Potato is an important food crop that originated in South America. There are over 2000 species in the genus Solanum, with approximately 200 being tuber-bearing species like the cultivated potato (Solanum tuberosum). Wild potato species are a valuable genetic resource for breeding resistance to diseases and pests into cultivated varieties. Important wild species used in potato breeding include S. demissum, S. bulbocastanum, and S. stenotomum. Major international gene banks like the CIP in Peru conserve potato germplasm and provide access for breeding programs worldwide.

1. Genetic resources of potato
Ningappa kirasur
2014-12-129
Dept. of Olericulture
COH, Vellanikkara
1

2. Potato
o Solanum tuberosum
o Solanaceae
o 2n=48
o South America
o Fourth important food crop after rice, wheat and
maize
o Introduced to India in 17th century by Portuguese
2

3. Biosystematics
o Genus Solanum - consists of >2000 species
o More than 200 species were tuber bearing species
including 20 cultivated species
o The tuber bearing species are grouped under the section -
petota, sub section potatoe with 19 series.
o Among cultivated species , two important auto tetraploids
o S. tuberosum ssp tuberosum and S. tuberosum ssp
andigena
3

4. Contd…
o Two diploid species are S. phureja and S. stenotomum
o Other wild species of the series tuberosa are,
o S. sparsipilum, S. leptophys, S. berthaultii, and S.
spegazzinii, S. vernei
o Cultivated potato is crossable with other cultivated
species and wild diploid species
4

5. Contd…
5

6. Contd…
o Wild species have been found useful for transgression of
genes for resistance to diseases and insect pests
o The cultivated species S. tuberosum ssp tuberosum -
widely spread in Europe, USA, Canada and Asia
o While S. tuberosum ssp andigena - is grown only in the
andeas of South America
6

7. Origin and domestication
o Potato is originated in the Andean region of Peru and
Bolivia in south America
o It was domesticated in 10,000 – 7000 years ago
o First domesticated species was Solanum stenotomum,
which originated from the wild species S. leptophyes
o The other progenitors of present day cultivated potato,
with three wild species S. sparsipilum, S. acaule and S.
megistacrolobum
7

8. Contd…
8 Origin and domestication

9. Cytology
o Basic chromosome no. x=12
o Diploid 2n=2x=24
o Triploid 2n=3x=36
o Tetraploid 2n=4x=48
o Pentaploid 2n=5x=60
o Hexaploid 2n=6x=72
9

10. 1. Solanum stenotomum
2. Solanum phureja
3. Solanum goniocalyx
4. Solanum ajanhuiri
Diploid species (2n=2x=24)
10

11. Triploid species (2n=3x=36)
1. Solanum chauch
2. Solanum juzepczukii
Pentaploid species (2n=5x=60)
1. Solanum curtilobum
Contd…
11

12. Ploidy levels in potato
Ploidy level Numbers Percentage
2x 129 73
3x 7 4
4x 27 15
5x 3 2
6x 10 6
Total 176 100
12

13. Variability of tuber size in potato
13

14. 14

15. Wild species
1. Solanum leptophyes
2. Solanum sparsipilum
3. Solanum acaule
4. Solanum megistacrolobum
5. Solanum bolivense
6. Solanum demissum
7. Solanum microdontum
15

16. Solanum tuberosum var. tuberosum
Solanum vernei var. vernei
16

17. Solanum laxum
Solanum hjertingii17

18. Solanum microdontum
18

19. Solanum demissum
19

20. Solanum tuberosum var andigena
20

21. Solanum dulcamara
21

22. Solanum acaule
22

23. Solanum donianum
Solanum ensifolium
23

24. Solanum species Traits of interest
S. andigena Late blight, immune to virus x
and y
S. bulbocastanum Late blight resistance
S. jamessi Fusarium wilt resistance
S. pinnatisectum Late blight resistance
S. stenotomum Frost resistance
S. stoloniferum Immune to PVA and PVY ,
resistance to late blight
S. multidissectum Nematodes resistance
Species used for introgression of genes in to potato
24

25. Source of resistance in wild species
o Solanum demissum - late blight, leaf roll virus
o Solanum acaule - PVX, PLRV, spindle tuber viroid
o Solanum chacoensis - PVA, PVY, late blight, tuber moth
o Solanum spegazzinii - Fusarium, wart, cyst nematode
o Solanum stoloniferum - PVA, PVY
o Solanum vernei - Cyst nematode
25

26. Potato germplasm conservation institutes
o CIP- International potato center - Peru
o CPRI- Central potato research institute- Shimla
o Gene bank holds 80% of the worlds native potato and
sweet potato germplasm
o Also maintains more than 1,500 accessions of native
Andean root and tuber crops (ARTCs )
26

27. Contd....
o In vitro germplasm is available for distribution
o Used in breeding programs over 100 countries
o CIP’s in vitro gene bank is the first to obtain International
Standards Organization (ISO) 17025 accreditation for safe
and secure germplasm movement
27

28. Contd…
28

29. 29