Germination of Dimorphic Seeds of the Desert Annual Halophyte Suaeda aralocaspica (Chenopodiaceae), a C4 Plant without Kranz Anatomy

作  者:Wang L, Huang ZY, Baskin CC, Baskin JM, Dong M
影响因子:2.939
刊物名称:Annals of Botany
出版年份:
卷:102  期:  页码:757–769

论文摘要:

Background and Aims Suaeda aralocaspica is a C4 summer annual halophyte without Kranz anatomy that isrestricted to the deserts of central Asia. It produces two distinct types of seeds that differ in colour, shape andsize. The primary aims of the present study were to compare the dormancy and germination characteristics ofdimorphic seeds of S. aralocaspica and to develop a conceptual model of their dynamics.† Methods Temperatures simulating those in the natural habitat of S. aralocaspica were used to test for primary dormancyand germination behaviour of fresh brown and black seeds. The effects of cold stratification, gibberellic acid,seed coat scarification, seed coat removal and dry storage on dormancy breaking were tested in black seeds.Germination percentage and recovery responses of brown seeds, non-treated black seeds and 8-week cold-stratifiedblack seeds to salt stress were tested.† Key Results Brown seeds were non-dormant, whereas black seeds had non-deep Type 2 physiological dormancy(PD). Germination percentage and rate of germination of brown seeds and of variously pretreated black seeds weresignificantly higher than those of non-pretreated black seeds. Exposure of seeds to various salinities had significanteffects on germination, germination recovery and induction into secondary dormancy. A conceptual model is presentedthat ties these results together and puts them into an ecological context.†Conclusions The two seed morphs of S. aralocaspica exhibit distinct differences in dormancy and germinationcharacteristics. Suaeda aralocaspica is the first cold desert halophyte for which non-deep Type 2 PD has beendocumented.
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