Genetic diversity and population structure of Hibiscus aridicola, an endangered ornamental species in dry-hot valleys of Jinsha River

doi:10.1016/j.pld.2019.07.001

Abstract

Abstract: Hibiscus aridicola is an endangered ornamental shrub of the family Malvaceae that is endemic to the dryhot valleys of Jinsha River in southwestern China. This species is a typical plant species with extremely small populations (PSESP). To support and monitor future conservation, develop management measures, and genotype this species, we performed extensive field studies together with genetic analyses. Specifically, we screened eleven microsatellite loci of 69 individuals of H. aridicola from four accessions. The population genetics analyses indicated that H. aridicola possesses high genetic diversity at both the population (0.6962-0.7293) and species level (0.7837) compared to other endemic/endangered species in China. The low differentiation of populations (Fst=0.0971) and the high gene flow between populations of H. aridicola (Nm=2.3236) could be due to its distribution along rivers in the hot-valleys of the Jinsha River and the wind-mediated dispersal of its seeds. Furthermore, the genetic diversity of H. aridicola is slightly positively correlated with geographic distance. Two populations are undergoing a genetic bottleneck, and require more specific attention from conservationists. Additionally, our analyses of the population genetics of H. aridicola demonstrate that the declines in populations are not the result of the internal genetics of these populations but due to external human activities over the past decades.

Key words: Malvaceae, Hibiscus aridicola, Population genetics, Conservation, Endemic species, PSESP

Xin Zhang, Le Zhang, Johann Schinnerl, Wei-Bang Sun, Gao Chen. Genetic diversity and population structure of Hibiscus aridicola, an endangered ornamental species in dry-hot valleys of Jinsha River[J]. Plant Diversity, 2019, 41(05): 300-306.

Figures/Tables 8

References 22

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类别 Classification	柽柳灌丛 Tamarix thickets	胡杨疏林 Populus euphratica woodlands	沙地 Sand lands	农田 Farmlands	水体 Water bodies	芦苇草地 Phragmites australis grasslands	总和 Total	制图精度(%) Mapping accuracy
柽柳灌丛 Tamarix thickets	9 982	3 121	1 375	102	48	160	14 788	67.5
胡杨疏林 Populus euphratica woodlands	6 403	23 758	413	30	91	523	31 218	76.1
沙地 Sand lands	1 424	228	38 380	0	21	1	40 054	95.8
农田 Farmlands	8	13	0	9 881	1	33	9 936	99.4
水体 Water bodies	0	0	0	0	58 371	14	58 385	99.9
芦苇草地 Phragmites australis grasslands	569	1 658	23	858	2 110	15 964	21 182	75.4
综合 Total	18 386	28 778	40 191	10 871	60 642	16 695	175 563	—
用户精度 User accuracy (%)	54.3	82.6	95.5	90.9	96.3	95.6	—	—
总精度 Total accuracy = 89.0%; Kappa系数 Kappa coefficient = 0.86

类别 Classification	柽柳灌丛 Tamarix thickets	胡杨疏林 Populus euphratica woodlands	沙地 Sand lands	农田 Farmlands	水体 Water bodies	芦苇草地 Phragmites australis grasslands	总和 Total	制图精度(%) Mapping accuracy
柽柳灌丛 Tamarix thickets	9 982	3 121	1 375	102	48	160	14 788	67.5
胡杨疏林 Populus euphratica woodlands	6 403	23 758	413	30	91	523	31 218	76.1
沙地 Sand lands	1 424	228	38 380	0	21	1	40 054	95.8
农田 Farmlands	8	13	0	9 881	1	33	9 936	99.4
水体 Water bodies	0	0	0	0	58 371	14	58 385	99.9
芦苇草地 Phragmites australis grasslands	569	1 658	23	858	2 110	15 964	21 182	75.4
综合 Total	18 386	28 778	40 191	10 871	60 642	16 695	175 563	—
用户精度 User accuracy (%)	54.3	82.6	95.5	90.9	96.3	95.6	—	—
总精度 Total accuracy = 89.0%; Kappa系数 Kappa coefficient = 0.86

类别 Classification	像元数 Number of pixels	面积 Area (km²)
柽柳灌丛 Tamarix thickets	450 293	405.3
胡杨疏林 Populus euphratica woodlands	373 813	336.4
芦苇草地 Phragmites australis grasslands	316 968	285.3
水体 Water bodies	159 345	143.4

类别 Classification	像元数 Number of pixels	面积 Area (km²)
柽柳灌丛 Tamarix thickets	450 293	405.3
胡杨疏林 Populus euphratica woodlands	373 813	336.4
芦苇草地 Phragmites australis grasslands	316 968	285.3
水体 Water bodies	159 345	143.4

	像元数 Number of pixels	最小值 Minimum	最大值 Maximum	众数 Mode	平均值 Average	标准偏差 Standard deviation	变异系数 Coefficient of variation (%)
柽柳灌丛 Tamarix thickets	450 293	0.005	1.653	0.182	0.253	0.158	62.3
胡杨疏林 Populus euphratica woodlands	373 813	0.007	1.849	0.102	0.252	0.178	70.5