Broomrape is a very serious problem for sunflower
One of the most dangerous threats to the cultivation of sunflower is the parasite broomrape (Orobanche cumana Walls.). It can suck in yields of 20, 50, and even 100%, depending on the conditions of cultivation and resistance of varieties and hybrids to this parasite. Until recently, the main area of its distribution was the areas where sunflower is widely grown, particularly, the south and east of Ukraine. Changing climatic conditions towards aridity in the forest-Steppe zone and even Polissia area caused an increase in acreage under oilseed crop, and its high profitability of production helped to reduce the time of sunflower return to the previous place and failure to crop rotation, which led to deterioration of phytosanitary status.
Thus, the top is already spreading to the north of Ukraine. This is facilitated by the lightness of the parasite seeds, which is capable of transporting air for tens of kilometers. Contamination of new areas is also due to a technique where, for example, rented harvesters, after harvesting sunflower in areas infected with broomrape, drive hundreds of kilometers into fields where broomrape problems have never occurred. Therefore, now, except for the southeastern regions of Ukraine, the Poltava, Kiev, Cherkasy, Vinnytsia regions are already affected by a broomrape. The spread of broomrape in these areas is also explained by the neglect of rotation.
Breeding remains a modern method of increasing yields also due to resistance to biotic and abiotic factors, and the genetic tolerance of hybrids to broomrape is a key method of combating it.
Recognizing the importance of this problem, the specialists of LIST LLC since 2010 have started to actively carry out breeding work to identify resistant to new growth genotypes. The beginning of this work is the discovery of a phytotron using the express method of evaluation of selection samples of sunflower. To infect the soil of the phytotron with a broomrape of sunflowers, breeders of LLC “LIST” regularly collect broomrape seeds in different regions of Ukraine and CIS. Seeds of sunflower lines and hybrids are sown in the contaminated soil. This creates an artificial, very aggressive backdrop in the phytotron. It provides an opportunity for a short period of 35-40 days, to evaluate the breeding material, to select unstable genotypes to the top and to introduce further crossbreeding lines combining resistance to the top and a complex of other economic and valuable features.
The result of long-term resultful work is creation of two hybrids Liman OR and Commandor 777, resistant to the seventh race G. These hybrids combine the above resistance to sunflower seeds with high drought tolerance and environmental durability, ie, the ability to withstand unsustainable level of tolerance Steppe, and with high productivity potential when growing under favorable conditions of the Forest Steppe.
Breeding at LIST LLC continues in different directions and among new developments – the creation of modern genotypes that are more resistant to the broomrape of the latest races and mutations, which in some regions are beginning to affect the hybrids of many breeding companies resistant to the seventh race. The new sunflower lines demonstrate resistance to the most aggressive sunflower seed plants, and hybrids with the participation of such lines are being tested and will soon be included in the Register of Plant Varieties of Ukraine to provide domestic farmers with so much needed innovation.