Karyological study and meiotic analysis of four species of Aegilops (Poaceae) in Algeria

Figures & data

Figure 1. Location of sampled populations of four species of Aegilops in Algeria (g = A. geniculata, n = A. neglecta, v = A. ventricosa and t = A. triuncialis). Bioclimatic limits according to Stewart (1974).

Table 1. Climatic and floristic characteristics of sampling sites of natural populations of Aegilops in Algeria.

Stations	Populations	Floristic characteristics	Alt (m)	M (C°)	m (C°)	P (mm)	Q2	Bioclimate
Littoral
El-kala 1	g29	Edge of way, in a lawn of Poaceae	30	27	2.8	1715	243.07	Humid
El-kala 2	g30	At the top of a hill with herbaceous plants	10	27	2.8	1715	243.07	Humid
Seraidi	g24	Lawn of Poaceae adjoining an olive grove (Olea europea)	200	26.2	3.8	919	140.72	Sub-humid
Skikda	g23	Edge of way adjoining an olive grove and pistachio (Olea-lentisque)	200	34.33	4.9	704	85.02	Sub-humid
Ançor	g2	Border road, in a lawn of Poaceae	150	25.5	7	457	75.9	Semi-arid
Ain-tassa	v1	Herbaceous lawn	100	25	6.60	437	81.46	Sub-humid
Tellian atlas
Zitouna	g28	Border road adjoining a field of olive and pistachio (Olea-lentisque)	500	29	4.2	1773	245.21	Humid
Bougous	g27	Lawn grasses at the edge of a forest of cork oak (Quercus suber)	250	29.6	4.8	1740	240.65	Humid
El-afrine	g26	Lawn of Poaceae, under Eucalyptus camelodesis	300	29.5	4.7	1750	242.03	Humid
Souk-ahras	g25	Degraded maquis of Chêne cork (Quercus suber)	500	24	6.3	729	78.4	Sub-humid
Constantine	g22	Road border under the Eucalyptus camelodesis	600	32.8	2.8	515	58.88	Semi-arid
Mila	g21	In herbaceous field	450	30.7	2.5	603	73.34	Sub-humid
Sétif	g20	Road border, in herbaceous field	650	32.8	6	470	60.15	Semi-arid
Ourissia	g19	Lawn of Poaceae bordering a forest of Pinus alepensis	800	32	5.2	500	63.99	Semi-arid
Kherata	g18	Road border, in herbaceous field	600	32.3	4	1103	133.68	Sub-humid
Timzrite	g17	On the edge of a field of fig (Ficus sp.)	700	35.6	2.1	503	51.5	Semi-arid
Stita	n1-g16	Lawn of Poaceae adjoining an olive grove (Olea europea)	300	28.9	6.3	1290	195.78	Humid
Ouaguenoune	n2	Bordering a road bordering a field of wheat (Triticum durum)	150	31.4	6.8	952	132.73	Humid
Taboukert	g13-n3-t3	Herbaceous lawns in banks of oued Sebaou	100	32.02	7.22	986	135.27	Humid
Timzguida	g14-n4	Border road adjoining a field of olive and pistachio (Olea lentisque)	300	30.7	3.9	1035	132.46	Humid
Tizi-rached	g15-n5-t4	Lawn of Poaceae adjoining an olive grove (Olea europea)	400	30.0	4.7	1210	163.9	Humid
Iguenane	n6	Roadside bordering a drill of holm oak (Quercus ilex)	600	32.0	2.7	1149	134.5	Humid
Ait-meraou	g12-n7	Bordering a field of fig tree (Ficus sp.)	650	31.6	2.9	1037	123.9	Humid
Benyenni	g11-n8	Grass lawn at the edge of a cork oak forest (Quercus suber)	850	32.6	2.8	1080	124.3	Humid
Tikjda 1	g9	Herbaceous lawn on flushing rock	1200	30.2	2.1	1100	134.2	Humid
Tikjda 2	g10-v4	Edge of cedar formation (Cedrus atlentica)	1478	29	0.9	1190	145.3	Humid
Relizane	t2	Under a forest of Pinus alepensis	630	28.7	5.8	325	48.67	Semi-arid
Mascara	g4	Under forest of Pinus alepensis	735	28.2	5.5	370	55.90	Semi-arid
Tessala 1	v3	Degraded maquis of Chêne cork (Quercus suber) on flushing rock	850	32.5	2.9	678	80.02	Sub-humid
Tessala 2	g3-v2	Degraded maquis of holm oak (Quercus ilex) on flushing rock	950	32.01	2.1	700	80.27	Sub-humid
Mansourah	g1-t1	Forest of Pinus alepensis and Quercus ilex	700	39.9	0.6	435	37.96	Sub-humid
Hamdania	g5	Lawn of Poaceae on the edge of a river	450	31.6	3.3	755	91.50	Sub-humid
Benchicao	g6	Road border in a lawn of Poaceae	1200	35	1.3	625	63.7	Semi-arid
Médea	g7	In formation of Pinus alepensis	600	32.2	2.7	800	93.3	Sub-humid
Berrouaghia	g8	Border road adjoining a green oak forest (Quercus ilex)	850	34.2	6	593	72.12	Semi-arid
Steppe highlands
Mesrane	g31	In steppe with Salsola vermiculata	1050	28.4	5	309	45.29	Arid
Guelt-estel	g32	In steppe with Lygeum spartum	900	28.9	5.8	285	43.32	Arid
Saharan atlas
Senalba	g33	Forest of Pinus alepensis	1350	33	−1	402	43.08	Semi-arid
Col des caravanes	g34-v5	Clearing, with herbaceous lawn	1300	36	−1.5	352	34.99	Arid
Messaad	g35	Clearing, with herbaceous lawn	750	34.5	−2	342	36.09	Arid
Taadmit	v6	Clearing, with herbaceous lawn	850	36	−1.25	321	32.38	Arid

Alt – altitude; M – average of the maximum temperatures of the hottest month; m – average of the minimum temperatures of the coldest month; P – average annual rainfall; Q2 – Emberger’s coefficient; g – Aegilops geniculata; t – Aegilops triuncialis; v – Aegilops ventricosa; n – Aegilops neglecta.

Table 2. Number of individuals, mitotic cells, absolute frequencies (FA) and relative frequencies (FR) of the chromosome numbers found in the populations of Aegilops from Algeria.

Species	Individuals	Mitotic cells	2n	Absolute frequencies	Relative frequencies
Aegilops geniculata	240	258	27	12	5.00
			28	209	87.09
			29	19	7.91
Aegilops neglecta	80	112	39	2	1.78
			40	7	6.25
			41	11	9.82
			42	75	67.00
Aegilops triuncialis	30	45	28	45	100
Aegilops ventricosa	40	42	27	6	1.42
			28	36	98.58

The bold values correspond to the true chromosomal numbers.

Table 3. Chromosome number (2n), karyotypes formulas, intrachromosomal (A1, CVci), and interchromosomal (A2, CVcl) asymmetry indices and the means values of the total length of chromosomes (Χ ± ES) of four species of Aegilops from Algeria.

Species	Cytotype	Chromosome number (2n)	Karyotype formula	X ± Es	CVci	CVcl	A1	A2
A. geniculata	1	28	7 m+4sm+3st+0t	24.23 ± 1.85	23.05	9.03	0.39	0.09
	2	28	3 m+8sm+2sm-s+1st+0t	18.61 ± 2.15	13.42	12.68	0.22	0.12
	3	28	6 m+4sm+4st+0t	20.14 ± 2.65	26.58	14.75	0.35	0.14
	4	28	5 m+6sm+3st+0t	15.73 ± 1.25	29.19	8.85	0.32	0.08
A. triuncialis	1	28	7 m+4sm+3st+0t	14.59 ± 2.13	26,01	25,94	0,44	0,25
	2	28	9 m+2sm+1sm-s+2st+0t	11.25 ± 1.09	24,61	21,58	0,32	0,21
A.ventricosa	1	28	10 m+3sm+1st+0t	10.38 ± 0.93	15,79	13,08	0,28	0.13
	2	28	6 m+5sm+3st+0t	16.41 ± 1.26	26,11	17,91	0,42	0,17
A.neglecta	1	42	7 m+9sm+5st+0t	14.36 ± 1,03	24.72	16.51	0.45	0.16
	2	42	13 m+5sm+1sm-s+2st+0t	13,22 ± 0.90	22.03	12.16	0,42	0,12

Figure 2. Micrographies of tetraploid metaphase plates (2n = 4x = 28) of Aegilops geniculata. (a–c) Cytotype 1; (d–f) Cytotype 2; (g–i) Cytotype 3; (j–l) Cytotype 4. st: satellite. Scale bar = 15 μm.

Figure 3. Micrographies of tetraploid metaphase plates (2n = 4x = 28) of Aegilops triuncialis. (a–c) Cytotype 1; (d–f) Cytotype 2. st: satellite. Scale bar = 15 μm.

Figure 4. Micrographies of tetraploid metaphase plates (2n = 4x = 28) of Aegilops ventricosa. (a–c) Cytotype 1; (d–f) Cytotype 2. Scale bar = 15 μm.

Figure 5. Micrographies of hexaploid metaphase plates (2n = 6x = 42) of Aegilops neglecta. (a–c) Cytotype 1; (d–f) Cytotype 2. st: satellite. Scale bar = 15 μm.

Figure 6. Haploid ideograms in the studied taxa of genus Aegilops in Algeria.

Figure 7. Principal coordinate analysis (PCoA) for Aegilops accessions based on six quantitative karyological parameters.

A. geniculata

A. ventricosa

A. triuncialis

A. neglecta.

Table 4. Correlation table with Pearson coefficient, among karyological characters and environmental factors.

	2n
x	0.31	x
THL	0.01	0.00	THL
MCA	0.02	0.00	0.47	MCA
CVCL	0.05	0.00	−0.48	−0.15	CVCL
CVCI	0.05	0.00	0.07	0.65	0.10	CVCI
Alt	−0.08	0.00	−0.56	−0.16	−0.17	0.34	Alt
M	0.03	0.00	−0.05	−0.01	0.09	0.23	0.35	M
m	0.05	0.00	0.15	0.12	0.18	−0.17	−0.78	−0.47	m
P	0.02	0.00	0.22	0.37	−0.03	0.11	−0.15	−0.16	0.00	P
Q2	0.02	0.00	0.28	0.41	−0.02	0.05	−0.34	−0.33	0.18	0.96	Q2

Table 5. Number of mother pollen cells (MPC) and MI configurations frequencies of Aegilops geniculata and Aegilops neglecta.

Species	Mother pollen cells (MPC)	Chromosome associations (MI configuration)			Relativefrequencies (%)
		II.a	II.d	U
A. geniculata	63	10	4	0	54.31
	39	9	5	0	33.62
	14	8	6	0	12.06
A. neglecta	12	9	10	2	40
	10	9	12	0	33.33
	8	10	11	0	26.66

MI – metaphase I; II.a – ring bivalent; II.d – rod bivalent; U – univalent.

Figure 8. Micrographs of pollen meiosis of Aegilops geniculata (2n = 4x = 28): (a) pachytene; (b) diakinesis; (c, d) metaphase I (U: univalent chromosomes); (e, f) anaphase I (Pch: chromatin bridges and Cr: chromosome lagging); (g) dyad; (h) tetrad; (i) pollen grain with pore aperture. Scale bar = 15 μm.

Figure 9. Micrographs of pollen meiosis of Aegilops neglecta (2n = 6x = 42): (a) pachytene; (b) diakinesis; (c, d) metaphase I (U: univalent chromosomes); (e, f) anaphase I (Pch: chromatin bridges and Cr: chromosome lagging); (g) dyad; (h) tetrad; (i) pollen grain with furrow aperture. Scale bar = 15 μm.

Stewart P. 1974. Un nouveau climagramme pour l’Algérie et son application au barrage vert. Bull Soc Hist Nat Afrique du Nord. 65:239–248.

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