The possibility of using wild sunflower’s resistance to imidazolinones

Abstract

The objective of this investigation was to determine the reaction of wild sunflower to a number of acetolactate synthase (ALS) inhibitors. We used a wild sunflower (Helianthus annuus L) population from Kansas known to be resistant to imazethapyr and tested it with other herbicides from the group of imidazolinones (imazamox, imazapyr) and sulfonylurea herbicides (primisulfuron - methyl, rimsulfuron, thifensulfuron - methyl, prosulfuron oxasulfuron, iodosulfuron-methyl-Na, chlorsulfuron and triflusulfuron-methyl). Another aim of this piece of research was to determine the genes responsible for this resistance as well as the mode of inheritance. In order to achieve this aim, we crossed wild sunflower resistant to imazethapyr with susceptible inbred line Ha-26. In the greenhouse, we made the F2 generation of this interspecific cross as well as the BC1 and BC2. The obtained results showed that the previously detected resistance includes not only imazethapyr but also imazamox and imazapyr Imidazolinone-resistant wild sunflower is susceptible to the normal use rates of chlorsulfuron, iodosulfuron, oxasulfuron, prosulfuron and rimsulfuron. This means that it will be possible to use these herbicides in the future to control imazethapyr-resistant sunflowers in areas where no resistance to sulfonylurea herbicides has been registered. F1 progeny of wild sunflower crossed to the cultivated sunflower exhibited partial resistance to imazethapyr, imazamox and imazapyr in field conditions. The results showed that the resistance is semi-dominant in F1 generation. The segregation ratio in the F2 generation is 1:2:1 for semi-dominance. The incorporation of this trait into the cultivated sunflower would significantly improve the control of weeds in sunflower, since the currently used methods do not provide an efficient weed control in this crop species.

Cilj rada bio je da se ispita reakcija divljeg suncokreta poreklom iz Kanzasa prema prema herbicidima iz grupa imidazolinona i sulfonilurea, kao i da se utvrdi način nasleđivanja rezistentnosti prema imazetapiru, da bi se ovo svojstvo sa većom verovatnoćom prenelo u komercijalne inbred linije suncokreta. Pored ranije registrovane otpornosti divljeg suncokreta iz Kanzasa prema imazetapiru i imazamoksu, dokazana je i rezistentnost ovog suncokreta prema imazapiru. Ovo svojstvo moguće je iskoristiti za stvaranje rezistentnog kulturnog suncokreta i samim tim omogućiti primenu ovih herbicida u suzbijanju korova. Rezistentan suncokret prema imidazolinonima osetljiv je prema većem broju sulfonilurea herbicida, a naročito prema hlorsulfuronu, prosulfuronu, rimsulfuronu i oksasulfuronu. Način nasleđivanja rezistentnosti prema imidazolinonima je parcijalna dominacija i za nju je odgovoran jedan gen.