floral biology of important cucurbits
TRANSCRIPT
WELCOME
FLORAL BIOLOGY OF
IMPORTANT
CUCURBITS
Submitted by - Avisha Ram Budhani
1st semester M.Sc. (Horticulture)
ASPEE College of Horticulture & Forestry
Navsari Agricultural University, Navsari
Submitted to – Dr. Sanjeev Kumar
Assistant Professor
Department of Vegetable Science
ASPEE College of Horticulture & Forestry
Navsari Agricultural University, Navsari
FLORAL BIOLOGY OF CUCUMBER ( Cucumis
sativus L.)
Inflorescence
Inflorescence is cymose. Cucumber is monoecious i.e. male and
female flowers present on the same plant. Flowers are
bracteate, pedicellate, unisexual, actinomorphic, pentamerous
and epigynous.
Anthesis
The whole developmental process from the initial bud stage to
the stage when the flower is detached from the pedicel was
divided into 8 stages.
Opening and closing of the male flowers are mainly influenced
by the sunrise and sunset, that is, by light and the time of the
day.
• Anther dehiscence between temperature ranges of 20.5-
21.5°C.
• Pollen fertility was considerable up to noon and by afternoon
(2.00 PM) fertility was greatly reduced, and it was negligible
by evening.
• Stigma receptivity was for very short duration and
pollination should be carried out within 2 hours after
anthesis.
• Rise in temperature causes early drying of stigmatic
secretion. Different floral abnormalities like mixed
inflorescence, hermaphroditism, fusion, dimorphic female
flowers, reduction and increase in the floral parts were
observed.
•
Note the presence of a baby fruit behind the petals. The presence of the
baby fruit indicates it to be a female flower.
FLORAL BIOLOGY OF BITTER GOURD
(Momordica charantia L.)
• Studies on floral biology in Momordica charantia L. showed that
bitter-gourd plants started flowering 40 days after sowing and
blooming period varied from 68 to 76 days.
• The male flower buds took on an average 17 to 19 days, whereas
female buds took 21 to 22 days for their complete development.
• The anthesis started from 4.00 A.M. to 7.30 A.M. and flowers
became fully open from 6.00 A.M. to 9.55 A.M.
• The dehiscence of anthers happened within 6.10 A.M. to 8.55 A.M.
The male flowers dropped off on the same day at 6.00 P.M. to 7.00
P.M., while female flowers withered away next morning.
• Pollen grains of bitter gourd are round in shape. Their size may
vary within the varieties.
• Maximum pollen germination was observed in 20 per cent sucrose
solution.
• The stigmatal receptivity was found maximum at the time of
anthesis, beginning from 8 hours before anthesis and continuing
upto 12 hours after anthesis.
FLORAL BIOLOGY OF BOTTLE GOURD
[Lagenaria siceraria (Mol.)]
• The studies at IIHR, Bangalore, indicate that anthesis starts from
9 am and gets completed by 7 pm the same day.
• Anther dehiscence begins at 11 am and is completed at 2 pm the
same day.
• Stigma becomes receptive 24 hrs before anthesis and remains upto
24 hr after anthesis. Flowers remain open only for a few hours,
after which the petals wither.
• After 24 hrs the stigma loses its shine and becomes brownish and
increases by about 3mm in length, showing the start of fruit
formation.
FLORAL BIOLOGY OF MUSK MELON
(Cucumis melo)
• Flowers are large, yellow, fragrant and edible.
• Many sex forms – monoecious, gynomonoecious,
andromonoecious and perfect – are present in
melons leading to complete allogamy. Melons are
highly cross pollinated and honey bees are the chief
pollinators.
• Time of anthesis – 5:30 – 6:30 am
• Anther dehiscence – 5 – 6 am
• Pollen fertility – 5 am – 2 pm
• Stigma receptivity – 2 hrs before to 2-3 hrs after
anthesis
FLORAL BIOLOGY OF WATERMELON
[Citrullus lanatus (Thumb.)]
• The male flowers open first in the axil of 4th to
12th leaf and a few days later, female and
hermaphrodite flowers open.
• Most flowers open between 5:30 – 7 am. In
watermelon crosses, higher seed set was observed
when pollination occurred in the early morning
immediately after flower opening. Pollen kept at
room conditions for 5 hrs gave a lower seed set
than freshly collected pollen and after 30 hrs
completely lost viability.
FLORAL BIOLOGY OF POINTED GOURD
(Tricosanthes dioca Roxb.)
• Flowering starts from July. Flowers are white. Flower opens
in early morning and closes before sunset.
• Because of dioecy, the crop is highly cross- pollinated.
• Anthers are free, pollen sticky and hence is strictly
entomophilous.
• Male flowers took 16-19 days while female flowers took 10-
14 days from initiation to anthesis (when the anthers and
stigmas first became visible). Anthesis began at 19.00 to
19.30 h in female and at 19.30 to 20.00 h in male flowers.
Stigmas remained viable for 14 and 24 h in open and bagged
flowers, respectively.
FLORAL BIOLOGY OF RIDGE GOURD [Luffa
actangula (L.)]
• The sex forms in ridge gourd are monoecious, androecious,
gynoecious, gynomonoecious, and andromonoecious and
hermaphrodite.
• Flowers open in evening.
• Anthesis occurs between 5 – 8 pm. Anther dehiscence
between 5 – 8 pm. Pollen fertility is maximum on the day of
anthesis and lasts till 2 -3 days after anthesis. Stigma is
receptive 6hrs before to 84 hrs after anthesis.