Resumen
- In 2017, ProvisiaTM quizalofop-p-ethyl (QFE) resistant rice became a new alternative for the chemical control of in-season red rice (Oryza sativa L. sp. spontaneum) infestations in Louisiana rice farms. Until then, Clearfield® imidazolinone resistant rice was the only alternative that US farmers had for the efficient in-season chemical control of red rice. ProvisiaTM rice is a BASF Corporation patented technology that can serve as an alternative for rotation with Clearfield® rice. This strategy seeks to prevent outcrosses between red rice and herbicide resistant varieties, and consequently extend the life span of both technologies. This research aimed to dissect the inheritance of the resistance to QFE in ProvisiaTM rice as a first step for incorporation into the LSU AgCenter hybrid rice germplasm. This inheritance study demonstrated that the trait is governed by a single dominant gene that segregates following a Mendelian fashion with no maternal cytoplasmic effects. Additionally, SNP-based markers which properly tagged the QFE resistance were developed. QFE resistance was transferred to Environmental Genic Male Sterile (EGMS) lines using different crossing strategies. The objective was to develop QFE resistant EGMS lines adapted to local growing conditions and the cereal chemistry profile of US long grain varieties. During the 2016 growing season, a total 211 QFE resistant EGMS were selected for future evaluation. These were in the F3:4, F4:5 and F5:6 generations representing different crosses with different cereal chemistry profiles inherited from the parents utilized. A subset of these lines were used to develop and evaluate 42 new QFE-resistant hybrids during the 2016 summer season and 143 QFE resistant hybrids during 2017. Experimental hybrids were identified that combined QFE herbicide resistance with levels of heterosis comparable to commercial hybrid varieties.