Li Junmin, Qi Caihong, Gu Jingjing, Jin Zexin
Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation Taizhou University Taizhou China.
Traffic Patrol Headquarters of Public Security Bureau of Chongqing City Vehicle Management Institute Chongqin China.
Ecol Evol. 2020 Apr 3;10(9):4091-4103. doi: 10.1002/ece3.6179. eCollection 2020 May.
Cheng et S. Y. Chang (Calycanthaceae), which has a unique systematic status, is listed as a national second-class protected plant of China. In this study, the genetic diversity, performance, and fitness of F1 progeny from crosses between the Damingshan (DMS) population of and pollen parents from the Daleishan (DLS) and Longxushan (LXS) populations were examined. The DLS population has a relatively small population size, low genetic diversity, and considerable geographical and genetic distances from the DMS population relative to the LXS population. Compared with naturally occurring seeds, DLS-sired seeds had the highest thousand-seed weight, starch content, fat content, germination rate, germination index, and emergence rate, but the lowest protein content. Naturally occurring, open-pollinated seeds had the lowest thousand-seed weight, starch content, and fat content, but the highest protein content. Compared with natural F1 progeny, DMS × DLS seedlings had the highest genetic diversity, photosynthetic parameters, and growth characteristics, except for leaf mass ratio and stem mass ratio. Under strong light, DMS × DLS seedlings exhibited a / value of 0.75, while the other two seedling types exhibited / values of 0.65. DLS-sired seeds had the most vigorous growth characteristics except for leaf mass ratio and stem mass ratio. These results suggest that genetic rescue by transplanting seedlings from the DLS population or hand pollination with pollen from the DLS population would be effective methods to reduce inbreeding depression and obtain strong offspring with high genetic diversity and fitness in the DMS population.
沉水樟（樟科）具有独特的系统地位，被列为中国国家二级保护植物。在本研究中，对大明山（DMS）种群与大瑶山（DLS）和龙秀山（LXS）种群的花粉亲本杂交产生的F1代子代的遗传多样性、表现和适合度进行了研究。DLS种群的种群规模相对较小，遗传多样性较低，与DMS种群相比，在地理和遗传距离上相对于LXS种群更远。与自然产生的种子相比，DLS授粉的种子千粒重、淀粉含量、脂肪含量、发芽率、发芽指数和出苗率最高，但蛋白质含量最低。自然产生的、开放授粉的种子千粒重、淀粉含量和脂肪含量最低，但蛋白质含量最高。与自然F1代子代相比，DMS×DLS幼苗除叶质量比和茎质量比外，具有最高的遗传多样性、光合参数和生长特性。在强光下，DMS×DLS幼苗的光化学猝灭系数（qP）/非光化学猝灭系数（NPQ）值为0.75，而其他两种幼苗类型的qP/NPQ值为0.65。除叶质量比和茎质量比外，DLS授粉的种子生长特性最为旺盛。这些结果表明，通过移植DLS种群的幼苗或用DLS种群的花粉进行人工授粉进行遗传拯救，将是减少近亲繁殖衰退并在DMS种群中获得具有高遗传多样性和适合度的强壮后代的有效方法。
