Fitness of sexual reproduction of Toona ciliata var. pubescens natural populations and their sexual reproduction and regeneration

doi:10.13287/j.1001-9332.201804.001

Abstract

Abstract: To examine the reproduction fitness coefficients and individual-level fitness of Toona ciliata var. pubescens, their sexual reproduction and natural regeneration were investigated during 2006-2016, with four natural populations in Jiulianshan National Reserve as test objects. The results showed that there were only 2-10 trees for the natural populations of T. ciliata var. pubescens with a small initial number of fruiting plants (3-9 trees), which were from the initial fruiting plants or their first/second generation. The sexual reproduction of these isolated populations were significantly different, and their seed production capacities tended to decline over time. With the maturing of communities, soil seed banks and seed germinations were extremely poor, and the number of trees that could be growing to mature stage was nearly zero. The optimum maturity age of T. ciliata var. pubescens was about 40 a, and the fitness coefficients (2.0-2.8) rapidly increased in early development stage, but then was sharply reduced (0.3-0.5), and then gradually dropped to almost 0. There were significant differences in the fitness at individual level (0-14 tree·cm^-2) among different populations, but their values were low (close to zero). Based on the existing reproduction rate, the actual values of sexual reproduction and regeneration fitness were much lower than the predicted ones. Due to the low level of genetic fitness, the sexual reproductive ability of different populations all showed decreasing trends. The natural sexual regeneration ability tended to decline, while the fitness of T. ciliata var. pubescens further decreased. All those factors suggested higher investment risks. Therefore, the systems of sexual reproduction became unbalanced and deteriorating. We proposed that more studies, including breeding mating, pollination, seed setting, and genetic diversity evaluation, are needed. Moreover, we should provide suitable forest environment through cleaning up litter in the fruiting stage and applying appropriate thinning during the transition period from seedling to young tree growth.

HUANG Hong-lan, ZHANG Lu, JIA Li-ming, LIANG Yue-long, CAI Jun-huo. Fitness of sexual reproduction of Toona ciliata var. pubescens natural populations and their sexual reproduction and regeneration[J]. Chinese Journal of Applied Ecology, 2018, 29(4): 1098-1106.

References

[1] Chen Y-C (陈毓川), Pei R-F (裴荣富), Zhang H-L (张宏良), et al. The geology of nonferrous and rare metal deposits related to Mesozoic granitoids in the Nanling region, China. Acta Geoscientica Sinica (地球学报), 1990, 11(1): 79-85 (in Chinese)
[2] Liu X-Z (刘信中), Xiao Z-Y (肖忠优), Ma J-H (马建华). Scientific Survey and Study on the Forest Ecosystem in Jiulianshan Natural Reserve. Beijing: China Forestry Press, 2002 (in Chinese)
[3] Jian M-F (简敏菲). Research on Distribution Pattern and Vegetation Dynamics of the Evergreen Broad-leaved Forest in Mount Jiulianshan of Jiangxi Province. PhD Thesis. Nanchang: Nanchang University, 2008 (in Chinese)
[4] Liu J (刘军). Study on Genetic Structure of Natural Populations of Toona ciliata var. pubescens. PhD Thesis. Beijing: Chinese Academy of Forestry, 2007 (in Chinese)
[5] Huang H-L (黄红兰). The Population Ecological Characteristics of Toona ciliata var. pubescens in Jiulianshan National Reserve. PhD Thesis. Nanchang: Jiangxi Agricultural University, 2012 (in Chinese)
[6] Xiao Y-F (萧运峰). Investigation on Toona ciliata var. pubescens from Anhui Province. Acta Phytoecologica Sinica (植物生态学报), 1983, 7(2): 152-157 (in Chinese)
[7] Liu J (刘军), Chen Y-T (陈益泰), Luo Y-F (罗阳富), et al. Study on community characters of Toona ciliata var. pubescens natural forest. Forest Research (林业科学研究), 2010, 23(1): 93-97 (in Chinese)
[8] Wen Q (温强), Ye J-S (叶金山), Zhou C (周城). Analysis of genetic diversity of natural populations of Toona ciliata var. pubescens in Jiangxi Province. South China Forestry Science (南方林业科技), 2016, 44(3): 1-6 (in Chinese)
[9] Liu J (刘军), Jiang J-M (姜景民), Zou J (邹军), et al. Genetic diversity of central and peripheral populations of Toona ciliata var. pubescens, an endangered tree species endemic to China. Chinese Journal of Plant Ecology (植物生态学报), 2013, 37(1): 52-60 (in Chinese)
[10] Guo X-H (郭新弧), Zhou S-D (周树德), Chen R-J (陈仁钧), et al. Survey of Toona ciliata var. pubescens community at Ting County in Anhui Province. Journal of Anhui Normal University (Natural Science) (安徽师范大学学报: 自然科学版),1983(2): 63-71 (in Chinese)
[11] Wang R-W (王瑞文), Li L (李玲), Guo Y (郭赟), et al. Effect of illumination time on the seedling activity of Toona ciliata var. pubescens. Seed (种子), 2017, 36(5): 40-43 (in Chinese)
[12] Guo X-Y (郭晓燕), Zhang L (张露), Liang Y-L (梁跃龙), et al. Simulation study on the effects of litter layer thickness on seedling emergence of Toona ciliata var. pubescens. Acta Agriculturae Universitatis Jiangxiensis (江西农业大学学报), 2014, 36(2): 332-337 (in Chinese)
[13] Yang Q-P (杨清培), Fu F-L (付方林), Zhang L (张露), et al. A study on the neighborhood interrerence index in Toona ciliates var. pubescens community. Acta Agriculturae Universitatis Jiangxiensis (江西农业大学学报), 2013, 35(4): 748-754 (in Chinese)
[14] Harper JL. The Population Biology of Plants. New York: Academic Press, 1977
[15] Venable DL, Brown JS. The ecology of seed heteromorphism in Heterosperma pinnatum in Central Mexico. Ecology, 1988, 68: 65-76
[16] Institute of Genetics of Fudan University (上海复旦大学). Genetics Dictionary. Beijing: Science Press, 1979 (in Chinese)
[17] Laudan L, Fang Z-Q (方在庆). Progress and Its Problems. Shanghai: Shanghai Translation Press, 1991 (in Chinese)
[18] Dong G-A (董国安). The propensity interpretation of fitness its cognitive meanings, Ziran bianzhengfa Yanjiu. Studies in Dialectics of Nature (自然辩证法研究), 2005, 21(3): 28-31 (in Chinese)
[19] Zhong Z-C (钟章成). Reproductive strategies of plant populations. Acta Ecologica Sinica (生态学报), 1995, 14(1): 37-42 (in Chinese)
[20] Chen S (陈尚), Ma Y (马艳), Li Z-Z (李自珍), et al. Analysis and measurement of the fitness of seed reproduction and vegetative reproduction of clonal plant. Acta Ecologica Sinica (生态学报), 1999, 19(2): 287-290 (in Chinese)
[21] Chen Q (陈奇), Li D-L (李大林), Huang X-Y (黄雪燕). Laws of the change in genotype entropy of the general population by means of fitness. Journal of Guangxi Agricultural and Biological Science (广西农业生物科学), 2014, 33(1): 174-178 (in Chinese)
[22] Li D-L (李大林), Chen Q (陈奇). Influence of law of segregation on population genetic polymorphism and causes of heterosis speculated based on fitness. Molecular Plant Breeding (分子植物育种), 2016, 14(8): 2155-2160 (in Chinese)
[23] Booy G, Hendricks RJ, Smulders MJ. Genetic diversity and the survival of populations. Plant Biology, 2000, 2: 379-395
[24] Kozlowski J. Measuring fitness in life history studies. Trends in Ecology & Evolution, 1993, 8: 84-85
[25] Moles AT, Falster DS, Leishman MR, et al. Small seeded species produce more seeds per square meter of canopy per year, but of not per individual per lifetime. Journal of Ecology, 2004, 92: 384-396
[26] Wu G-L (武高林), Du G-Z (杜国祯), Shang Z-H (尚占环). Contribution of seed size and its fate to vegetation renewal: A review. Chinese Journal of Applied Ecology (应用生态学报), 2006, 17(10): 1969-1972 (in Chinese)
[27] Stearns SC. The Evolution of Life Histories. Oxford: Oxford University Press, 1992
[28] Barot S, Heino M, Brien L, et al. Estimating reaction norms for age and size at maturation when age at first reproduction is unknown. Evolutionary Ecology Research, 2004, 6: 659-678
[29] Van TR, Bijlsma R, Ouborg NJ, et al. Relationships between plant density, out crossing rates and seed set in natural and experimental populations of Scabiosa columbaria. Journal of Evolutionary Biology, 1994, 7: 287-302
[30] Hogbin PM, Ayre DJ, Whelan RJ. Genetic variation and reproductive success of road verge populations of the rare shrub Grevillea barklyana (Proteaceae). Heredity, 1998, 80: 180-186
[31] Kato E. Fruit set in Styrax obassia (Styracaceae): The effect of light availability, display size, and local floral density. American Journal of Botany, 1999, 86: 495-501
[32] Zhang J-M (张纪卯), Chen W-R (陈文荣), Bao X-H (鲍晓红), et al. The standard of selecting superior trees from Toona ciliata var. pubescens plantation. Subtropical Agriculture Research (亚热带农业研究), 2016, 12(4): 224-230 (in Chinese)
[33] Huang H-L (黄红兰), Zhang L (张露), Liao C-K (廖承开). Seed rain, soil seed bank, and natural regeneration of natural Toona ciliata var. pubescens forest. Chinese Journal of Applied Ecology (应用生态学报), 2012, 23(4): 972-978 (in Chinese)
[34] Gadgil M, Bossert W. Life history consequences of natural selection. American Naturalist, 1970, 104: 124
[35] Chen Y (陈艳), Su Z-X (苏智先). Research on the protection of Davidia involucrata populations, a rare and endangered plant endemic to China. Acta Ecologica Sinica (生态学报), 2011, 31(19): 5466-5474 (in Chinese)
[36] Zhi Y-B (智颖飙), Yang C (杨持), Wang Z-S (王中生), et al. The endangered characteristics and mechanism of the endemic relict shrub Tetraena mongolica Maxim. Acta Ecologica Sinica (生态学报), 2008, 28(2): 767-776 (in Chinese)
[37] Zhang L (张莉), Zhang X-P (张小平). Population characteristics of Coptis chinensis var. brevisepala in Anhui Province and its endangering mechanism. Chinese Journal of Applied Ecology (应用生态学报), 2005, 16(8): 1394-1398 (in Chinese)
[38] Gao R-M (高润梅), Shi X-D (石晓东), Fan L-Y (樊兰英), et al. Natural distribution and community ecological characteristics of Taxus chinensis var. mairei in Shanxi Province,China. Chinese Journal of Applied Ecology (应用生态学报), 2016, 27(6): 1820-1828 (in Chinese)
[39] He W-M (何维明), Zhong Z-C (钟章成). The concept and research contents of plant reproductive stra-tegy. Journal of Biology (生物学杂志), 1997, 14(6): 1-3 (in Chinese)
[40] Zhang Y-F (张玉芬), Zhang D-Y (张大勇). Asexual and sexual reproductive strategies in clonal plants. Chinese Journal of Plant Ecology (植物生态学报), 2006, 30(1): 174-183 (in Chinese)