A STATISTICAL COMPARISON OF ANATOMICAL FEATURES IN SOME Ornithogalum SP. SPECIES¹

Comparação Estatística das Características Anatômicas em Espécies de Ornithogalum sp.

ABSTRACT

In the present study, Ornithogalum narbonense, O. montanum, O. wiedemannii, O. sigmoideum and O. lanceolatum species were compared statistically with respect to anatomical characters. Some differences were found in root, stem and leaf anatomy of the species. These differences and similarities were indicated in this study. A big metaxylem was present in all root cross sections, except for O. lanceolatum, which has three metaxylema. 2-3 layered annular type collenchyma were present in all species. Aerenchyma is present in all mesophiles.

Keywords:
statistic; Ornithogalum; anatomy

RESUMO

No presente estudo, as espécies Ornithogalum narbonense, O. montanum, O. wiedemannii, O. sigmoideum e O. lanceolatum, foram comparadas estatisticamente com relação às suas características anatômicas. Foram observadas diferenças na anatomia da raiz, caule e folhas das espécies. Estas diferenças e semelhanças foram indicadas no presente estudo. Foi observado um grande metaxilema em todas as seções da raiz, com exceção de O. lanceolatum, que possui três metaxilemas. Duas a três camadas de colênquima foram encontradas em todas as espécies. Todas as espécies mesófilas continham aerênquima.

Palavras-chave:
estatística; Ornithogalum; anatomia

INTRODUCTION

The genus Ornithogalum belonging to Hyacinthaceae family contains over 140 species widespread around the world. The genus is mostly spread in South Africa and around the Mediterranean (Uysal et al., 2005). Ornithogalum is represented by 45 species in the flora of Turkey and 17 of these species are endemic (Cullen, 1984; Davis et al., 1988; Ozhatay, 2000; Uysal et al., 2005; Varol, 2008; Dalg1c et al., 2009). Ornithogalum is a taxonomically difficult genus, while its morphology is poorly correlated with the variation in chromosome number and karyotype (Dalg1c and Özhatay, 1997). Since several decades, this taxonomically extremely difficult genus was the object of several studies on bulb structure and germination-type (Zahariadi, 1962, 1965; Speta, 1990, 1990a), classical cytotaxonomy (Peruzzi and Passalacqua, 2002; Garbari et al., 2003; Tornadore et al., 2003; Aquaro and Peruzzi, 2006), karyotype evolution (van Raamsdonk, 1986), chemotaxonomy (Øvstedal, 1991), morphometry (Moret et al., 1991; Øvstedal, 1991; Raamsdonk and Heringa, 1987; Moret, 1992; Moret and Galland, 1992; Coskuncelebi et al., 2002), seed micromorphology (Coskuncelebi, et al., 2000). In this study, Ornithogalum narbonense, O. montanum, O. wiedemannii, O. sigmoideum and O. lanceolatum species were compared statistically regarding their anatomical characters.

MATERIAL AND METHODS

Materials were collected from B1 Manisa Spil Mountain. Specimens were kept in the herbarium at Celal Bayar University. A morphological illustration of the plant taxon was made from fresh and dry specimens follewed "Flora of Turkey" volume 8 (Davis, 1984). For anatomical studies, the plant specimens were fixed in 70% ethanol. Hand cuts were stained with sartur reactive and safranin. Preparates were photographed with a motorized Leica DM 3000 microscope. Measurements were taken using ocularmicrometer of root, stem and leaf cell sizes of the species. Minimum, maximum, mean and standart deviations were determined.

For the numerical analysis, 16 anatomical characters were selected. This selection was based on the variations of the anatomical data. Characters were coded as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 and the taxa were coded as A, B, C, D, E. Significance of the differences between the taxa and characters were evaluated by Analysis of variance (Regression Analysis) and Pearson's correlation. The differences were assessed by the one-way ANOVA test. Pearson's correlation coefficients were also calculated. Statistical analysis were performed using the MINITAB software package.

RESULTS AND DISCUSSION

Anatomical findings

Roots

O. narbonense and O. lanceolatum species have two layered epidermis. Other species have one layered epidermis. Cortex is 3-5, 3-4, 7-11, 6-8, 4-5 layered in O. narbonense, O. montanum, O. wiedemannii, O. sigmoedeum and O. lanceolatum, respectively. Four-sided endodermis wall thickening was present in O. narbonense, O. montanum and O. sigmoedeum. A big metaxylem was present in all root cross sections except for O. lanceolatum, which has three metaxylema. 4-5 xylem strands were present in all roots.

Stems

A thick cuticle surrounds the one layered epidermis in all stem cross sections. The cortex consists of circle shaped cells in all species and 4-5, 5-6, 2-3, 5-6, 4-5 layered in O. narbonense, O. montanum, O. wiedemannii, O. sigmoedeum, and O. lanceolatum, respectively. 2-3 layered annular type collenchyma were present in all species. Vascular bundles are arranged in two rows in O. narbonense and O. montanum, three rings in O. wiedemannii, O. sigmoedeum, and O. lanceolatum. Raphide crystals were present in the stem cortex of O. sigmoedeum.

Leaves

In all species, the cuticle is present on both sides of the leaf. O. narbonense, O. wiedemannii and O. lanceolatum leaves have 1-2 layered palisade parenchyma under adaxial and abaxial epidermis and 2-3 layered spongy parenchyma. Palisade spongy separation was absent in O. montanum and O. sigmoedeum species. Mesophiles of all species have aerenchyma. O. lanceolatum mesophill have bigger aerenchyma than others.

Statistical analysis

The anatomical measuments of the investigated taxa are shown in Table 1. Significance of the differences between the Ornithogalum taxa was evaluated by analysis of variance (Regression Analysis) and Pearson's correlation (Correlation). The statistical analysis of the results are shown in Tables 2, 3, 4, 5and 6.

Table 1
Anatomical measurements of the species

O. narbonense	Min.-Max .	Ort±S.D	O. lanceolatum	Min.-Max.	Ort±S.D
Root			Root
Epidermis Width	20-50	35±13	Epidermis Width	38-52	47.5±6.4
Epidermis Length	15-50	30±12	Epidermis Length	30-50	42±8
Cortex (diameter)	70-23	140±62	Cortex (diameter)	30-170	100±99
Endodermis Width	18-23	21±1.8	Endodermis Width	12-22	17.8±3.7
Endodermis Length	10-15	12±1.8	Endodermis Length	7-12	10±1.7
Pericycle Width	15-18	17±1.2	Pericycle Width	15-26	21±4.6
Metaxylem ( diameter )	25-63	38±13	Metaxylem (diameter)	15-26	21±4.6
Stem			Stem
Epidermis Width	13-25	17±2.5	Epidermis Width	18-22	20±1.6
Epidermis Length	30-43	35±4.3	Epidermis Length	18-23	20.6±2
Cortex (diameter)	3-50	48±9.7	Cortex (diameter)	20-70	45±14.5
Trachea (diameter)	8-23	19±2.5	Trachea (diameter)	10-15	12±2.7
Leaf			Leaf
Abaxial epidermis Width	38-50	44±5.6	Abaxial epidermis Width	10-22	20±0.8
Abaxial epidermis Length	20-28	26±3.3	Abaxial epidermis Length	25-30	29±2.2
Palisade Length	28-40	34±4.7	Palisade Length	20-25	22.8±2.16
Adaxial epidermis Width	18-25	22±2.5	Adaxial epidermis Width	12-25	18.8± 4.5
Adaxial epidermis Length	30-38	34±2.5	Adaxial epidermis Length	12-20	16±4
O. sigmoideum	Min.-Max .	Ort±S.D	O. wiedemannii var. wiedemannii	Min.-Max.	Ort±S.D
Root			Root
Epidermis Width	15-38	24.5±9.8	Epidermis Width	10-20	15±5
Epidermis Length	20-50	32±13.8	Epidermis Length	20-40	30±10
Cortex (diameter)	10-35	25±10	Cortex (diameter)	22-10	16±6
Endodermis Width	18-23	20.6±2	Endodermis Width	5-15	9.6±5
Endodermis Length	11-18	14.6±3.5	Endodermis Length	10-18	13±3
Pericycle Width	10-18	15±3.4	Pericycle Width	15-25	20±5
Metaxylem (diameter)	35-40	38±2.1	Metaxylem (diameter)
Stem			Stem	30-38	34±3
Epidermis Width	20-35	26±6.5	Epidermis Width	25-30	26.5±2
Epidermis Length	30-40	37±4.4	Epidermis Length	28-88	72±22
Cortex (diameter)	35-110	64±31	Cortex (diameter)	25-38	33.5±5
Trachea (diameter)	15-30	23±6.7	Trachea (diameter)
Leaf			Leaf	15-23	20±5.1
Abaxial epidermis Width	25-40	32.5±6.4	Abaxial epidermis Width	15-20	17.5±2
Abaxial epidermis Length	20-25	23±2.4	Abaxial epidermis Length	63-70	66±2.8
Palisade Length	40-170	83.5±59	Palisade Length	12-25	19±4.8
Adaxial epidermis Width	13-20	16.3±3	Adaxial epidermis Width	15-22.5	17±3.2
Adaxial epidermis Length	20-27	23±2.6	Adaxial epidermis Length	10-20	15±5
O. montanum	Min.-Max .	Ort±S.D
Root	20-45	37±9.7
Epidermis Width	10-30	24±9
Epidermis Length	40-60	53±8.3
Cortex (diameter)	13-15	14±0.9
Endodermis Width	7-10	8.5±1.2
Endodermis Length	9-11	10±0.8
Pericycle Width	20-32	27±0.4
Metaxylem (diameter)
Stem	15-20	17±2.5
Epidermis Width	10-25	19±6.2
Epidermis Length	15-40	33.6±16
Cortex (diameter)	3-15	7.6±4.8
Trachea (diameter)
Leaf	10-28	20±7.5
Abaxial epidermis Width	20-40	27.5±8.6
Abaxial epidermis Length	38-15	33±3
Palisade Length	15-28	22±5
Adaxial epidermis Width	30-42	38±4.5
Adaxial epidermis Length	20-45	37±9.7

Table 2
Pearson's correlation (Correlation) based on anatomical characters of the investigated taxa

Features	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
1	0.607
	0.278
2	0.962	0.744
	0.009**	0.150
3	0.948	0.691	0.947
	0.014	0.196	0.015*
4	0.041*	0.798	0.204	0.220
	0.948	0.106	0.742	0.722
5	0.343	0.244	-0.138	0.055	0.565
	0.572	0.692	0.825	0.930	0.320
6	0.962	0.396	0.894	0.851	0.222	0.492
	0.009**	0.510	0.041*	0.068	0.720	0.400
7	0.874	0.721	0.872	0.745	0.221	0.456	0.819
	0.053	0.169	0.054	0.149	0.721	0.441	0.090
8	0.649	0.858	0.693	0.808	0.703	0.249	0.421	0.564
	0.236	0.063	0.194	0.098	0.186	0.686	0.480	0.322
9	0.751	0.415	0.667	0.869	0.118	0.011*	0.649	0.414	0.773
	0.144	0.487	0.219	0.056	0.850	0.985	0.236	0.488	0.126
10	0.873	0.622	0.778	0.857	0.241	0.371	0.762	0.795	0.797	0.820
	0.053	0.262	0.121	0.064	0.696	0.539	0.134	0.108	0.107	0.089
11	0.975	0.542	0.917	0.856	0.045	0.517	0.970	0.927	0.525	0.620	0.847
	0.005	0.345	0.028*	0.064	0.942	0.372	0.006**	0.023*	0.363	0.264	0.070
12	0.791	0.173	0.610	0.755	0.237	0.496	0.791	0.527	0.500	0.870	0.854	0.760
	0.111	0.781	0.274	0.140	0.701	0.395	0.111	0.362	0.391	0.055	0.066	0.136
13	0.910	0.730	0.928	0.800	0.194	0.382	0.863	0.988	0.570	0.451	0.770	0.944	0.528
	0.032	0.162	0.023*	0.104	0.755	0.526	0.060	0.002**	0.316	0.446	0.128	0.016*	0.361
14	0.737	0.959	0.804	0.809	0.700	0.082	0.533	0.785	0.937	0.614	0.814	0.672	0.429	0.781
	0.155	0.010*	0.101	0.097	0.188	0.896	0.355	0.116	0.019*	0.270	0.094	0.214	0.471	0.119
15	0.932	0.848	0.976	0.953	0.385	0.066	0.811	0.873	0.825	0.707	0.843	0.874	0.600	0.910	0.913
	0.021*	0.070	0.005**	0.012*	0.522	0.915	0.096	0.053	0.085	0.182	0.073	0.053	0.285	0.032*	0.030*

• * Significant at the level of 0.05. ** Significant at the level of 0.01.

Table 3
Pearson correlation (Correlation) based on 8 anatomical characters of the leaves of the investigated taxa

Characters	A	B	C	D
B	0.362
	0.140
C	0.006**	0.573
	0.979	0.013*
D	0.007**	0.483	0.749
	0.978	0.042*	0.008**
E	0.029*	0.194	0.430	0.030*
	0.910	0.441	0.075	0.906

• O. narbonense (A), O. lanceolatum (B), O. sigmoideum (C), O. wiedemannii (D), O. montanum (E), O. wiedemannii (D), O. montanum (E).

Table 4
Comparison anatomical features of the investigated taxa with Minitab

Takson	1	2	3	4	5	6	7	8
1	0.582
	0.303
2	0.546	0.998
	0.341	0.010**
3	0.957	0.768	0.736
	0.010**	0.130	0.156
4	0.873	0.516	0.472	0.841
	0.053	0.373	0.422	0.074
5	0.759	0.932	0.925	0.852	0.688
	0.136	0.021*	0.024*	0.067	0.199
6	-0.057	0.458	0.447	0.202	0.028	0.136
	0.927	0.438	0.450	0.744	0.965	0.827
7	0.996	0.613	0.576	0.967	0.909	0.780	-0.007
	0.020*	0.272	0.310	0.007**	0.032	0.120	0.991
8	0.865	0.547	0.537	0.787	0.619	0.778	-0.382	0.833
	0.058	0.340	0.351	0.114	0.265	0.121	0.526	0.080

Table 5
Comparison anatomical features of the investigated taxa with Pearson's correlation analysis

Taxa	C1	C2	C3	C4
C2	0.631
	0.009
C3	0.211	0.503
	0.433	0.047*
C4	0.125	0.192	0.177
	0.644	0.476	0.511
C5	0.621	0.730	0.143	0.103
	0.010*	0.001**	0.597	0.705

The differences among the investigated taxa are shown as A-C, A-D, A-E, B-C, B-D, DE and C-D in Table 3 and Table 5, and they are significant at level of 0.01P and 0.05P. According to Table 4 and Table 6, based on the Pearson's correlation method (Correlation), there are important correlations among the anatomical characters of the investigatigated taxa, shown as (Table 2) 1-3, 1-5, 1-7, 1-16, 215, 3- 4, 3-7, 3-12, 3-14, 3-16, 4-16, 6-10, 7-12, 8-12, 8-14, 9-15, 11-13 and 14 -15 at levels of 0.01P and 0.05P.

The results of the statistical analysis are shown in Tables 4 and 6. It was found that there were statistically important differences at levels of 0.01P and 0.05P.

Table 6
Comparison anatomical features of the investigated taxa with Minitab

Figure 1
Root cross sections; A:O. narbonense, B:O. montanum, C:O. wiedemannii, D,E: O.sigmoedeum, F:O. lanceolatum; co: cortex, en: endodermis, ep:epidermis, m:metaxylem, p:pericycle; scale bar 50 μm.

Figure 2
Stem cross sections; A:O. narbonense, B:O. montanum, C,D:O. wiedemannii, E: O.sigmoedeum, F:O. lanceolatum; co: cortex, cl:collenchyma, ep:epidermis, rc:raphide crystals, vb:vascular bundle; scale bar 50 μm.

Figure 3
Leaf cross sections; A:O. narbonense, B:O. montanum, C: O.sigmoedeum, D:O. lanceolatum; ab: abaxial epiderm

In the present study, five Ornithogalum taxa were compared statistically regarding anatomical characters. We aimed to find statistical and anatomical differences in addition to morphological characters to distinguish these species. Anatomical features of the root of the five species are similar. O. lanceolatum have three metaxylema in the root while others have one metaxylem. Scape has a single layered epidermis with a thin cuticle in all taxa. In most species of the subfamily Ornithogaloideae, vascular bundles are in two rows and large bundles alternate with small bundles (Lynch et al., 2006). In our study, vascular bundles are in two rows in A statistical comparison of anatomical features in some.

O. narbonense and O. montanum are in three rows in O. wiedemannii var wiedemannii, O.sigmoedeum, and O. lanceolatum. Lynch et al. (2006) reported that Hyacinthaceae has a wide range of variation in the crystal types. There are raphide, styloid and druse crystals in this family (Lynch et al., 2006). Raphide crystals are present in the stem cortex of O.sigmoedeum. The presence, morphology and distribution of crystals within a species are very important, because it is under genetic control (Franceschi and Nakata, 2005). Thus, the constancy of crystal type and distribution can be viewed as a taxonomic character for classification of species. Leaf anatomy of the taxa shows some differences. The mesophyll in O. montanum and O.sigmoedeum species is unifacial while it is equifacial in other taxa. The mesophyll in O. narbonense, O. wiedemannii var wiedemannii, O. lanceolatum. differentiates as palisade and spongy parenchyma. The palisade parenchyma is present in both the adaxial and abaxial side. Also, the mesophyll in O. lanceolatum contains larger aerenchyma between vascular bundles in spongy parenchyma.

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• 1
  Recebido para publicação em 1.9.2015 e aprovado em 5.2.2016.

Publication Dates

• Publication in this collection
  Jul-Sep 2016

History

• Received
  01 Sept 2015
• Accepted
  05 Feb 2016