Floral Biology and Fruit Setting
Studies in Chile.
Ashish Saxena and Jarnail S Hundal
PAU, Ludhiana
33o
NMSU, Las Cruces
Punjab
Agricultural
University,
Ludhiana
(www.pau.edu)
Punjab state
Punjab
Agricultural
University,
Ludhiana
(www.pau.edu)
Punjab state
Capsicum annuum L. in Punjab
 Important cash crop
 fresh market
 processing industry.
 Higher net returns
 diversification from
paddy (Oryza sativa L.)
wheat (Triticum aestivum L.)
 Excellent performers (hybrids)
 CH 1
 CH 3
Existing problem
 Required quantity of
hybrid seed was not
available.
 Available seed quality
was poor due to low
germination per cent.
 Hybrid seed production
is problematic.
Floral Biology
 Study of life of flowers which
includes initiation and anthesis of
flowers, dehiscence of stamens,
receptivity of stigma and
development of fertilized ovary.
 Thorough knowledge is a pre
requisite for embarking upon a
crop breeding and hybridization
program.
 Floral-biology of chile changes
across different locations.
Seasonal variation
 Environment plays a pivotal
role in fruit and seed
formation.
 Temperature and relative
humidity (RH) are the
major contributing factors.
 Effects of climatic factors on
floral biology, seed yield and
seed quality are not well
known.
So…
Objectives
Optimize F1 seed production through other
restorer lines
Determine impact of environment on seed
production.
How ???
Determine:
 Pollen viability of male parents.
 Fruit set of restorer lines when crossed with GMS
(Genetic Male Sterile) line.
 Seed germination of F1 seeds
» Monthly during peak flowering season
(June to September).
Materials
&
Methods
Genotypes
Female
MS 12
(Genetic Male Sterile)
(1:1 male : female)
Restorer Lines
X
I 16
LLS
Pepsi 8-1
PS 4221
Punjab Guchhedar
S 2529
S 2530
S 2545
Identification of female in GMS
Character Male fertile Male sterile
Pollen
Present
Absent
Anther Color Light Grey
Purple or Yellow
Anther size
Normal
Reduced to less than
half
Anther
dehiscence
Present
Absent
Fruit set
Heavy
Low to medium
depend upon allogamy
Identification of female in GMS
Character Male fertile Male sterile
Pollen
Present
Absent
Anther Color Light Grey
Purple or Yellow
Anther size
Normal
Reduced to less than
half
Anther
dehiscence
Present
Absent
Fruit set
Heavy
Low to medium
depend upon allogamy
Uprooted before hand pollination
Identification of female in GMS
Character Male fertile Male sterile
Pollen
Present
Absent
Anther Color Light Grey
Purple or Yellow
Anther size
Normal
Reduced to less than
half
Anther
dehiscence
Present
Absent
Fruit set
Heavy
Low to medium
depend upon allogamy
Used for hand pollination as female
Pollen load
Collection of freshly opened flowers
Dehisced pollen dissolved in 1 μ L of dH2O with vertexer
Pollens counted on hemocytometer
Pollen viability
Collection of freshly open flowers
Dehisce anthers at room temperature
Preparation of glass slides with pollen and fresh TTC*
Slides placed in dark for half an hour
Observed under compound microscope for red staining
Viable pollen
* (2,3,5 triphenyl tetrazolium chloride)
Fruit set
Identification of female plants in GMS line
Hand pollination of 50 buds at 4 different periods by all 8
restorer lines separately
Counting of fruits set after 5 days of crossing
Four different periods are:
[-12, 0, +12 and +24 h after anthesis]
Seed germination
Collection of crossed seeds from female plants
25 seeds in 3 replications of each cross were placed on
moist germination paper
Placed in incubator at 25±10 C for 14 days
Counting of germinated seeds
Statistical Analysis
Randomized complete block design was used to analyze
the data obtained from experiment.
The data were pooled over different months to obtain
useful results.
CPCS 1 computer program was used for statistical
analysis.
Observations
Pollen load
4
3.5
Millions
3
2.5
2
1.5
1
0.5
0
I 16
LLS
Pepsi
8-1
PG
PS
4221
S 2529 S 2530 S 2545
Restorer lines
Stigma receptivity after anthesis
50
45
40
35
30
% 25
20
15
10
5
0
-12h
0h
Time
+12h
+24h
Pollen Viability
80
70
b
60
b
50
% 40
c
b
a
d
e
c
30
20
10
0
I 16
LLS
LSD0.05 = 2.0
Pepsi
8-1
PG
PS
4221
S 2529 S 2530 S 2545
Restorer lines
Fruit setting
60
50
a
% 30
b
b
40
c
f
d
e
20
c
d
c
d
e
10
0
I 16
LSD0.05 = 3.9
LLS
Pepsi 81
PG
PS
4221
S 2529 S 2530 S 2545
Restorer lines
Seed germination
90
a
80
70
60
%
50
e
d
e
e
f
c
d
b
b
c
40
30
20
10
0
I 16
LSD0.05 = 4.6
LLS
Pepsi
8-1
PG
PS
4221
S 2529 S 2530 S 2545
Restorer lines
Fruit set vs. Environment
80
Fruit set %
70
60
50
40
30
20
10
temp
rh
0
30
40
50
60
Temperature & RH
70
80
Seed Germination vs. Environment
Seed Germination %
120
100
80
60
40
20
temp
rh
0
30
40
50
60
Temperature and RH
70
80
Results I
 Maximum fruit set was observed when crossing was
done at the time of anthesis.
 S 2529 had highest pollen load and pollen viability,
but lower fruit set prevent this restorer line to consider.
 Punjab Guchhedar was the best restorer line for fruit
set with highest germination of F1 seeds, despite lower
pollen viability.
 Significant genotype and environment interaction was
observed.
Results II
 Environment seems to play negligible role in
determining the pollen viability.
 Fruit set and seed germination ability greatly
influenced by the temperature and relative humidity.
 Average monthly temperature of 30oC and 82% RH
gave highest fruit set.
 Highest seed germination was observed at 29oC and
70% RH.
Conclusion
 Punjab Guchhedar was the only restorer line
performed consistently across different temperature
and RH regimes from June to September months.
 June and July months were found to be better for
seed production of CH 1 hybrid.
 August and September months were found to be
better for seed production of CH 3 hybrid.