States, and Canada. We have found and studied large invasive populations of T. dubia in several villages of the Republic of Bashkortostan, in an area of 60 km north of the city of Ufa. In this area, it is known exclusively as a dangerous and hard-to-eradicate weed; it appeared here in the 1970s and continues to propagate rapidly by pieces of tubers during mechanical soil treatment. By artificial reproduction of T. dubia plants by small pieces of tubers in laboratory conditions, a very high capability of vegetative reproduction of this plant was revealed. Comparative RAPD and ISSR analyses of samples from the natural population of T. dubia from Primorsky krai of the Russian Federation and its invasive population from the Republic of Bashkortostan showed genetic differences between the analyzed populations, which can be a reflection of the formation of an aggressive form of this plant in the secondary range. From the data we have received and from the literature, it follows that T. dubia species needs to be classified as a weed with a high invasive potential, and therefore, during its cultivation, all necessary measures should be taken to exclude its distribution in natural biocoenoses and agroecosystems.