. 2020 Dec 21;11:569905. doi: 10.3389/fpls.2020.569905

TABLE 2.

AMOVA and gene diversity for five germplasm sub-sets defined according to passport data: (A) GDP without the wild accessions, with grouping based on historical selection steps: T. dicoccum accessions, T. durum germplasm sub-sets landraces, T. durum germplasm sub-sets cultivars; (B) all T. durum germplasm sub-sets; groups are EPO, T. durum germplasm sub-sets landraces, modern lines; (C) all landraces grouped according to country of origin; (D) all T. durum germplasm sub-sets modern lines, classified according to decade of release; (E) all T. durum germplasm sub-sets modern lines, classified based on breeding program.

(A)

Source of variation	d.f.	Sum of squares	Variance components	Percentage of variation
Among populations	2	222,822.13	443.9	22.98
Within populations	859	1,278,090.16	1,487.88	77.02
Total	861	1,500,912.3	1,931.79
F_st		0.23

T. durum groups	N° accessions	N° polymorphic loci over 10173	Nei’s gene diversity	Mean number of pairwise differences

LANDRACE	286	10,154	0.332	3,375.08
EMMER	103	9,901	0.317	3,220.49
MODERN	473	10,010	0.264	2,681.76
Mean value			0.304	3,092.45
Lsd (p = 0.0005)			0.002	17.7

(B)

Source of variation	d.f.	Sum of squares	Variance components	Percentage of variation

Among populations	2	103,704.61	207.33	13.06
Within populations	852	1,175,524.24	1,379.72	86.94
Total	854	1,279,228.85	1,587.05
F_st		0.13
PIC		0.273	range (0.09–0.375)

T. durum groups	N° accessions	N° polymorphic loci over 8802	Nei’s gene diversity	Mean number of pairwise differences

LANDRACE	286	8,796	0.358	3,151.85
MODERN	473	8,781	0.292	2,567.05
EPO	96	8,213	0.288	2,538.16
Mean value			0.313	2,752.35
Lsd (p = 0.0005)			0.002	17.6

(C)

Source of variation	d.f.	Sum of squares	Variance components	Percentage of variation

Among populations	13	62,147.3	169.12	10.1
Within populations	270	403,266.13	1,504.72	89.9
Total	281	465,413.43	1,673.84
F_st		0.101
PIC		0.282	range (0.09–0.375)

Landrace group	N° accessions	N° polymorphic loci over 9414	Nei’s gene diversity	Mean number of pairwise differences

Turkey-Transcaucasian	29	9,253	0.374	3,521.67
Central Asia	18	9,035	0.356	3,348.15
Arabian Peninsula	9	7,790	0.349	3,285.50
Iberian Peninsula	21	9,048	0.346	3,253.83
Central Europe	18	8,547	0.341	3,206.41
South Asia	6	6,640	0.329	3,094.53
Greece	16	8,539	0.327	3,082.52
Italy	34	8,656	0.303	2,874.58
Ethiopia	26	8,174	0.302	2,843.20
North Africa	47	9,059	0.301	2,839.57
Argentina	5	6,107	0.300	2,829.40
Levant	46	8,496	0.289	2,722.53
North America	5	5,340	0.280	2,640.00
Australia	2	3,136	0.333	3,136.00
Mean value			0.323	3,048.42
Lsd (p* = 0.05)			0.005	48.1
Lsd (p* = 0.001)			0.008	75.8

(D)

Source of variation	d.f.	Sum of squares	Variance components	Percentage of variation

Among populations	4	13,737.04	29.36	2.95
Within populations	444	429,609.05	967.59	97.05
Total	448	443,346.08	996.95
F_st		0.029

Breeding decade	N° lines	N° polymorphic loci over 5685	Nei’s gene diversity	Mean number of pairwise differences

70–80	19	5,334	0.357	2,027.88
81–90	62	5,668	0.364	2,069.90
91–00	93	5,679	0.348	1,979.88
01–10	132	5,681	0.337	1,914.88
11–18	143	5,675	0.326	1,855.32
Mean value			0.346	1,969.57
Lsd (p = 0.0005)			0.003	33.2

Breeding group	70–80	81–90	91–00	01–10	11–18	Total

Australia	0	1	2	5	4	12
Central Asia	2	1	3	2	1	9
Central Europe	0	1	4	2	12	19
CIMMYT	3	2	5	6	29	45
Spain	3	4	10	6	1	24
Ethiopia	0	0	1	1	3	5
France	0	7	12	13	7	39
ICARDA	0	8	12	45	40	105
Italy	9	12	22	23	14	80
North America	2	8	13	5	5	33
South America	0	7	1	7	10	25
South Mediterranean	0	11	8	17	17	53
Total	19	62	93	132	143

(E)

Source of variation	d.f.	Sum of squares	Variance components	Percentage of variation

Among populations	11	60,189.98	121.56	11.67
Within populations	460	423,162.29	919.92	88.33
Total	471	483,352.27	1,041.48
F_st		0.117
PIC		0.278	range (0.09–0.375)

Breeding group	N° lines	N° polymorphic loci over 5918	Nei’s gene diversity	Mean number of pairwise differences

Italy	80	5,885	0.343	2,031.16
Central Asia	14	5,463	0.339	2,006.78
France	39	5,768	0.339	2,006.03
South America	25	5,535	0.335	1,984.11
Spain	27	5,591	0.332	1,963.08
Central Europe	25	5,466	0.321	1,902.33
South Mediterranean	53	5,776	0.312	1,848.12
Ethiopia	8	4,253	0.297	1,755.71
North America	33	5,316	0.296	1,749.61
ICARDA	110	5,813	0.294	1,741.78
CIMMYT	46	5,046	0.256	1,513.59
Australia	12	4,208	0.255	1,506.68
Mean value			0.310	1,834.08
Lsd (p = 0.05)			0.005	29.7
Lsd (p = 0.001)			0.008	46.9

Geographic area of origin has been assigned to GDP landraces based on country where they have been sampled, as follows: North America: Canada + United States; Arabian Peninsula: Oman, Yemen, and Saudi Arabia; Central Europe: Bulgaria, Serbia, Poland, Ukraine, Hungary, Romania, United Kingdom, Germany, Sweden, Bosnia, and Herzegovina; Iberian peninsula: Spain and Portugal; Levantine: Iran, Iraq, Jordan, Syria, and Israel; North Africa: Egypt, Tunisia, Algeria, Morocco, Libya, and Malt; Turkey-Transcaucasia: Turkey, Armenia, Azerbaijan, and Georgia; South Asia: Pakistan and India; Central Asia: Kazakhstan, Russia, and Afghanistan. GDP modern lines have been assigned to breeding program based on the country where lines have been developed, as follows: South Mediterranean: Egypt, Algeria, Tunisia, Syria, Lebanon, Jordan, and Morocco; North America: Canada + United States (including Desert durum); Central Europe: Austria, Serbia, Hungary, Ukraine, and Bulgaria; Central Asia: Kazakhstan and Uzbekistan. For each summary, the first table reports results of AMOVA, the second table contains computations about gene diversity within groups/populations. AMOVA was significant at p < 10^–6 upon 10,000 permutations. LSD for within group gene diversity was calculated at the indicated p-value considering n = the least number of group genotypes, except for the landrace group where n = 5 was chosen. For decade of release, a third table reports the composition of each decade group with respect to the breeding programs.