Potato breeding

potato-solanum tubersosum
Family-solanceae
pollination -self pollination,vegaetatively propagated
Floral biology
potato modified stem

1. king of vegetables “potato”

2. INTRODUCTION Potato is the fourth major food crop after rice, wheat and maize in the world. Potato is a temperate crop grown under subtropical conditions in India. The potato is a crop which has always been the ‘poor man’s friend . Potatoes are an economical food; they provide a source of low cost energy to the human diet. Potatoes are a rich source of starch, vitamins especially C and B1 and minerals. They contain 20.6 per cent carbohydrates, 2.1 per cent protein, 0.3 per cent fat, 1.1 per cent crude fibre and 0.9 per cent ash. They also contain a good amount of essential amino acids like leucine, tryptophan and isoleucine etc

3. Potatoes are used for several industrial purposes such as for the production of starch and alcohol. Potato starch (farina) is used in laundries and for sizing yarn in textile mills. Potatoes are also used for the production of dextrin and glucose. As a food product itself, potatoes are converted into dried products such as ‘potato chips’, ‘sliced’ or ‘shredded potatoes’

4. The potato is a native of tropical south American region. It is believed that the cultivated potato originated from its wild ancestors near the lake Tritica basin in Peru Bolivian region in high mountains . Potato was introduced into India by Portugese in 17 th century It was originated from wild diploid species Solanum leptophytes and the first domesticated species was Solanum stenotum . ORIGIN AND DISTRIBUTION

5. China ranks first in area and production followed by Russian Federation, Ukraine, Poland and India . Uttar Pradesh and West Bengal are the major potato producer states in the countries India occupies → 2nd Position in area & production in the world The China → World leader in Potato production (45.7 MT/ha) U.P is the major producer of potato (24 MT/ha) The highest productivity is in west bengal (24 mt/ha) followed by Gujarat (22.6 MT/ha)

6. Botanical Name : Solanum tuberosum Family : Solanaceae(nightshades) Chromosome Number : 2n= 4x=48 Pollination : self pollination(bisexual flower) cross pollination(Bumble bees) Local name : Dampala ( telugu ) Allu ( oida ) Propagation type : True potato seed, vegetatively propagated.

7. Potato has basic chromosome number 12. Form diploid to hexaploid species are available. About 75% species are diploid while about 15% species are tetraploids Triploids and pentaploids are highly sterile and maintained by vegetative propagation. S.stenotomum , S.phureja & S.ajanhuiri –diploids(2n=24) S.chaucha & S.Juzepezukii - triploid, more or less sterile(2n=36) PLOIDY STATUS

8. The cultivated tetraploid(2n=48) species S.tuberosum spp tuberosum & S.tuberosum spp andigena are fertile . S.curtilobum (2n=60) is pentaploid. Solanum tuberosum ssp. tuberosum produces tubers under long days or short days in the tropics or lower altitudes of 500-2000 m above Solanum tuberosurm ssp. andigena produces tubers at high altitude only (above 2000 m ) under short day conditions Nearly all the diploid species are self-incompatible while all the tetraploids & hexaploids are self compatible .

9. Wild species Solanum leptophytes Solanum bolivense Solanum demissum progenitors Solanum sparsipilum Solanum acaule Solanum megistacrolobum

10. CULTIVATED SPECIES

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

12. Habit - Potato is a much branched ,erect spreading spreading herb,growing 0.5 - 1.5m height Leaves - compound,pinnate ,10-20 cm long alternatively arranged Inflorescence- Monochasial cyme Flower - vary in colour from white,creamy,pink,purple Flowers are hermaphrodite(bisexual) Flowers are actinomorphic and hypogynous Mature fruit - Berry FLORAL BIOLOGY

13. POTATO FLOWER CALYX- 5 lobed,gamosepalous i.e five sepals that are partly joined at their base forming a bell shaped structure below the corolla. The calyx colour may be green or partially or totally pigmented. COROLLA - gamopetalous ,5 lobed STAMENS -5, alternate,with corolla lobes. Anthers are erect longer than the filaments with apical dehiscence .The anthers form a coneshaped structure through lateral joinings , to conceal the ovary OVARY - Superior, bicarpellary PLACENTATION - axial A photoperiod of 14-18 hours and night temperature of 15 to 20°C favour flower production

14. FLOWER BIOLOGY Anthesis time and closing of flowers varies with varieties and species Cool wet weather makes flowering more, while hot weather depresses flowering Pollen production is abundant from early morning to 10am Bombus impatiens is very effective in pollinating potatoes in the field Stigma receptivity and anther dehiscence are also at the same time Emasculation is usually done in Evening Diploid species have abundant pollen

15. EMASCULATION AND POLLINATION

16. Buzz pollination or sonication It a technique used by some bees, such as solitary bees ( Andrena carantonica ) to release pollen which is more or less firmly held by the anthers The anthers of buzz-pollinated plant species are typically tubular, with an opening at only one end, and the pollen inside is smooth-grained and firmly attached. With self-fertile plants such as potatoes wind may be sufficient to shake loose the pollen through pores in the anther and accomplish pollination Visits by bees may also shake loose some pollen, but more efficient pollination of those plants is accomplished by a few insect species who specialize in sonication or buzz pollination. In order to release the pollen, solitary bees are able to grab onto the flower and move their flight muscles rapidly, causing the flower and anthers to vibrate, dislodging pollen. Pollination involving vibrations is called buzz pollination . About 9% of the flowers of the world are primarily pollinated using buzz pollination.

17. Breeding Objective High tuber yield Earliness Photoperiod insensitivity Responsiveness to fertilizer Better keeping quality (resistance/tolerance against shrinkage,rottage etc) Better quality tubers Resistance to i . Late blight ii. Early blight iii.Charcoal rot iv.Common scab v. Bacterial wilt

18. POTATO TUBER PROPAGATION

19. TRUE POTATO SEED (TPS)TRUE POTATO SEED (TPS) Non-availability of quality seed tubers, high seed cost, virus infiltration in seed tubers causing degeneration of seed stocks and problems of long distance transport of seed from seed-producing areas have led to the development of true potato seed (TPS) technology of crop production. It can be easily stored over long periods of time. About 100-120 g TPS is enough to raise a seedling crop for one hectare or if the commercial crop is to be produced using seedling tubers, the produce of 40-45 g TPS is enough to plant one hectare crop next year. They also provide better disease resistance because of high heterogeneity in the population.