Using the collection of wild species in sunflower breeding

Abstract

We started to collect wild sunflower (Helianthus L) species in 1998. The main task of this collection is to promote the development of new breeding material. In particular, it was planned to use the wild species as resistance sources to the major diseases of sunflower and as Rf genes sources to the new CMS types. The collection consists presently of 140 accessions of annual wild species and 110 samples of 27 perennial ones. The assessment of the wild sunflowers collection for resistance to Sclerotinia (Sclerotinia sclerotiorum) Phomopsis {Phomopsis helianthi) and broomrape (Orobanche cumana) was carried out on artificial infectious backgrounds. Resistance to other diseases was estimated simultaneously under natural infection. The immunologic potential of the collection was assessed three times during the vegetative period: at early stages of ontogeny (first week of June), at full flowering (second week of August) and at the end of the vegetation period (fourth week of September). A group of 101 samples showed various types of resistance to a complex of diseases. F1 and F2 generations were produced from more than 100 cross combinations of sunflower inbred lines and wild annual species. The tolerance to Phomopsis in field conditions was recorded in the F1 and F2 interspecific hybrids. Also, several sources of fertility restoration for new CMS types (ANN1, ARG1, PEF1, GIG1 and RIG1) have been found among the accessions of wild annual sunflower species. Thus, certain samples from the collection may be useful for breeding to disease resistance. The development of new initial material for sunflower breeding has already started.