Floral biology and breeding techniques

1. PUMKIN

2. INTRODUCTION
 Common name: Pumpkin
 Scientific name :Cucurbita
Moschata
 Chromosome number:
2n=2x=40
 Origin :America
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3. Cultivation details
Requires a rich, well-drained moisture
retentive soil and a very warm, sunny and
sheltered position.
a pH of 5.5 to 5.9, but tolerates up to 6.8
Plants are tolerant of light shade
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4. BOTANY
 It is allopolyploid with 2n=40
 Stem is angular, five ridged without hairs,
trailing and branched. Trailing vine
strikes roots at nods.
 Leaves: deeply or shallowly lobed not
pinnatifid
 Fruits have diuretic and vermetic action,
 Seeds are non bitter, tasty and nutritious.4

5. FLOWER STRUCTURE
 Flowers are large and yellow
colored with showy companulate
corolla.
 Ovary is inferior and 3 carpellary
 Corolla: companulate,
gamopetalous, lobed
 Plants are monoecious, highly cross
pollinated, entamophilous, 3
anthers. 5

6. FLOWERING
 Cucurbita moschata, an obligate short-day flowering
wild squash.
 Flowering start 30-45 days after sowing and it follows a
definite sequence of male and female flowers follows
up to fruit set.
 The 1st 4-6 flowering nodes bear male flowers and later
female flowers.
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10. BREEDING METHODS
 It is highly cross pollinated due to monoecious nature
and entamophily.
 The main objectives of breeding are: High fruit yield,
early fruiting, first pistillate flower at early node no.,
high femele to male ratio, yellow or mottled skin of
fruits, non-ridged fruit surface.
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11. HYBRID BREEDING
 Pollination takes place early in the morning between 6-
8 a.m.
 The common methods of commercial f1 hybrid seed
production are :
 Manual pollination/use of insects and use of chemicals
products.
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12. 1. MANUAL / USE OF INSECTS
 Male and female parents are planted in ratio 10:1
respectively. Since cucurbita flowers are large, male
buds are detected and removed several days before
anthesis from female rows.
 The female flowers are hand pollinated by male parents
or left for pollination by insects nature.
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13. 2. USE OF CHEMICAL
PRODUCT
 Production of male flowers on monoecious plants can be
temporarily suppressed,
 For 2-3 weeks by a repeated sprays of ethephon at
250ppm on young plants at 1st true leaf stage.
 SHANON and ROBINSON used 2 applications of ethephon
at 600ppm at the 2 and 4 leaf stage and reported
complete male suppression during the fruiting stage.
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