Distyly and heteromorphic self-incompatibility of Hedyotis pulcherrima (Rubiaceae)

doi:10.3724/SP.J.1003.2012.11243

Abstract

Abstract:

Heterostyly is a genetically controlled floral polymorphism, which includes both distyly and tristyly. We investigated morph ratio, floral and pollen morphology, and self-incompatibility of Hedyotis pulcherrima. Overall, the natural population of H. pulcherrima was isoplethic, containing long-styled and short-styled morphs with an equilibrium 1:1 ratio. Long-styled and short-styled morph exhibited a precise reciprocal herkogamy, which was significantly correlated with corolla length. Stigma-lobe length, pollen size, and starch content in pollen grains were dimorphic in the two morphs of H. pulcherrima, whereas pollen germination and pollen tube growth in vitro were not significantly different between the two morphs. Artificial pollination revealed that pollen tube shape was normal in both morphs where pollen tubes reached the ovary 24 h after pollination. However, pollen tube growth was arrested in the stigma with the accumulation of callose in the swollen tips in two morphs with self and intramorph pollination, indicating strict heteromorphic self-incompatibility in H. pulcherrima. No fruit was produced in emasculated netted flowers, suggesting the absence of apomixis. Artificial intermorph pollination resulted in 100% of fruit set, significantly higher than those with open pollination. Our results indicate that H. pulcherrima is a typically distylous species with heteromorphic self-incompatibility.

Key words: distyly, Hedyotis pulcherrima, heteromorphic self-incompatibility, breeding system

Xinxin Liu, Xiaoqin Wu, Dianxiang Zhang. Distyly and heteromorphic self-incompatibility of Hedyotis pulcherrima (Rubiaceae)[J]. Biodiv Sci, 2012, 20(3): 337-347.

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URL: https://www.biodiversity-science.net/EN/10.3724/SP.J.1003.2012.11243

https://www.biodiversity-science.net/EN/Y2012/V20/I3/337

Figures/Tables 9

References 38

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花部和花粉特征 Floral and pollen attributes	长花柱型 Long-styled morph (n = 30)	短花柱型 Short-styled morph (n = 30)	t-检验 t-test
花冠长度 Corolla length (mm)	18.34±1.21	18.55±1.65	0.56
柱头高度 Stigma height (mm)	15.13±0.94	11.18±1.03	15.47^**
花柱长度 Style height (mm)	13.61±0.89	8.60±0.82	61.63^**
柱头裂片长度 Stigma lobe length (mm)	1.63±0.25	2.83±0.46	12.48^**
花药高度 Anther height (mm)	11.12±0.76	14.62±1.27	12.94^**
花药长度 Anther length (mm)	2.11±0.18	2.38±0.16	6.10^**
花丝长度 Filament length (mm)	0.42±0.11	1.22±0.14	24.93^**
花丝基部至花冠基部距离 From filament attachment to the base of corolla (mm)	9.84±0.70	12.42±1.28	9.69^**
花丝基部至花冠顶端距离 From filament attachment to the apex of corolla (mm)	8.31±0.65	6.25±0.66	12.15^**
子房高度 Ovary height (mm)	2.11±0.19	2.22±0.26	1.83^*
花粉数 No. of pollen grains per flower	8,980±144.05	7,988±181.85	9.56^**
胚珠数 No. of ovules per flower	79.2±6.75	83.6±5.78	2.09^*
花粉/胚珠比 P/O ratio	113.51±6.88	95.59±1.43	10.75^**
花粉极轴长度 Polar axis of pollen (P) (μm)	24.89±1.42	27.18±2.16	4.85^**
花粉赤道长度 Equatorial axis of pollen (E) (μm)	23.38±1.65	25.02±1.35	4.2^**
花粉极轴长/赤道轴长 (P/E)	1.05±0.06	1.03±0.07	1.19
网孔直径 Diameter of lumina (μm)	0.56±0.11	0.51±0.08	0.39

花部和花粉特征 Floral and pollen attributes	长花柱型 Long-styled morph (n = 30)	短花柱型 Short-styled morph (n = 30)	t-检验 t-test
花冠长度 Corolla length (mm)	18.34±1.21	18.55±1.65	0.56
柱头高度 Stigma height (mm)	15.13±0.94	11.18±1.03	15.47^**
花柱长度 Style height (mm)	13.61±0.89	8.60±0.82	61.63^**
柱头裂片长度 Stigma lobe length (mm)	1.63±0.25	2.83±0.46	12.48^**
花药高度 Anther height (mm)	11.12±0.76	14.62±1.27	12.94^**
花药长度 Anther length (mm)	2.11±0.18	2.38±0.16	6.10^**
花丝长度 Filament length (mm)	0.42±0.11	1.22±0.14	24.93^**
花丝基部至花冠基部距离 From filament attachment to the base of corolla (mm)	9.84±0.70	12.42±1.28	9.69^**
花丝基部至花冠顶端距离 From filament attachment to the apex of corolla (mm)	8.31±0.65	6.25±0.66	12.15^**
子房高度 Ovary height (mm)	2.11±0.19	2.22±0.26	1.83^*
花粉数 No. of pollen grains per flower	8,980±144.05	7,988±181.85	9.56^**
胚珠数 No. of ovules per flower	79.2±6.75	83.6±5.78	2.09^*
花粉/胚珠比 P/O ratio	113.51±6.88	95.59±1.43	10.75^**
花粉极轴长度 Polar axis of pollen (P) (μm)	24.89±1.42	27.18±2.16	4.85^**
花粉赤道长度 Equatorial axis of pollen (E) (μm)	23.38±1.65	25.02±1.35	4.2^**
花粉极轴长/赤道轴长 (P/E)	1.05±0.06	1.03±0.07	1.19
网孔直径 Diameter of lumina (μm)	0.56±0.11	0.51±0.08	0.39

	花冠长度 Corolla length	柱头高度 Stigma height	花柱长度Style height	柱头裂片长度Stigma lobe length	花药高度 Anther height	花药长度 Anther length	花丝长度Filament length	花丝基部至花冠基部距离 From filament attachment to the base of corolla	花丝基部至花冠顶端距离From filament attachment to the apex of corolla
长花柱型 Long-styled morph
柱头高度 Stigma height	0.566^**
花柱长度 Style height	0.501^**	0.935^**
柱头裂片长度 Stigma lobe length	0.373^*	0.540^**	0.206
花药高度 Anther height	0.796^**	0.452^*	0.417^*	0.257
花药长度 Anther length	0.278	0.344	0.196	0.483^**	0.248
花丝长度 Filament length	0.475^**	0.261	0.286	0.040	0.368^*	0.184
花丝基部至花冠基部距离 From filament attachment to the base of corolla	0.836^**	0.391^*	0.327	0.301	0.934^**	0.231	0.323
花丝基部至花冠顶端距离 From filament attachment to the apex of corolla	0.723^**	0.442^*	0.429^*	0.202	0.377^*	0.319	0.325	0.411^*
子房高度 Ovary height	0.510^**	0.533^**	0.498^**	0.290	0.263	0.203	0.492^**	0.199	0.495^**
短花柱型 Short-styled morph
柱头高度 Stigma height	0.723^**
花柱长度 Style height	0.606^**	0.873^**
柱头裂片长度 Stigma lobe length	0.490^**	0.623^**	0.162
花药高度 Anther height	0.825^**	0.620^**	0.583^**	0.319
花药长度 Anther length	-0.206	0.056	0.058	0.020	-0.109
花丝长度 Filament length	0.135	0.080	0.085	0.025	0.059	-0.379^*
花丝基部至花冠基部距离 From filament attachment to the base of corolla	0.902^**	0.732^**	0.620^**	0.486^**	0.875^**	-0.238	0.154
花丝基部至花冠顶端距离 From filament attachment to the apex of corolla	0.748^**	0.492^**	0.391^*	0.369^*	0.426^*	-0.276	0.297	0.493^**
子房高度 Ovary height	0.336	0.307	0.250	0.221	0.046	0.091	0.125	0.097	0.501^**

	花冠长度 Corolla length	柱头高度 Stigma height	花柱长度Style height	柱头裂片长度Stigma lobe length	花药高度 Anther height	花药长度 Anther length	花丝长度Filament length	花丝基部至花冠基部距离 From filament attachment to the base of corolla	花丝基部至花冠顶端距离From filament attachment to the apex of corolla
长花柱型 Long-styled morph
柱头高度 Stigma height	0.566^**
花柱长度 Style height	0.501^**	0.935^**
柱头裂片长度 Stigma lobe length	0.373^*	0.540^**	0.206
花药高度 Anther height	0.796^**	0.452^*	0.417^*	0.257
花药长度 Anther length	0.278	0.344	0.196	0.483^**	0.248
花丝长度 Filament length	0.475^**	0.261	0.286	0.040	0.368^*	0.184
花丝基部至花冠基部距离 From filament attachment to the base of corolla	0.836^**	0.391^*	0.327	0.301	0.934^**	0.231	0.323
花丝基部至花冠顶端距离 From filament attachment to the apex of corolla	0.723^**	0.442^*	0.429^*	0.202	0.377^*	0.319	0.325	0.411^*
子房高度 Ovary height	0.510^**	0.533^**	0.498^**	0.290	0.263	0.203	0.492^**	0.199	0.495^**
短花柱型 Short-styled morph
柱头高度 Stigma height	0.723^**
花柱长度 Style height	0.606^**	0.873^**
柱头裂片长度 Stigma lobe length	0.490^**	0.623^**	0.162
花药高度 Anther height	0.825^**	0.620^**	0.583^**	0.319
花药长度 Anther length	-0.206	0.056	0.058	0.020	-0.109
花丝长度 Filament length	0.135	0.080	0.085	0.025	0.059	-0.379^*
花丝基部至花冠基部距离 From filament attachment to the base of corolla	0.902^**	0.732^**	0.620^**	0.486^**	0.875^**	-0.238	0.154
花丝基部至花冠顶端距离 From filament attachment to the apex of corolla	0.748^**	0.492^**	0.391^*	0.369^*	0.426^*	-0.276	0.297	0.493^**
子房高度 Ovary height	0.336	0.307	0.250	0.221	0.046	0.091	0.125	0.097	0.501^**

处理方式 Treatment	结实率 Fruit sets (%)		t-检验 t-test
处理方式 Treatment	长花柱型 Long-styled morph	短花柱型 Short-styled morph	t-检验 t-test
自交 Self-pollination	0 (n = 35)	0 (n = 52)	–
型内异交 Intramorph pollination	0 (n = 37)	0 (n = 30)	–
型间异交 Intermorph pollination	100 (n = 31)	100 (n = 29)	–
去雄套袋 Netting with emasculation	0 (n = 83)	0 (n = 63)	–
自然套袋 Netting without emasculation	0 (n = 53)	0 (n = 54)	–
自然 Open pollination	70.2±16.2 (n = 58)	68.2±21.3 (n = 93)	0.08