Seed production of Tomato
Floral biology
Botanical name-Lycopersicum esculentus
Family- Solanaceae
Chromosome No- 24
Origin-Peru(Mexico)
Family- Solanaceae
Chromosome No- 24
Origin-Peru(Mexico)
Inflorescence:
Extra-axillary cyme with dichotomous or polychotomous branching.
The
Flower:
Ebracteate,bright yellow, chasmogamous, pentamerous, actinomorphic,
hypogynous, hermaphrodite, with pistil enveloped by a solid tube formed by the
stamens.
Calyx:
5 sepals, united, often persistent, possesses trichomes.
Corolla:
Bright yellow, 5 petals, gamopetalous.
Androecium:
5 stamens, epipetalous, small filaments, large anthers, stamens form a
solid cone enclosing the pistils. Anthers dehiscence is introsely longitudinal.
Gynoecium:
Ovary- superior bicarpellary & syncarpous
Style- single
Stigma- bilobed
Anthesis:
Starts in morning around 6 am and continues till 11 am. Maximum flower opening- 7 to 9 am. Stigma receptivity- 16 to 18 hrs before anthesis to 5 to 6 days after anthesis. Pollen viability- 2 to 5 days (18-25*C) & upto 6 months in a dessicator (5*C).
Tomato is one of the most important vegetable crops grown extensively in the tropical and subtropical belts of the world. It is grown mainly fresh market and to a little extent for processing. Increased attention is now being bestowed to breeding and production of tomato.
Ovary- superior bicarpellary & syncarpous
Style- single
Stigma- bilobed
Anthesis:
Starts in morning around 6 am and continues till 11 am. Maximum flower opening- 7 to 9 am. Stigma receptivity- 16 to 18 hrs before anthesis to 5 to 6 days after anthesis. Pollen viability- 2 to 5 days (18-25*C) & upto 6 months in a dessicator (5*C).
Tomato is one of the most important vegetable crops grown extensively in the tropical and subtropical belts of the world. It is grown mainly fresh market and to a little extent for processing. Increased attention is now being bestowed to breeding and production of tomato.
Production of tomato can
further be increased if improved cultural practices are combined with good
quality seeds. The quality seed production techniques in tomato comprises of
the following steps.
Botany
Tomato is a typical day neutral plant. It requires temperature of 15-20° C for fruit setting.
Tomato is a typical day neutral plant. It requires temperature of 15-20° C for fruit setting.
Tomato is self pollinated crop. Self fertilization is
favoured by the position of receptive stigma within the cone anthers and the
normal pendant position of the flower.
Method of seed production: Seed to Seed.
Stages of seed production:
Breeder seed - Foundation Seed
I - Foundation Seed II - Certified Seed
Varieties :
Indeterminate varieties:
Pusa Ruby, Solan Gola, Yaswant (A-2), Sioux, Marglobe,
Naveen, Ptom-9301, Shalimar- 1,
Shalimar-2. Angurlata, Solan Bajr, Solan Sagun, Arka
Vikas. Arita Saurbh.
Determinate varieties:
Roma (EC-13513), Rupali, MTH-15, Ptom-18, VL-1, VL-2, HS
101, HS 102, HS 110, Pusa EarlyDwarf, Pusa Sheetal, Floradade, Arka Meghli,
Co.1, Co.2, Co.3 (Marutham), PKM.1, Py1,
Hybrids:
COTH-1, Pant Hybrid-2, Pant Hybrid-10, Kt-4. Pusa
Hybrid-l-4, Arka Shreshta, Arka Vardan,
Arka Abhijit, Navell 1 &2 (Sandoz), Rupali, Sonali,
MTH 6
Season : May - June and November - December
Land requirement:
Selection of suitable land for tomato seed production is
important where the previous crop should not be the same variety to avoid the
contamination due to the volunteer plants. The soil of selected fields should
have good texture,fertile and be well-drained. The pH of soil should be from 6
to 7.
Isolation requirement:
For Seed production of tomato, varieties require minimum
of 50 M for foundation seed and 25 M for certified seed. For hybrid seed
production, it requires minimum of 200 M for foundation (parental line
increase) and 100 M for certified hybrid seeds.
Seed rate:
For i) Varieties - 300- 400 g/ha ii) For F1 hybrid - Male
parent 25 g/ha; Female parent 100 g/ha.
Sowing of seed
nursery:
The
nursery grown in late October and transplanted in the first week of December
produces excellent seed crop. Seeds may be sown on raised nursery beds (15-20cm
high from ground) in rows 3-4 cm apart. Twenty five nursery beds of size 2-2.5
m long and 1 to 1.25 m wide will raise enough seedlings to transplant one hectare. Apply 2 kg of DAP 10days before
pulling out of seedling.
Transplanting:
Transplanting should be done with the seedlings are 20-25 days old, preferably at evening time.
Transplanting should be done with the seedlings are 20-25 days old, preferably at evening time.
Spacing:
Spacing is 60 x 45 cm (90 x 60 cm for female parent and
60 x 45 cm for male parent of hybrids).
Manuring:
After thorough preparation of a field to fine tilth,
apply 25 tons of FYM per ha. Apply 100 : 100: 100 Kg of NPK/ha.
Roguing:
The roguing should be done based on the plant characters
(determinate / indeterminate), leaf, branching and spreading characters and
also based on fruit size, shape and color. The plants affected by early blight,
leaf spot and mosaic (TMV) diseases should be removed from the seed production
field.
Planting ratio:
For hybrid seed production, the female and male parents
are normally planted in the ratio of 12:1 or 12:2.
Pest and disease management:
The major pests attacking tomato crop are leaf eating
caterpillars and fruit borers, which can be controlled by spraying. The major
diseases in tomato are early blight and mosaic virus. The early blight
rot can be controlled by spraying Benlate or Dithane M-45.
Harvesting seed extraction and processing:
The fruits are harvested after full maturity of the fruit
when turn in to red color fruits from first and last one or two harvests should
not be used for seed extraction.
Stages
of maturation: Mature green, Breaker, Turning, Pink, Red, Dark
red / over ripe.
The fruits from in between 6-7
harvest should be used for seed extraction. The seed viability is depends on
the method on which the seeds were extracted and hence, it is more important to
choose proper methods of seed extraction. Before seed extraction, the fruits
are to be graded for true to type and selection of medium to large size fruits
for getting higher recovery of quality seeds.
The
acid method of seed extraction is the best method for tomato seed extraction.
In this method, the fruits are to be crushed into pulp and taken in a plastic
containers (or) cement tank. And then add 30 ml of commercial Hydrochloric acid
per kg of pulp, stir well and allow it for ½ hour. In between this duration the
pulp may be stirred well for one or two times. This facilitates the separation
of seed and pulp. After ½ hour, the seeds will settle down at the bottom and
then the floating fraction is to be removed. The collected seeds should be
washed with water for three or four times.
Ø While following
acid method we must use only plastic or stainless steel containers or cement
tank.
Ø seeds and as
well damage to the containers due to chemical reaction with acid.
Ø For large scale
seed extraction we can use the tomato seed extractor developed by Tamil Nadu
Agricultural University.
Ø The seeds
extracted by this machine may again be treated with commercial Hydrochloric
acid @ 2-3 ml/kg seed with equal volume of water for 3-5 minutes with constant
stirring. And then seed should be washed with water with water for to four times.
Ø It is easy to
dry the seeds extracted by acid method and also remove the fungus growth over
the seed coat, thus seeds possess golden yellow colour and high vigour.
Ø The seed
extracted by fermentation method posses poor vigour and off colour due to
fungal activity. The fermentation process is an old established procedure which
effectively controls bacterial canker. It is best to allow the mass of fruit
pulp and juice to ferment without the addition of water.
In
alkali method equal volume of an alkali mixture (425 gm ordinary washing soda
added to 5 litre of boiling water) is added to pulp and mixed. When the alkali
mixture is cooled, allow it all to stand overnight in an earthen pot. Next day,
all the seed will settle down at the bottom of the container. Now decent-off
the clear liquid at the top and wash the seeds thoroughly.Ø
Comparison of
different seed extraction methods:
Fermentation
|
Acid
|
Alkali
|
|
Method
|
Mix fruit pulp
with water -
24 - 48 h
|
HCl @10ml /
Kg of pulp -
20-30 minutes
|
Washing soda @
900mg/4 l of
water- equal
volume –
overnight soak
|
Salient
features
|
Ø Low cost.
Ø Unskilled
labour.
Ø More Time
taken
Ø Low Seed
recovery
(0.5 to 0.6 %
Ø Dull seed
colour.
Ø Seed. borne.
Pathogens
|
Ø Cost is more.
Ø Skilled labour
Ø Lesser Time
Ø High seed
recovery
(0.8 to 1 %)
Ø Bright colour
market value
higher.
Ø Seed borne
pathogen –
removed
Ø Improper
washing
leads to
injury to
seeds
|
Ø Recovery 0.7
to 0.8
per cent
Ø Luster of the
seeds will
be lost.
Ø Improper
washing
leads to
injury to seeds
|
Fermentation method:
Washing:
After extraction
the seeds are washed with water to remove the pulp, etc. The water is added to
containers with the pulp and seed. It is stirred thoroughly and is drained out
along with pulp and other mucilaginous substance. The process is repeated until
the seeds are clean.
Drying and
grading:
Seeds are to be dried in the
shade. It should never be dried in hot sun. Under artificial condition the seed
should be first dried at low temperature and then the temperature should be
gradually increased to 40*C .The safe moisture content of the seed for grading
is 8 to 9 per cent. Seeds can be graded using 6/64‟‟ round perforated sieve.
Storage:
The seeds dried to safe moisture
content after treating either with captan or thiram @ 2 g/kg can be stored for
15 months in moisture vapour pervious containers, while it can be stored in|moisture
vapour proof containers for 30 months.
Hybrid seed
production:
In tomato the hybrid seed
production is normally done by 'Emasculation and Hand Pollination'. However use
of chemical hybridizing agents (MH-1000 ppm) or CMS lines are also practiced.
Emasculation and dusting:
Emasculation and dusting:
1. Emasculation is done before
the anthers are mature and the stigma has become receptive to minimize
accidental self pollination.
Selection
of flower
1. Thus emasculation is generally
done in the evening, between 4 PM and 6 PM one day before the anthers are
expected to dehisce or mature and the stigma is likely to become fully
receptive.
2. Emasculate the bud by hand
with the help of needle and forceps. Remove the calyx, corolla and staminal
column or anthers, leaving gynoecium i.e., stigma and style intact in
the flower.
1. Emasculated flowers should be
covered immediately with red coloured paper cover to protect against
contamination from foreign pollen and also for easy identification of emasculated
bud during dusting.
2.
Remove the red paper cover of the emasculated bud and dust the pollen gently
over the stigmatic surface using cotton or camel brush, etc.
Seed Yield: 100 -120 Kg/ha.
Seed
Certification
Number of
Inspections:
A minimum of three inspections
shall be made as follows:
1. The first inspection shall be
made before flowering on order to verify isolation, volunteer plants, and other
relevant factors,
2. The second inspection shall be
made during flowering to check isolation, offtypes and other relevant
factors.
3. The third inspection shall be
made at maturity and prior to harvesting to verify true nature of plant and
other relevant factors.
Specific
requirements:
Factors
|
Foundation
|
Certified
|
Off types –
variety
|
0.1%
|
0.2%
|
Hybrid
|
0.01%
|
0.05%
|
Plants
affected by seed borne diseases
|
0.1%
|
0.5%
|
Factors
|
Foundation
|
Certified
|
Pure seed
(mini)
|
98%
|
98%
|
Inert matter
(maxi)
|
2%
|
2%
|
Other crop
seeds (maxi) 5/kg
|
5/kg
|
10/kg
|
Weed seeds
(maxi)
|
None
|
None
|
Germination
(mini)
|
70%
|
70%
|
Moisture
(maxi)
|
8%
|
8%
|
For VP
container
|
6%
|
6%
|
Raghvendra Singh
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