HYBRID SEED PRODUCTION IN TOMATO
Dec 22, 2015
HYBRID SEED PRODUCTION IN TOMATO
CLIMATE
• Grows best in the warm and dry season• Day temperature 21-25°C• Night temperature of 15-20°C• Temperature ˃ 30°C and ˂ 10°C is not
favorable• Relative humidity 60-70℅
Planting and Spacing
• Seed of male parent should be sown 2-3 weeks earlier to ensure adequate supply of pollen
• Planting ratio 5:1• Spacing – Female line = 80 x 60 cm– Male line = 60 x 40 cm
ISOLATION
• Isolation of male and female parental lines is not necessary
• Seed production field of two hybrids should be isolated by 25 m
Hybridization technique
• Emasculation– 55-65 Days before pollination
Male sterility
• First time used by Prof. C.M Rick 1945• Types– Sporogenous male-sterile mutants– Functional male-sterile mutants– Photoperiod sensitive male-sterile mutant– Temperature dependent male-sterile mutant
Sporogenous male-sterile mutants
• Not determined– Point of arrest in pollen development has not yet
been determined• Premeiotic– Pollen mother cell collapse or abort prior to
meiotic phase• Meiotic – Abnormalities in tapetal cell
Continued…..
• Tetrad– Meiosis completed before pollen abortion. Tapetal
cell fail to expand to normal volume producing small locules at anthesis.
• Microspore – Pollen abortion after microspore formation– Microspores do not enlarge
Functional male-sterile mutants
• Cleistogamous mutant– Petals fails to open
• Dialytic mutant– Growth of epidermal hairs on the anther surface is
prevented.• Exserted stigma mutant– Due to excessive length of style.
Continued……
• Positional sterile mutants– Overlapping or curling of petals– Holds the anthers in close contact with pistil
• Positional sterile-2 mutants– Characterized by the presence of fertile pollen and
indehiscent anthers
Photoperiod sensitive male-sterile mutant
• 100% male sterility in long days (LD 12 h day length)
• Male fertility in short days (SD 8h)
Temperature dependent male-sterile mutant
• Better fruit and seed set at 12°C than 24°C.
Pollination
• 8:00 to 11:00 am• 2 to 3 days after emasculation
Fruit production
• No. of fruits to be kept depend on fruit size of female parent– 30 fruits for large fruited (80 g)– 40 fruits for medium fruited (70-80 g)– 50 or more fruits for small fruited (60 g or below)
Harvesting
• Ripened about 50-60 DAP• Harvested at red ripe stage
Hybrid seed yield
• One kg fruit yields 2.5 to 4 g hybrid seed• Determinate growth 40-50 kg seeds/ha• Indeterminate 70-80 kg/ha