Table 2 Interspecific cross-compatibility indices among yam species (Dioscorea spp.)

From: Cross compatibility in intraspecific and interspecific hybridization in yam (Dioscorea spp.)

Species and crosses

Females

Males

Cross-combinations

Flowers pollinated

ACR (%)

SPE (%)

D. alata × D. bulbifera

9

1

9

5710

3.66 ± 12.40

0.51 ± 7.31

D. alata × D. bulbifera wild

4

4

7

484

2.04 ± 7.41

0.00 ± 0.00

D. alata × D. cayenensis

4

3

6

927

0.00 ± 0.00

0.00 ± 0.00

D. alata × D. dumetorum

4

6

7

337

0.00 ± 0.00

0.00 ± 0.00

D. alata × D. rotundata

8

23

28

2807

5.31 ± 17.18

3.12 ± 14.57

D. bulbifera wild × D. rotundata

2

4

5

520

1.21 ± 2.46

0.07 ± 0.22

D. bulbifera × D. alata

14

5

21

2795

0.44 ± 2.11

0.00 ± 0.00

D. bulbifera × D. rotundata

9

7

19

3773

1.16 ± 6.28

0.09 ± 0.64

D. dumetorum × D. alata

4

2

6

181

11.80 ± 16.57

0.00 ± 0.00

D. dumetorum × D. rotundata

3

1

3

299

10.59 ± 18.16

0.00 ± 0.00

D. hirtiflora × D. rotundata

1

3

3

466

27.33 ± 35.80

0.52 ± 2.18

D. praehensilis × D. alata

3

3

6

2146

3.66 ± 3.42

-

D. praehensilis × D. rotundata

3

6

8

2400

11.97 ± 12.13

5.30 ± 7.14

D. rotundata × D. alata

7

5

12

4626

0.44 ± 2.52

0.09 ± 0.78

D. rotundata × D. bulbifera

8

4

11

6770

0.59 ± 3.72

0.24 ± 1.65

D. rotundata × D. bulbifera wild

7

1

7

5769

1.60 ± 7.31

0.38 ± 2.90

D. rotundata × D. burkilliana

3

1

3

680

29.20 ± 24.59

9.67 ± 9.21

D. rotundata × D. cayenensis

21

11

58

26,813

6.46 ± 13.24

0.77 ± 3.92

D. rotundata × D. dumetorum

3

1

3

221

0.00 ± 0.00

0.00 ± 0.00

D. rotundata × D. hirtiflora

6

1

6

1278

0.67 ± 3.11

0.00 ± 0.00

D. rotundata × D. praehensilis

1

1

1

102

9.80 ± 13.00

-

Sum/mean (± SD)

118

91

229

69,104

6.09 ± 9.59

1.09 ± 2.66

  1. The first species in the pedigree served as the female parent in the interspecific cross while the second species provided the male parents, ACR = average cross-compatibility/crossability rate, SPE = seed production efficiency. Dioscorea bulbifera wild refers to individuals of the species from the forest/wild environments. SD = standard deviation. ACR and SPE are presented by means ± standard deviation.