Interactions between genetics and environment shape Camelina seed oil composition

Abstract

Background Camelina sativa (gold-of-pleasure) is a traditional European oilseed crop and emerging biofuel source with high levels of desirable fatty acids. A twentieth century germplasm bottleneck depleted genetic diversity in the crop, leading to recent interest in using wild relatives for crop improvement. However, little is known about seed oil content and genetic diversity in wild Camelina species. Results We used gas chromatography, environmental niche assessment, and genotyping-by-sequencing to assess seed fatty acid composition, environmental distributions, and population structure in C. sativa and four congeners, with a primary focus on the crop’s wild progenitor, C. microcarpa. Fatty acid composition differed significantly between Camelina species, which occur in largely non-overlapping environments. The crop progenitor comprises three genetic subpopulations with discrete fatty acid compositions. Environment, subpopulation, and population-by-environment interactions were all important predictors for seed oil in these wild populations. A complementary growth chamber experiment using C. sativa confirmed that growing conditions can dramatically affect both oil quantity and fatty acid composition in Camelina. Conclusions Genetics, environmental conditions, and genotype-by-environment interactions all contribute to fatty acid variation in Camelina species. These insights suggest careful breeding may overcome the unfavorable FA compositions in oilseed crops that are predicted with warming climates.

Winter camelina seed quality in different growing environments across Northern America and Europe

“…Camelina is no exception. Recently, Brock et al (2020) demonstrated that seed oil content and FA composition significantly differ among Camelina species and can substantially differ within the species due to growth conditions, especially temperature. Temperature greatly affects FA synthesis (Singer et al, 2016), and it is common for seed storage lipids to increase in unsaturation under low temperatures and display greater saturation under high temperatures (Linder, 2000).…”

On the proper type designation for Camelina microcarpa, a wild relative and possible progenitor of the crop species C. sativa (Brassicaceae)

“…Thus, we conclude that Andrzejowski originally collected specimens of C. microcarpa somewhere in the eastern part of the presentday Moldova or adjacent parts of Ukraine (probably Odessa Region), along the left (eastern) bank of the Dnister [Nistru in Moldovan/Romanian, also Dniester] River between Camenca town and the confluence of the Dnister and Yagorlyk [Iagorlîc] rivers, most probably on limestone outcrops because plants typical for the whole "limestone area" in Andrzejowski's lists in that chapter were marked by asterisks. This suggests that the type of C. microcarpa probably belongs to the southern Ukrainian populations, which are genetically different from northern and central Ukrainian ones (Brock et al, 2020).…”

“…A traditional European oilseed crop Camelina sativa (L.) Crantz (Brassicaceae) is becoming increasingly popular as an emerging biofuel source (Vollmann & Eynck, 2015;Blume & Rakhmetov, 2017;Brock et al, 2018Brock et al, , 2020Guittet et al, 2018;etc.). Taxa of the genus Camelina Crantz also served as classical models for important early studies of microevolution, crop origins, and co-evolution of crops and their specialized weeds.…”

“…All those factors stimulated recent integral research of C. sativa and its wild relatives and possible progenitors, including aspects of their taxonomy, phylogeny, biogeography, genetics, biochemistry, biotechnology, etc. (see Martin et al, 2017;Brock et al, 2018Brock et al, , 2019Brock et al, , 2020Čalasan et al, 2019;Luo et al, 2019;Mandáková et al, 2019;Chaudhary et al, 2020).…”

“…Considerable differences between western and eastern groups of populations of plants currently classified as C. microcarpa were revealed in the Eurasian steppe zone by Čalasan et al (2019). Also, two genetically distinct groups of populations can be distinguished in Ukraine, the southern and northern-central ones (Brock et al, 2020). Thus, for achieving a reliable infraspecific classification of the species and the actual limits of species in the group (which is also important for crop improvement), the proper typification of the name C. microcarpa is crucial.…”