Adaptive specifics of broomrape’s (Orobanche cumana Wallr.) ontogenesis on sunflower

There were observed the changes in the tubercle of O.cumana from high-virulent populations of Rostov region of RF, which favour the increase of seed productivity and the reduction of terms of fruiting shoots’ development. These changes are: the formation of multiple meristematic zones in tubercle and the simultaneous development of several adventive shoots from them, and also the development of apexes of tubercle rudimentary roots into secondary shoots. There were found out the longevity of tubercle and the formation of new shoot apexes in it after seeds’ filling of the main shoot. The polymorphism of inflorescence is observed by number of setting flowers and their distribution all over the stem, even below the soil level. The flowering ability was revealed in flower buds hidden in soil and the formation of seed-bearing fruits from them.