Parental UV-B Environment Affects The Strategies Of Clonal Plants For Light Selection

In nature,plants are usually in heterogeneous habitats,the habitat selection behavior of clonal plants contributes to obtaining the pathy distributed resources effectively,which help them adapt to the heterogeneous environment.It has been proved that the growth of the offspring ramets are affected by their parental environment,therefore,the habitat selection behavior of clonal plants is likely to be regulated by parental environment.Furthermore,as an inherent component of solar spectrum,UV-B radiation plays an important role in the growth and development process of plants,thus,UV-B radiation experience of the parental ramets must also affect the habitat selection behavior of clonal plants,but there are no reported about it.In this study,the parental ramets of clonal Duchesnea indica were treated with different intensity of UV-B(0,5 and 10?w·cm^-2),while the offspring grow in heterogeneous light environment(light versus shade),the effects of parental UV-B radiation on the habitat selection behavior of the offspring ramets in heterogeneous light habitats were investigated by analyzing parental total DNA methylation variation and growth traits of parental and offspring ramets.The main research results are as follows:(1)The habitat selection behavior of offspring ramets was modified by parental UV-B experience.For instance,more biomass of offspring ramets allocated in shade habitat,the stolon of genet with high-radiated-parent bent to the shade habitat earlier.(2)Offspring ramets with high-radiated-parent the shade avoidance syndrome in shade was inhibited by the denser growth pattern.While,the genet with low-radiated-parent displayed more extended pattern in light environment.(3)In addition,parental direct UV-B not only increased their total DNA methylation level,depressed their growth,but also inhibited the growth of clonal genets.Moreover,the changes of parental DNA methylation level were significantly correlated with some growth traits of parental(leaf area,petiole length and specific petiole length)and offspring ramets(biomass,branching intensity and leaf/stolon biomass allocation).Consequently,these results suggested that offspring could perceive the parental UV-B environment and regulate their behavior under heterogenous light condition,which was most likely due to the maternal effect induced by epigenetic variation of parent.In conclusion,UV-B radiation is an important factor in regulating the selection behavior of D.indica,some performance of offspring ramets induced by parental UV-B experience could help them pre-regulating their growth to copy with future UV-B environment.These results will help us to understand the effects of UV-B radiation on plants and the environmental adaptation strategies of clonal plants comprehensively.