PLANT BREEDING ASSIGNMENT WORK

2. PLANT BREEDING ASSIGNMENT WORK COWPEA TOPIC:-

3. COWPEA

4. INTRODUCTION • Cowpeas are one of the most important food legume crops in the semiarid tropics covering Asia, Africa, southern Europe and Central and South America. • A drought-tolerant and warm-weather crop, cowpeas are well-adapted to the drier regions of the tropics, where other food legumes do not perform well. • It also has the useful ability to fix atmospheric nitrogen through its root nodules.

5. BIOLOGICAL INFORMATION • Vigna unguiculata or cowpea is a self pollinating species belonging to the Fabaceae family. • Its genome is diploid 2n=2x=22. ORIGIN OF COWPEA • Cowpea is a native of Africa, with West Africa (Nigeria) being a major centre of diversity. • India appears to be a secondary centre of diversity since significant genetic variability occurs on the subcontinent. • it is likely that the crop was first introduced to India during the Neolithic • period. South-eastern Africa is however reported as the centre of diversity of the wild • Vigna species .

6. BOTANY AND ECOLOGY • They are mainly grown in the warm climates since they require warmsoil temperatures for good establishment. • They are adapted to a wide variety of soils from heavy to light textured and from the humid tropics to the semi-arid tropics. • the duration from sowing to flowering may range from 38 to 141 days. • Most cowpeas are in general photoperiodsensitive.

7. GROWTH HABIT • Cowpea is a warm-season, annual, herbaceous legume. • Cowpea generally is strongly taprooted. Root depth has been measured at 95 in. 8 weeks after seeding. • Cowpea seed ranges in size from the very small wild types up to nearly 14 inch long and the number of seeds per pounds range from 1600 to 4300. • The trifoliolate leaves develop alternately. Leaves are smooth, dull to shiny, and rarely pubescent. Commonly, the terminal leaflet is longer and larger.

8. PRODUCTION IN WORLD • An estimated 14.5 million hectares of land is planted to cowpeaworldwide. • Global production of dried cowpeas in 2010 was 5.5 million metric tons; Africa was responsible for 94% of this. • Nigeria is the largest producer and consumer of cowpea, producing 2.2 million metric tons of dried grain in 2010. • The average yield worldwide is estimated at 450 kilograms per hectare, the lowest of the major tropical grain legume.

11. POLLINATION OF COWPEA • It is highly self pollinated because of  Cleistogamy, Close proximity of the anthers and stigma and Simultaneous maturity of anthers and stigma • Selfing  • Keeping the plants in insect proof cages will lead to selfing. • Crossing  • Select young buds, in an inflorescence and remove all immature buds. • Split open the keel petals and remove the stamens one by one holding the filaments. • Bring corolla back to position and cover the bud with a folded leaflet. Protection is given by keeping the plants in insect proof cages. • Pollination is done on the next day morning by exposing the stigma from the keel petal and brushing it with the pollen collected from the male parent.

12. EMASCULATION OF COWPEA • Removal of stamens or anthers or killing the pollen of a flower without the female reproductive organ is known as emasculation. • Flowers open only once between 7 and 9 a.m. On cloudy days the flowers may open even in the afternoon. • the emasculation needs to be carried out in mature flower buds in the preceding evening. • The flower buds likely to bloom the next day is selected for emasculation. • The bud is held between the thumb and fore-finger with the keel side uppermost. A needle is run along the ridge where the two edges of the standard unite.

13. HYBRIDISATION OF COWPEA Pure-line selection  • numerous superior appearing plants are selected from a genetically variable population; • progenies of the individual plant selections are grown and evaluated by simple observation, frequently over a period of several years; • when selection can no longer be made on the basis of observation alone, extensive trials are undertaken, involving careful measurements to determine whether the remaining selections are superior in yielding ability and other aspects of performance. • Any progeny superior to an existing variety is then released as a new “pure-line” variety. • They provided a rich source of superior pure-line varieties, some of which are still represented among commercial varieties. • A very large number of varieties that differ from the original strain in characteristics such as colour, lack of thorns or barbs, dwarfness, and disease resistance have originated in this fashion.

14. Pedigree breeding • starts with the crossing of two genotypes, each of which have one or more desirable characters lacked by the other. • If the two original parents do not provide all of the desired characters, a third parent can be included by crossing it to one of the hybrid progeny of the first generation (F1). • In the pedigree method superior types are selected in successive generations, and a record is maintained of parent–progeny relationships.

15. THANK YOU SUBMITTED TO- THE COURSE TEACHER GPB201 (2+1) DEPARTMENT OF GENETICS AND PLANT BREEDING SUBMITTED BY- KIRAN KUMAR.S.R. A2- BATCH. ID. NO.BA1TAC030 UAHS.SHIMOGA