蒙古扁桃(Amygdalus mongolica)种子萌发及幼苗生长对胁迫的响应

doi:10.7522/j.issn.1000-694X.2016.00135

摘要/Abstract

摘要： 为了探讨蒙古扁桃（Amygdalus mongolica）种群退化原因和实生苗繁育的疑难问题，以祁连山中部蒙古扁桃种子为材料，采用室内控制干旱胁迫、混合盐胁迫、变温与种子剥壳相结合的处理方法，研究了种子萌发及幼苗生长对逆境生态因子的响应。结果表明：采用清水对照、-0.15 MPa PEG溶液处理，种子萌发率差异不显著（P>0.05）；不同PEG溶液处理（-0.32、-0.54、-0.81 MPa）条件下，种子萌发率依次极显著降低（P<0.01）；-1.15 MPa处理条件下，种子不萌发；蒙古扁桃的种子萌发时间随着干旱加剧推迟，种子萌发指数、活力指数、初生芽、根长、次生根个数和幼苗鲜重随水势极显著降低（P<0.01），但在-0.32 MPa处理下壮苗指数极显著增高，-0.15 MPa处理次之；种子萌发的最低渗透势阈值为-0.81 MPa。种子萌发的最低混合盐胁迫阈值为1.6%，在轻度混合盐（0.2%~0.4%）胁迫下，初生根长度和次生根数量增加，随混合盐胁迫加剧，初生芽长度、幼苗鲜重降低，表明幼苗对轻度混合盐胁迫首先采取降低生长量，促进根生长来进行适应。经低渗透势或高浓度混合盐胁迫后，部分种子休眠而保持生活力，未能萌发的种子复水后萌发率高达62%~96%，一次萌发率与恢复萌发率累计之和与对照萌发率无差异（P>0.05）。种皮障碍是制约蒙古扁桃种子萌发的主要原因，机械破除果皮可打破种子休眠，低温层积（2~5℃）能极显著提高蒙古扁桃种子活力，变温层积（5~10℃）能极显著提高蒙古扁桃种子发芽率和活力。低水势、高的混合盐胁迫、高温、种子浅的休眠及幼苗差的抗寒性是蒙古扁桃种群退化的原因，在拯救蒙古扁桃种群和人工驯化时，应选择有灌溉条件、春季气温低的区域育苗，建议土壤解冻时播种，利用早春的低温破除种子休眠，培育壮苗。

关键词: 蒙古扁桃(Amygdalus mongolica), 萌发, 逆境, 生态因子

Abstract: In order to investigate the causes of degradation and the difficult problems in seedlings breeding of Amygdalus mongolica, the response characteristics of the seed germination and seedling growth of Amygdalus mongolica to adverse ecological factors were investigated, using a method of indoor control of drought stress, mixed salt stress, variable temperatures and seed husking, with the seeds of A. mongolica in the middle section of the Qilian Mountain. The results showed insignificant difference in the germination rate (P>0.05) of the A. mongolica seeds processed in clean water for control and -0.15 MPa PEG solution, and significant sequential decrease in the germination rate (P<0.01) processed in the water potentials of -0.32, -0.54, and -0.81 MPa, and non-germination processed in -1.15 MPa, and non-germination processed in -1.15 MPa. As the drought worsened and water potential decreased, the germination was delayed, the germination and vitality indices, the primary bud rates, root lengths, number of secondary roots and fresh weights of seedlings were on a significantly decreasing trend (P<0.01). But the sound seedling index were significantly increased in case of treatment in -0.32 MPa. And the lowest thresholds of osmotic potential for seed germination was -0.81 MPa. The lowest mixed salt stress threshold for seed germination was 1.6%. Under light mixed salt stress (0.2%-0.4%), the length of primary buds and the number of secondary roots increased. With the increase in the mixed salt stress, the dry weight of primary buds and the fresh weight of seedlings were decreased, indicating that the seedlings responded and adapted to light mixed salt stress by reducing growth to promote root growth. After the stress of low osmotic potential or high-concentration mixed salt, a certain amount of the seeds developed into dormancy to maintain life force. The ungerminated seeds showed a germination rate of 62%-96% after rewatering, and the total of the primary germination rate and the re-germination rate was not different from the germination rate of the control seeds (P>0.05). The obstacle of seed coat is the main factor restricting seed germination. Seed dormancy can be interrupted by mechanical peeling. Stratification of seeds in low temperature (2-5℃) can significantly enhance seed vitality, and stratification in variable temperatures (5-10℃) can significantly improve the germination rate and vigor. The causes of degradation of A. mongolica include low water potential, high salt stress, high temperature, sensitive dormancy of seeds, and poor cold resistance of seedlings. For saving and manual breeding of A. mongolica, an area with irrigation conditions and of low temperature in spring should be selected for raising of seedlings, and sowing of seeds is suggested to occur at the time of soil thawing, to take advantage of the low temperature in early spring to and wake the seeds from their dormancy and cultivate strong seedlings.

Key words: Amygdalus mongolica, germination, adverse, ecological factors

中图分类号:

S330.3

王进, 颜霞, 李军元, 谢全刚, 张勇, 赵刚, 张成国. 蒙古扁桃(Amygdalus mongolica)种子萌发及幼苗生长对胁迫的响应[J]. 中国沙漠, 2018, 38(1): 140-148.

Wang Jin, Yan Xia, Li Junyuan, Xie Quangang, Zhang Yong, Zhao Gang, Zhang Chengguo. Response of the Seed Germination and Seedling Growth of Amygdalus mongolica to Stresses[J]. JOURNAL OF DESERT RESEARCH, 2018, 38(1): 140-148.

参考文献

[1] Miller T.Effects of emergence time on survival and growth in an early old-field plant community[J].Oecologia,1987,72:272-278.
[2] 张肖,王旭,焦培培,等.胡杨(Populus euphratica)种子萌发及胚生长对盐旱胁迫的响应[J].中国沙漠,2016,36(6):1597-1605.
[3] 曾幼玲,蔡忠贞,马纪.盐分和水分胁迫对两种盐生植物盐爪爪和和盐穗木种子萌发的影响[J].生态学杂志,2006,25(9):1014-1018.
[4] 高天鹏,王春燕,张勇,等.播种深度和土壤水分对黄花补血草种子萌发的影响[J].中国沙漠,2009,29(2):529-535.
[5] Maun M A.Adaptations of plants to burial in coastal sand dunes[J].Canadian Journal of Botany,1996,74:1322-1330.
[6] Omami E N,Haigh A M,Medd R W,et al.Changes in germinability,dormancy and viability of Amaranthus retroflexus as affected by depth and duration of burial[J].Weed Research,1999,39:345-354.
[7] 高瑞如,赵瑞华,张双凤,等.盐分和温度对盐节木种子萌发的影响[J].西北植物学报,2007,27(11):2281-2285.
[8] 王志才,牙库甫江\5阿西木,王艳,等.水盐胁迫对花花柴种子萌发的影响[J].中国沙漠,2012,32(5):750-755.
[9] Keiffer C W,Ungar I A.Germination responses of halophyte seeds exposed to prolonged hypersaline conditions[M]//Khan M A,Ungar I A.Biology of Salt Tolerant Plants.Karachi.Pakistan:Department of Botany,University of Karachi.1995:43-50
[10] 赵一之.蒙古扁桃的植物区系地理分布研究[J].内蒙古大学学报:自然科学版,1995,26(6):713-715.
[11] 陆玲娣.中国植物志[M].北京:科学出版社,1986:8-17.
[12] 王进,马国泰,宋涛,等.干旱、半干旱地区蒙古扁桃种子萌发对土壤水分和播种深度的响应特征[J].冰川冻土,2014,36(5):1313-1320.
[13] 方海涛,李俊兰,王黎元.珍稀濒危植物蒙古扁桃研究进展[J].阴山学刊,2004,18(2):16-18.
[14] 斯琴巴特尔,秀敏.蒙古扁桃种子萌发的生理生化特性[J].中国草地学报,2006,28(2):39-43.
[15] 戚康标,常弘,缪汝槐.中国珍稀濒危动物植物辞典[M].广州:广东人民出版社,2001(1):674.
[16] 红雨,邹林林,朱清芳. 濒危植物蒙古扁桃种子雨和土壤种子库特征[J].林业科学,2012,48(10):145-149.
[17] 曾彦军,王彦荣,萨仁,等.几种旱生灌木种子萌发对干旱胁迫的响应[J].应用生态学报,2002,13(8):953-956.
[18] 罗光宏,王进,颜霞,等.干旱胁迫对唐古特白刺(Nitraria tangutorum)种子吸胀萌发和幼苗生长的影响[J].中国沙漠,2014,34(6):1537-1543
[19] 李悦,陈志强,时瑞亭,等.不同白榆家系苗期耐盐碱综合评价[J].北京林业大学学报,2011(3):8-11.
[20] 王进,张勇,赵刚,等.蒙古扁桃种子萌发和幼苗生长对渗透胁迫的响应[J].干旱地区农业研究,2014,32(1):191-195.
[21] 曾彦军,王彦荣,庄光辉,等.红砂和霸王种子萌发对干旱与播深条件的响应[J].生态学报,2008(8):1629-1634.
[22] 石勇,刘源,殷恒霞,等.红砂(Reaumuria soongarica)种子萌发特性及其局部适应性[J]. 中国沙漠,2016,36(3):644-650.
[23] 王进,王桔红,张勇,等.苦豆子和披针叶黄华种子萌发和幼苗生长对干旱胁迫的响应[J].中国生态农业学报,2011,19(4)872-877.
[24] Michel B E,Kaufmann M R,The osmotic potential of polyethylene glycol 6000[J].Plant Physiology,1973,51:914-916.
[25] 闫治斌,秦嘉海,王爱勤,等.盐碱土改良材料对草甸盐土理化性质与玉米生产效益的影响[J].水土保持通报,2011,32(2):122-127.
[26] 尹燕枰,董学会.种子学实验技术[M]北京:中国农业出版社,1997:87-96.
[27] 颜启传,种子检验原理与技术[M]杭州:浙江大学出版社,2001:50-80.
[28] 国际种子检验协会.种苗评定与种子活力测定方法手册[M].徐本美、韩建国,等译.北京:北京农业大学出版社,1993:53-56.
[29] 胡晋.种子生物学[M].北京:高等教育出版社,2006:16.
[30] Zeng Y J,Wang Y R,Zhang J M.Is reduced seed germination due to water limitation a special survival strategy used by xerophytes in arid dunes?[J].Journal of Arid Environments,2010,74(4):508-511.
[31] 马闯,张文辉,刘新成.等渗的盐分和水分胁迫对红柳种子萌发的影响[J].植物研究,2008(4):465-470.
[32] 罗君,彭飞,王涛,等.黑果枸杞(Lycium ruthenicum)种子萌发及幼苗生长对盐胁迫的响应[J].中国沙漠,2017,37(2):264-267.