Variation in germination rates of moss spores using a cryopreservation technique: A case study of spores from six moss species

doi:10.3969/j.issn.1000-5641.2019.03.015

Abstract

Abstract: To evaluate the applicability of cryopreservation for bryophyte spores, this study explored the effect of dehydration time and low temperature pretreatment; the study was used to identify the optimal conditions for six moss spores collected from different habitats. In addition, varying time periods (1 d, 15 d, 30 d, 90 d, 180 d) of spore cryopreservation were studied under the optimal pretreatment conditions identified. The results showed that:①After dehydration and low temperature pretreatment, the highest germination rates of spores from the six moss species were maintained (87.25%~96.21%). ②Compared to low temperature pretreatment, dehydration seems to be the key point of success for spore cryopreservation. The average spore germination rates ranged from 74.97% to 96.21% when treated with dehydration alone; in comparison, germination rates ranged from 21.73% to 90.94% when pretreated with low temperature alone. ③The average germination rates of spores from five moss species maintained their respective highest level (87.25%~96.21%) after cryopreservation for 1 d and then decreased with the prolongation of storage time; nevertheless, the germination rates still remained at relatively high levels (73.69%~86.60%).④ The average germination rates of spores from Funaria hygrometrica, Pohlia elongate, and Trematodon longicollis after storage for 30 d were 86.49%, 86.60%, and 84.98%, respectively. The germination rates of spores from Bryum blindii and B. caespiticium reached 73.69% and 84.17%, respectively, after storage for 180 d. The study indicates that the procedure for spore cryopreservation could be a simple, stable, and efficient method for storage of bryophyte species in conservation programs.

Key words: bryophyte, moss, habitats, spores, cryopreservation

CLC Number:

Q94.331

SUN Li-wei, GAO Xue-di, XU Dan-er, Wang Shu-qin, YANG Zhuo-jun, WANG Jian. Variation in germination rates of moss spores using a cryopreservation technique: A case study of spores from six moss species[J]. Journal of East China Normal University(Natural Sc, 2019, 2019(3): 138-143,154.

References

[1] VANDERPOORTEN A, GOFFINET B. Introduction to Bryophyte[M]. Cambridge:Cambridge University Press, 2010:1-2.
[2] HYLANDER K, JONSSON B G. The conservation ecology of cryptogams[J]. Biological Conservation, 2007, 135(3):311-314.
[3] PATIÑO J, MATEO R G, ZANATTA F, et al. Climate threat on the Macaronesian endemic bryophyte flora[J/OL]. Scientific Reports, 2016. Doi:10.1038/srep29156. https://www.nature.com/articles/srep29156.pdf
[4] PENCE V C. Cryopreservation of bryophytes:The effects of abscisic acid and encapsulation dehydration[J]. Bryologist, 1998, 101(2):278-281.
[5] BURCH J, WILKINSON T. Cryopreservation of protonemata of Ditrichum cornubicum (Paton) comparing the effectiveness of four cryoprotectant pretreatments[J]. CryoLetters, 2002, 23(3):197-208.
[6] BURCH J. Some mosses survive cryopreservation without prior treatment[J]. Bryologist, 2003, 106(2):270-277.
[7] ROWNTREE J K, RAMSAY M M. How bryophytes came out of the cold:Successful cryopreservation of threatened species[J]. Biodiversity and Conservation, 2009, 18:1413-1420.
[8] PANGUA E, GARCIA-ALVAREZ L, PAJARÓN S. Studies on Cryptogamma crispa spore germination[J]. American Fern Journal, 1999, 89(2):159-170.
[9] ROGGE G D, VIANA A M, RANDI A M. Cryopreservation of spores of Dicksonia sellowiana:An endangered tree fern indigenous to south and central America[J]. CryoLetters, 2000, 21:223-230.
[10] SEGRETO R, HASSEL K, BARDAL R, et al. Desiccation tolerance and natural cold acclimation allow cryopreservation of bryophytes without pretreatment or use of cryoprotectants[J]. Bryologist, 2010, 113(4):760-769.
[11] VAN ZANTEN B O, GRADSTEIN S R. Experimental dispersal geography of neotropical liverworts[J]. Beiheft zur Nova Hedwigia, 1988, 90:41-94.
[12] 李秋萍, 姜丽佳, 鲁蓓蓓, 等. 细叶小羽藓孢子的超低温保存[J]. 华东师范大学学报(自然科学版), 2014(6):121-125.
[13] 杜荣骞. 生物统计学[M]. 北京:高等教育出版社, 2003.
[14] WIKLUND K, RYDIN H. Ecophysiological constraints on spore establishment in bryophytes[J]. Functional Ecology, 2004, 18(6):907-913.
[15] FULLER B J. Cryoprotectants:the essential antifreezes to protect life in the frozen state[J]. CryoLetters, 2004, 25(6):375-388.
[16] 简令成. 低温生物学与植物种质的长期保存[J]. 植物学通报, 1998, 5(2):65-68.
[17] 徐艳, 刘燕, 石雷. 大叶黑桫椤孢子超低温保存[J]. 植物生理学通讯, 2006, 42(1):55-57.
[18] WU S P, QIN Z Z, XIAO T Z, et al. Cryopreservation of gemmae of Marchantia polymorpha L. (Marchantiophyta, Marchantiaceae) without prior pretreatment[J]. CryoLetters, 2015, 36(2):91-96.