Cucumber seed production
Download as PPTX, PDF1 like4,237 views
This document provides information on hybrid seed production techniques for cucurbits. It discusses the floral biology of cucurbits, which are mostly monoecious with male and female flowers on the same plant. It describes the process of hybrid seed production, which involves bagging male and female flowers separately, rubbing pollen from the male parent onto the stigma of the female parent, and rebagging to avoid contamination. It also discusses other techniques like using gynoecious lines in cucumber and chemical induction of sex forms. Key steps in hybrid seed production and processing like field inspection, rouging, harvesting, and seed extraction methods are outlined.
Cucumber seed production
- 1. HYBRID SEED PRODUCTION TECHNIQUES IN CUCURBITS
- 2. Most of the cucurbits are monoecious in character and a few are dioecious. Male & female flowers borne separately in the same plant. Female flowers have a knob like structure below the flower. Flowers open early in the morning except bottle gourd and ridge gourd wherein it opens in the evening. Most of the cucurbits are cross pollinated crops. Pollination is largely done by insects (Jarnail et al., 1972). Floral biologyFloral biology
- 3. Male and female should be bagged with butter paper or polythene bags (15x10 cm) one day before the opening of the flower. At the time of flower opening the bags are removed & the pollen from the parent are rubbed over the stigma of the female flowers of the same variety. Female flowers are again bagged to avoid contamination. Bags should be removed one week after pollination. Fruits are removed when they are fully matured. In bottle gourd, ridge gourd & sponge gourds dried fruits are kept for storage & the seeds are extracted from them at the time of planting.
- 4. Seeds of cucurbits are highly sensitive to soil moisture. Seeds can be pre – germinated before actual field sowing by water soaking for 4hr. Germinated seeds can be separated daily till 6 days. The seed germinating after 6 days are of poor vigour. Germinated seeds can be sown in the pits by making small holes and dropping the seeds in the holes.
- 5. Land should be free of volunteer plants. Generally the soil should be well drained and aerated. Land Requirements Isolation Foundation – 1000 m Certified – 500 m Pollination is largely done by insects. Isolation distance all around seed field is necessary to separate the crop from field of other varieties, fields of the same variety not conforming to varietal purity and from wild cucurbit species.
- 6. Season • June – July & February-March Seed rate • 2.5 kg / ha Spacing • Sow the seeds in the pit size of 45 x 45 x 45 cm at 2.5 x 2.0 m spacing Female flower increase • Spraying of ethrel 200-250 ppm at two leaf stage and after a week of 1st spray.
- 7. HYBRIDS DURATION YIELD/ ha SALIENT FEATURES AREA TNAU Ash gourd Hybrid CO 1 120-130 D 90 t/ha. Fruits are oblong and medium in size. Tamil Nadu BITTER GOURD IARI Pusa Hybrid-1 55-60days. first picking 200 q/ha. Fruits are medium long, medium thick, glossy- green, suitable for pickling and dehydration. Pusa Hybrid-2 55-60days. first picking 190-200 q/ha. Fruits are spindle shaped, glossy green skin colour without tubercles Karnataka, Tamil Nadu and Kerala
- 8. BOTTLE GOURD Pusa Hybrid 3 IARI - 425 q/ha Fruits are green, slightly club shaped without neck, suitable for easy packing and long distance transportation, All over India TNAU Bottle gourd Hybrid CO 1 - 80 t/ha. Fruits are cylindrical, without crook neck, medium sized Tamil Nadu Hybrid -Kashi Bahar IIVR - 500-550 q/ha. This is a long fruited hybrid with green vine and vigorous growth, fruit straight, light green, U.P., Punjab, Bihar and Jharkhand
- 9. Family – Cucurbitaceae Origin – South Asia (India) Chromosome no. 2n =24 Introduction ✓ Summer vegetable crops ✓ Bitter taste of the fruit – due to tetracyclic terpenes in seeds . ✓ Oil from its seed is good for the brain.
- 10. Climate Warm season crop, it does not withstand even light frost. Seed does not germinate – below 11°C Grows best at temperatures between – 18 to 24°C. Female flowers are produced during the short days with cool temperatures and low light. Soil Sandy to heavy clay is the best suited. pH – 5.5 and 6.7. The soil should be well drained.
- 11. The dehiscence occurs when temperature ranges from 20.5 to 21.50c between 2.30 to 3.45 A. M. and it completes before 5 A.M. The stigma becomes receptive 12 hours before and remains so 24 hours after opening of flowers at moderate temperature.
- 12. Hills are prepared at proper spacing by adding well- rotten organic manure. North India - kharif - June to July; summer - January to Feb. South India - October to November. Seed rate - 1.5kg for male parent and 3.5kg for female parent for a hectare.
- 13. • Inflorescence – Cymose. • Monoecious. • Flowers are unisexual and actinomorphic. • Stigma receptivity – maximum 2 hrs. • Fruit – Pepo. • Exalbuminous. • Male flowers have 3 stamens with free filaments and anthers. • Female flowers have 3 united inferior carpels, with a style and 3 thick stigmas. Inflorescence – Cymose. Monoecious. Flowers are unisexual and actinomorphic. Stigma receptivity – maximum 2 hrs. • • • • • • • • Fruit – Pepo. Exalbuminous. Male flowers have 3 stamens with free filaments and anthers. Female flowers have 3 united inferior carpels, with a style and 3 thick stigmas.
- 14. Female flower : • • • • • • Produced during the short days with cool temperatures and low light Usually solitary. The corolla is yellow, about an inch long, bell shaped, 5 petals, wrinkly and hairy It is having 3 united inferior carpals, with a style and 3 thick stigmas Male flower : These are produced in the axil of the leaf These are having 3 stamens with free filaments and anthers
- 15. Hybrids Yield Swarna sheetal 20-30 t/ha Pusa sanyog 15 t / ha NS 45 200 g weight. NS 46 150 g weight
- 16. Lack of standardized techniques for commercial seed production of hybrids is one of the major reasons that restrict the popularization of hybrid seeds. Production of hybrid seed of cucurbits needs some special considerations. Depending on the floral biology, one of the following methods can be followed for large scale hybrid seed production. a. Picking of male flowers & artificial pollination b. Picking of male flowers & insect pollination c. Use of gynomonoecious lines (cucumber) d. Use of male sterile lines (muskmelon, squash, pumpkin)
- 17. 1. Picking of male flowers and artificial pollination In monoecious plants, emasculation is not required. Female and pollen parent lines are planted alternately in an isolated field. Male flowers from the female parent are pinched before they open. Pistillate flowers of the female parent are artificially pollinated with the pollen of the male parent using cotton puffs by manual labour. 2. Picking of male flowers and insect pollination Female and pollen parent lines are planted alternatively in an isolated field. Male flowers from the female parent are pinched before they open. Female flowers are left on the seed parent and allowed to be pollinated by insects from the pollen parent.
- 18. 3. Use of gynoecious lines (Cucumber)
- 19. The gynoecious sex form have been commercially exploited in hybrid seed production of cucumber (Pusa Sanyog) at IARI R.S. Katrain. Performance is unstable under high temperature and longer photo period. It is not suitable for tropical regions. In IARI, tropical suited gynoecious lines are developed.
- 20. Maintenance of gynoecious lines In gynoecious lines, only pistillate flowers are produced and so it requires staminate flowers for self pollination. For production of staminate flowers, GA3 100 ppm is sprayed thrice at 15 days interval from 2ndleaf stage or single foliar spray of silver nitrate 600 ppm is done before 1stflower open. It induces staminate flowers for fertilization of pistillate flowers. ➢ At physiological maturity / ripening, fruits are harvested and seeds are extracted. Such seed when sown in next generation will produce only pistillate flower.
- 21. by theThe hybrid seed can also be produce in cucurbits application of chemicals for attaining the sex of cucurbits. Specific chemicals are known to induce femaleness and maleness as desired. The spraying of ethrel (2-choloro-ethyl-phosphonic acid) 200-300 ppm at two and four true leaf stage and another at flowering is useful for inducing the pistilate flower successively in first few nodes on the female in bottlegourd, pumpkin and squash for F1 seed production, Verma et al., 1985.
- 22. Field inspection and rouging Minimum of 3 field inspections - before flowering - during flowering and at immature fruit stage - during mature fruit stage In case of hybrids, at least 4 field inspections are necessary Isolation, planting ratio, off-types, nicking of male buds in the seed parent block, ascertaining accuracy in emasculation or to check pollen shedding cymes in male sterile lines and to verify true fruit characteristics. Maximum percentage of off types permitted foundation seed - 0.10% certified seeds - 0.20%
- 23. HARVESTING Harvesting of the fruits at appropriate maturity stage should be done. In some cases one picking for consumption/commercial as fresh vegetable does not affect the ultimate seed yield but adds to the farmers income. Fruits of bottle gourd are ready for seed beyond the edible fruit maturity. Skin of bottle gourd becomes hard and colour changes to light brown or yellow at seed maturity. Colour of bitter gourd and snake gourd changes yellow / orange / red from green at maturity. In ash gourd white colour ashy coating and metallic sound indicates the maturity. In ribbed gourd, complete drying of fruits and turning of colour from green to brown.
- 24. Seed extraction Seed separated from the pulp by •Fermentation and repeated washings OR •Mechanical OR •Chemical methods OR •Dry extraction method
- 25. Fermentation method Pulp is allowed to ferment in wooden or non-metallic barrels for about 30 hrs with occasional stirring to prevent growth of moulds of the seed surface. Separated clean seeds sink to the bottom and can be collected, washed and dried. Then the seeds are separated by rubbing with hands with excess quantity of water.
- 26. Mechanical method In the mechanical method, fruits are cut and macerated mechanically and the pulp is squeezed forcibly for separating the seed. Chemical method In the chemical method, seed is extracted with the use of an acid or alkali. Eg. In ash gourd the fruits are cut into 4 pieces and the central portion is scooped out. Then the seeds are extracted using HCL. 1N Hydrochloric acid (50-60 ml) is thoroughly mixed with 10kg pulp and allowed to stand for about 30 min. Seed is then washed thoroughly to remove the residues of acid / alkali and dried to safe MC.
- 27. Dry Extraction • Dry extraction processes are usually adopted for ribbed gourd & bottle gourd – In ribbed gourd the dried pods are cut opened at the distal end and seeds are collected and cleaned – In bottle gourd the fruits are cut opened at the proximal end and seeds are collected • Seed is scooped out of the fruit and sun dried. The clean seed is then removed by rubbing over a sieve and winnowing or blowing to separate the inert matter. • Seeds may be washed once, if necessary and then re-dried to safe seed MC. • In this method machines, like Axial Flow Vegetable Seed Extractor
- 28. Seed recovery Bitter gourd - 30% Snakegourd - 15-16% Ribbed gourd - 13-14% Ash gourd - 1.0-1.3% Drying Drying is done to reduce the MC in the seed to safe limit because SMC affects the germination and storability. Grading or size separation Various equipments such as air-screen cleaners, gravity and indented cylinder separators, etc. are available in the market which can be taken up as per the requirements. Farmer can use even hand sieves for taking up the enterprise on a very small scale. Mostly 16/64” round perforated sieves are used for grading
- 29. Crops Seed yield (kg/ha) Test Weight (g) 1000 seedOpen pollinated Hybrid Ash gourd 250-400 200-350 70 Bottle gourd 300-500 240-500 150 Bitter gourd 100-300 80-240 60 Ridge gourd 300-400 240-320 90 Sponge gourd 300-400 240-320 90 Muskmelon 200-300 240-320 25 Watermelon 250-400 160-240 70 Round melon 300-400 175-320 80 Long melon 200-300 240-320 30 Cucumber 300-400 160-240 23 Pumpkin 300-400 240-320 170 Summer squash 300-400 240-300 150 Winter squash 300-400 250-300 125 Snake gourd 300-400 250-300 150