**5. Conclusions**

The ratio of 6:3:1 distribution patterns of *P. limprichtii* within the population in Huanglong District seems to reveal that pollinators, herbivores, and survival adaptability could promote the development of such a reproductive strategy in the population to maintain the maximum population density. Function and expression patterns indicated that *PlFLS* probably is a crucial gene in the formation of white and pigmented flowers. *PlANS* and *PlUFGT* were found to determine the color intensity in pigmented flowers. In addition, a putative MBW complex, *PlMYB10*/*PlbHLH2*0/*PlWD40-1* or *PlMYB10*/*PlbHLH26*/*PlWD40-1* may serve as a repressor of regulated *PlFLS* expression that is responsible for variation in the color intensity of *P. limprichtii*. Our results provide valuable molecular information on floral color variations in *Pleione*, and also provide inspiration to further explore the relationship between color polymorphism and species evolution and to study its contribution to color evolution.

#### **Supplementary Materials:** Supplementary materials can be found at http://www.mdpi.com/1422-0067/21/1/247/s1.

**Author Contributions:** This study was conceived by S.W. and Z.L. Y.Z. performed the transcriptome and gene expression analysis and wrote the manuscript. T.Z. and Z.D. helped with the sampling and field work. X.D., W.L., and M.C. helped to perform the experiment. C.L. and X.W. revised the manuscript. W.-C.T. and J.Z. provided writing guidance. All authors contributed to revising the manuscript. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was supported by the Fujian Natural Science Foundation Project (grant no. 2019J01410), the Fujian Agriculture and Forestry University 2015 Outstanding Youth Fund Project (grant no. xjq201620), and the Fujian Agriculture and Forestry University Science and Technology Innovation Special Fund Project (grant no. KFA17331A).

**Acknowledgments:** The authors thank Bai-Jun Li, Jie-Yu Wang, Yan-Qiong Chen, Guo-Qiang Zhang, Si-jin Zeng, Zhi-yao Ren, and Xueyan Yuan who helped with this research. We also thank Qi-Xuan Peng and other staff of Huanglong National Scenic Reserve for assisting sampling.

**Conflicts of Interest:** The authors declare no conflict of interest. Huanglong National Scenic Reserve help to sample, and OmicShare company help to analysis raw data.
