Adaptive strategies of dimorphic seeds of the desert halophyte Suaeda corniculata in saline habitat

doi:10.3724/SP.J.1258.2012.00781

Abstract

Abstract:

Aims Suaeda corniculata (Chenopodiaceae) is an annual halophyte in salt marshes and saline deserts of northern China. It produces two distinct types of seeds (brown and black). The primary aims of our study were to compare the morphology, dormancy and germination characteristics of dimorphic seeds of S. corniculata in order to elucidate adaptive strategies of the desert halophyte in stressful saline habitat.
Methods Seeds were collected in saline habitats in Otog, Nei Mongol. The dimorphic seeds were incubated in different temperature regimes, light and salinity (NaCl) conditions to determine their germination responses. The effects of cold stratification and seed coat scarification on dormancy breaking of black seeds were also tested.
Important findings Dimorphic seeds were different in seed mass and testa morphology. Brown seeds were bigger and more permeable to water than black seeds. Seed ratio was 5.6 : 1 (black seeds : brown seeds). Freshly matured brown seeds had a high germination percentage (84%-100%) in all temperature regimes and under either light or dark conditions. By contrast, black seeds had a lower germination percentage (8%-78%) than brown seeds in all temperature regimes, and germination was increased in light. Seed coat scarification, GA₃ treatments and cold stratification significantly increased the germination of black seeds, suggesting that black seeds had non-deep physiological dormancy. Responses of dimorphic seeds to saline stress were different. Brown seeds were more salt-tolerant than black seeds and germinated at a high germination percentage in high salt concentrations. Cold stratification reduced the sensitivity of black seeds to salt stress and increased the initial germination percentage, recovery and final germination in salt solutions. The differences in morphology, dormancy and germination characteristics between dimorphic seeds of S. corniculata increased the species’ fitness to heterogeneous habitats and formed an ecological adaptive strategy that may allow S. corniculata to successfully adapt to the harsh desert habitat.

Key words: desert halophyte, saline habitat, seed dimorphism, seed germination, seed physiological dormancy, Suaeda corniculata

YANG Fan, CAO De-Chang, YANG Xue-Jun, GAO Rui-Ru, HUANG Zhen-Ying. Adaptive strategies of dimorphic seeds of the desert halophyte Suaeda corniculata in saline habitat[J]. Chin J Plant Ecol, 2012, 36(8): 781-790.

Add to citation manager EndNote|Ris|BibTeX

URL: https://www.plant-ecology.com/EN/10.3724/SP.J.1258.2012.00781

https://www.plant-ecology.com/EN/Y2012/V36/I8/781

Figures/Tables 8

References 32

[1]	Bao SD (鲍士旦) (2000). Soil Agriculture and Chemistry Analysis (土壤农化分析). China Agriculture Press, Beijing. (in Chinese)
[2]	Baskin CC, Baskin JM (1998). Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination. Academic Press, San Diego.
[3]	Chen MZ (陈明忠), Sun K (孙坤), Zhang ML (张明理), Pang HL (庞海龙), Li JX (李金霞) (2011). Comparative study on micro-morphological characteristics of seed coat of fourteen species in Chenopodiaceae from China. Journal of Plant Resources and Environment (植物资源与环境学报), 20, 1-9. (in Chinese with English abstract)
[4]	de Clavijo ER (2005). The reproductive strategies of the heterocarpic annual Calendula arvensis (Asteraceae). Acta Oecologica, 28, 119-126.
[5]	Gutterman Y (1993). Seed Germination in Desert Plants. Springer-Verlag, New York.
[6]	Gutterman Y (2002). Survival Strategies of Annual Desert Plants. Springer, Berlin.
[7]	Harper JL, Lovell PH, Moore KG (1970). The shapes and sizes of seeds. Annual Review of Ecology and Systematics, 1, 327-356.
[8]	Imbert E (2002). Ecological consequences and ontogeny of seed heteromorphism. Perspectives in Plant Ecology, Evolution and Systematics, 5, 13-36.
[9]	Khan MA, Gul B, Weber DJ (2001). Germination of dimorphic seeds of Suaeda moquinii under high salinity stress. Australian Journal of Botany, 49, 185-192.
[10]	Kong XW (孔宪武), Jian ZP (简焯坡) (1979). Flora of China (中国植物志). Science Press, Beijing. (in Chinese)
[11]	Lev-Yadun S (2000). Why are underground flowering and fruiting more common in Israel than anywhere else in the world? Current Science, 79, 289.
[12]	Li L (李利), Yang XL (杨小林), Wang WH (王伟华) (2007). Response of germination of dimorphic seeds of Bors- zczowiz aralocaspica to habitat conditions. Arid Zone Research (干旱区研究), 24, 830-834. (in Chinese with English abstract)
[13]	Liu PW (刘鹏伟), Wei Y (魏岩) (2007). Seed dimorphism and germination behavior of Atriplex micrantha, an annual inhabiting Junggar desert. Acta Ecologica Sinica (生态学报), 27, 4233-4239. (in Chinese with English abstract)
[14]	Liu YF (刘艳芳), Wei Y (魏岩), Yan C (严成) (2009). Germination characteristics and ecological adaptation of dimorphic seeds of Borszczowia aralocaspica. Acta Ecologica Sinica (生态学报), 29, 6609-6614. (in Chinese with English abstract)
[15]	Lomonosova M, Brandt R, Freitag H (2008). Suaeda corniculata (Chenopodiaceae) and related new taxa from Eurasia. Willdenowia, 38, 81-109.
[16]	Lu JM (陆静梅), Li JD (李建东) (2007). The anatomical study in Suaedac corniculata (C. A. M.) Bunge. Journal of Northeast Normal University (Natural Science Edition) (东北师范大学学报 (自然科学版)), 23, 104-107. (in Chinese with English abstract)
[17]	Ma YQ (马毓泉) (1979). Flora of Inner Mongolia (内蒙古植物志). Inner Mongolia University Press, Hohhot. (in Chinese)
[18]	Mandák B, Pyšek P (2001a). The effects of light quality, nitrate concentration and presence of bracteoles on germination of different fruit types in the heterocarpous Atriplex sagittata. Journal of Ecology, 89, 149-158. DOI URL
[19]	Mandák B, Pyšek P (2001b). Fruit dispersal and seed banks in Atriplex sagittata: the role of heterocarpy. Journal of Ecology, 89, 159-165.
[20]	Mayer AM, Poljakoff-Mayer A (1989). The Germination of Seeds 4th edn. Pergamon Press, Oxford.
[21]	Mcevoy PB (1984). Dormancy and dispersal in dimorphic achenes of tansy ragwort, Senecio jacobaea L. (Compositae). Oecologia, 61, 160-168.
[22]	Qu XX (渠晓霞), Huang ZY (黄振英) (2005). The adaptive strategies of halophyte seed germination. Acta Ecologica Sinica (生态学报), 25, 2389-2398. (in Chinese with English abstract)
[23]	Sorensen AE (1978). Somatic polymorphism and seed dispersal. Nature, 276, 174-176.
[24]	Ungar IA (1987). Population ecology of halophyte seeds. The Botanical Review, 53, 301-334.
[25]	Venable DL (1985). The evolutionary ecology of seed heteromorphism. The American Naturalist, 126, 577-595.
[26]	Venable DL (2007). Bet hedging in a guild of desert annuals. Ecology, 88, 1086-1090.
[27]	Venable DL, Burquez A (1990). Quantitative genetics of size, shape, life-history, and fruit characteristics of the seed heteromorphic composite Heterosperma pinnatum. II. Correlation structure. Evolution, 44, 1748-1763.
[28]	Wang L (王雷), Dong M (董鸣), Huang ZY (黄振英) (2010). Review of research on seed heteromorphism and its ecological significance. Chinese Journal of Plant Ecology (植物生态学报), 34, 578-590. (in Chinese with English abstract)
[29]	Wang L, Huang ZY, Baskin CC, Baskin JM, Dong M (2008). Germination of dimorphic seeds of the desert annual halophyte Suaeda aralocaspica (Chenopodiaceae), a C₄ plant without Kranz anatomy. Annals of Botany, 102, 757-769.
[30]	Wei Y, Dong M, Huang ZY (2007). Seed polymorphism, dormancy and germination of Salsola affinis (Chenopodiaceae), a dominant desert annual inhabiting the Junggar Basin of Xinjiang, China. Australian Journal of Botany, 55, 464-470.
[31]	Wei Y, Dong M, Huang ZY, Tan DY (2008). Factors influencing seed germination of Salsola affinis (Chenop-odiaceae), a dominant annual halophyte inhabiting the deserts of Xinjiang, China. Flora, 203, 134-140.
[32]	Yao SX, Lan HY, Zhang FC (2010). Variation of seed heteromorphism in Chenopodium album and the effect of salinity stress on the descendants. Annals of Botany, 105, 1015-1025.

月份 Month	1月 Jan.	2月 Feb.	3月 Mar.	4月 Apr.	5月 May	6月 Jun.	7月 Jul.	8月 Aug.	9月 Sept.	10月 Oct.	11月 Nov.	12月 Dec.
最高气温 Maximum air temperature	-0.4	4.3	10.6	18.2	23.8	28.2	29.6	27.6	22.6	16.2	8.6	1.5
最低气温 Minimum air temperature	-16.4	-11.8	-4.3	2.7	9.0	13.8	16.5	14.8	9.0	1.4	-6.8	-14.1

月份 Month	1月 Jan.	2月 Feb.	3月 Mar.	4月 Apr.	5月 May	6月 Jun.	7月 Jul.	8月 Aug.	9月 Sept.	10月 Oct.	11月 Nov.	12月 Dec.
最高气温 Maximum air temperature	-0.4	4.3	10.6	18.2	23.8	28.2	29.6	27.6	22.6	16.2	8.6	1.5
最低气温 Minimum air temperature	-16.4	-11.8	-4.3	2.7	9.0	13.8	16.5	14.8	9.0	1.4	-6.8	-14.1

种子类型 Seed type	种皮特征 Testa characteristics	种子直径 Seed diameter (mm)	千粒重 Mass of 1000 seeds (mg)	黑色种子数:棕色种子数 Ratio of black seed to brown seed
棕色种子 Brown seed	膜质, 柔软, 无光泽 Membranous, soft and lusterless	1.07 ± 0.10^a	315.78 ± 1.75^a	5.60 ± 0.91
黑色种子 Black seed	角质, 硬脆, 有光泽 Keratose, hard, brittle and glossy	0.95 ± 0.08^b	240.35 ± 3.86^b	5.60 ± 0.91

种子类型 Seed type	种皮特征 Testa characteristics	种子直径 Seed diameter (mm)	千粒重 Mass of 1000 seeds (mg)	黑色种子数:棕色种子数 Ratio of black seed to brown seed
棕色种子 Brown seed	膜质, 柔软, 无光泽 Membranous, soft and lusterless	1.07 ± 0.10^a	315.78 ± 1.75^a	5.60 ± 0.91
黑色种子 Black seed	角质, 硬脆, 有光泽 Keratose, hard, brittle and glossy	0.95 ± 0.08^b	240.35 ± 3.86^b	5.60 ± 0.91

	盐度 Salinity (mol·L^-1)	初始萌发率 Initial germination (%, mean ± SE)	萌发恢复率 Germination recovery percentage (%, mean ± SE)	最终萌发率 Final germination (%, mean ± SE)	有生活力的种子 Viable seed (%, mean ± SE)	有生活力但未萌发的种子 Viable ungerminated seed (%, mean ± SE)
新成熟的黑色种子 Freshly matured black seed	0.0	58 ± 2^a	0^c	58 ± 2^a	100^a	42 ± 2^c
	0.1	16 ± 2^b	7 ± 3^b	22 ± 4^bc	100^a	78 ± 4^ab
	0.2	2 ± 2^c	7 ± 2^b	9 ± 2^c	100^a	91 ± 2^a
	0.5	1 ± 1^c	27 ± 3^a	28 ± 3^b	100^a	72 ± 3^b
	0.8	0^c	20 ± 2^ab	20 ± 2^bc	100^a	80 ± 2^ab
	1.0	0^c	32 ± 8^a	32 ± 8^b	100^a	68 ± 8^b
8周低温层积的黑色种子 Black seed after 8 weeks cold stratification	0.0	95 ± 3^a	0^c	95 ± 3^a	100^a	5 ± 3^b
	0.1	42 ± 11^b	0^c	42 ± 11^b	100^a	58 ± 11^a
	0.2	33 ± 5^bc	10 ± 3^b	40 ± 3^b	100^a	60 ± 3^a
	0.5	15 ± 6^cd	37 ± 10^a	45 ± 12^b	100^a	55 ± 12^a
	0.8	0^d	24 ±3^ab	24 ± 3^b	100^a	76 ± 3^a
	1.0	0^d	33 ± 5^a	33 ± 5^b	100^a	67 ± 5^a
新成熟的棕色种子 Freshly matured brown seed	0.0	100^a	--	100^a	100^a	0^b
	0.1	100^a	--	100^a	100^a	0^b
	0.2	100^a	--	100^a	100^a	0^b
	0.5	76 ± 7^b	96 ± 23^a	98 ± 1^a	100^a	1 ± 1^b
	0.8	42 ± 4^c	93 ± 1^a	96 ± 1^b	100^a	4 ± 1^a
	1.0	12 ± 2^d	92 ± 2^a	93 ± 2^b	100^a	7 ± 2^a