EFFECT OF CLIMATE CHANGE ON FLORAL CHARACTERS IN INBREDS OF MAIZE

1. Agricultural Science Research Journal 3(5); pp. 136- 139, May 2013
Available online at http://www.resjournals.com/ARJ
ISSN-L: 2026 – 6073 ©2013 International Research Journals
Full Length Research Paper
Effect of Climate Change on Floral Characters in
Inbreds of Maize
*V Sandeep Varma, K Kanaka Durga, K Keshavulu, M R Sudarshan and N Sunil
Department of Seed Science and Technology, College of Agriculture, Rajendranagar, Hyderabad- 500 030, A.P.
*Corresponding author email: sandeepvunnam81@gmail.com
ABSTRACT
The result of an experiment to study the effect of various climates on floral characters in hybrid seed
production of maize showed that days to first pollen shed was more (66.3) when maize was sown during
first fortnight of June (01.06.2012), while the maize crop sown during the second fortnight of August
(15.08.2012) took minimum days for the first appearance of tassel. High pollen viability (97.5 %) was
observed when the temperature was more i.e. 28.06 º C, where as the viability of pollen was less during
low temperatures of 26 ºC, high relative humidity (88 %) and high rainfall (12.6 mm). The total number of
pollen shedding spikelets per tassel was more (757.8) during the first fortnight of June (01.06.2012),
where relatively high temperature (27.6 ºC) was present. With respect to silk characters, crop sown on
second fortnight of June (15.06.2012), which coincide with high temperature of 28.06 ºC, took
comparatively less number of days to first silking (56.7) and at the same time, it took more days to
complete 50 % silking (72.3). The total number of silk per cob (574.4) was relatively more during high
temperature conditions. So, it clearly reveals the influence of various climatic factors like RH,
temperature and rainfall on floral characters of maize.
Keywords: Climate Change, Maize, Inbreds, Tassel and Silk Characters.
INTRODUCTION
Maize (Zea mays L., 2n=20) occupies third position
among the cereal crops after paddy and wheat in world. It
is the most versatile crop with wider adaptability in varied
agro-ecologies. The global warming and climate change,
will drastically effect the production and productivity of
food crops. Global warming will significantly effect on the
development, growth, and yield of plants particularly
seed-producing food crops. Also, the effects of global
warming will vary depending on the climatic conditions at
various locations on the earth (Thomas and Prasad,
2003). Environmental changes associated with different
sowing dates (sunshine, temperature) have a modifying
effect on the growth and development of maize plants. In
a flower, male (pollen) and female (ovule) gametes
function to recombine genetic information and produce
seed for the next generation of plants. Temperatures
above the optimum can exert negative effects on plant
reproductive development. Pollen production and pollen
viability are very sensitive to slight increases in
temperature above the optimum (Thomas and Prasad,
2003). In India, various climatic conditions prevail, which
makes very difficult to know the exact effect of climatic
change on floral characters. Therefore this study was
initiated to reveal the effects of various climatic factors
such as temperature, rainfall and relative humidity on
floral characters of maize and provide more information
for further utilization in seed production and breeding
programs.
MATERIALS AND METHODS
An experiment was conducted during rainy season, 2012
at Seed Research and Technology Centre,
Rajendranagar, Hyderabad. Female and male parents of
DHM 117 i.e. BML 6 and BML 7 were sown in 4:1 ratio, at
different sowing dates with fortnightly intervals i.e. 01-06-
2012, 15-06-2012, 01-07-2012, 15-07-2012, 01-08-2012

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Table 1. Mean of temperature, rainfall and relative humidity at different sowing dates of maize
Dates of sowing Temperature (ºC) Rainfall (mm) Relative humidity (%)
01/6/2012 27.60 0.30 60.33
15/6/2012 28.06 8.99 82.93
01/7/2012 27.30 4.00 81.00
15/7/2012 26.00 12.60 88.00
01/8/2012 26.40 1.70 87.00
15/8/2012 26.30 4.60 86.00
Table 2. Mean data for various tassel characters of male parent (BML 7) of maize hybrid DHM 117
Dates of
sowing
Days to first
pollen shed
Days to 50 %
pollen shed
Tassel
length (cm)
Pollen viability Pollen shedding
spikelets
Total spikelet
branches9 AM 2 PM
01/6/2012 66.3 68.0 31.1 96.7 96.3 757.8 13.3
15/6/2012 60.7 64.7 30.2 97.5 93.9 617.7 11.2
01/7/2012 65.3 69.7 33.2 93.2 85.6 675.3 12.1
15/7/2012 65.7 68 33.1 90.7 83.1 503.8 9.0
01/8/2012 62.7 75.3 32.3 95.4 92.6 669.6 12.8
15/8/2012 57.3 60.7 29.0 97.2 96.5 664.7 10.9
G. Mean 63.0 67.72 31.41 95.13 91.33 648.13 11.52
C.D 2.48 2.61 1.93 2.81 3.99 194.61 3.612
C.V % 2.16 2.11 3.38 1.62 2.40 16.49 17.21
Table 3. Mean data for various silk characters of female parent (BML 6) of maize hybrid DHM 117
Dates of sowing Days to first silking Days to 50 % silking Silk emergence per period
01/6/2012 59.3 70.7 521.1
15/6/2012 56.7 72.3 574.4
01/7/2012 67.5 70.0 573.3
15/7/2012 61.5 68.7 538.5
01/8/2012 59.7 71.3 642.9
15/8/2012 54.3 59.8 542.7
G. Mean 59.72 68.88 567.68
C.D 3.48 2.09 82.62
C.V % 3.20 1.66 7.99
and 15-08-2012. The experiment was laid out in
randomized block design with three replications.
Integrated crop management practices were followed to
raise a healthy crop. Observations were taken at regular
intervals for tassel characters including days to first
pollen shed, days to 50 % pollen shed, pollen viability (at
9 AM and 2 PM), tassel length, number of pollen
shedding spikelets per tassel and total spikelet branches
and similarly silk characters like days to first silking, days
to 50 % silking and total silk emerged per cob on five
randomly selected plants per each replication for
assessing various climatic effects on tassel and silk
characters.
RESULTS AND DISCUSSION
The meteorological data (temperature, rainfall and
relative humidity) during planting period at fortnightly
interval were collected and presented in Table 1. The
effect of various climatic factors i.e. variation in
temperature, relative humidity and rainfall on floral
characters in maize as shown in Table 2 and Table 3,
revealed that days to first pollen shed was more (66.3)

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Figure 1. Effect of temperature on pollen viability at different sowing dates
when maize was sown during first fortnight of June
(01.06.2012), while the maize crop sown during the
second fortnight of August (15.08.2012) took minimum
days for the first appearance of tassel (57.3). The data in
Table 2 revealed that temperature had more effect on
pollen viability. High pollen viability (97.5 %) was
observed when the temperature is more i.e. 28.06 º C,
where as the viability of pollen is less during low
temperatures of 26º C, high relative humidity (88 %) and
high rainfall (12.6 mm). Pollen viability depicted in Figure
1 reveals that the pollen viability was more in early
plantings and it was slowly decreased by later sowings
and increased by late sowing. It was correlated with lower
temperatures (27.60 °C) followed by higher temperatures
(28.06 °C). So, it clearly reveals the influence of climatic
factors like RH, temperature and rainfall on pollen
viability. This is in conformity with the findings of Schoper
et al. (1986) who reported the effect of temperature on
pollen viability in maize. Similarly, Vara Prasad et al.
(2006) also reported that growth temperatures beyond
36°C significantly decreased pollen production and pollen
viability in grain sorghum. Lower pollen viability at high
temperatures could be related to degeneration of tapetum
layer (Suzuki et al., 2001), and/or decreased
carbohydrate metabolism (Datta et al., 2001; Pressman
et al., 2002; Karni and Aloni, 2002), all of which could
significantly influence nourishment of pollen mother cells
there by leading to infertile pollen.
During second fortnight of June (15.06.2012), although
pollen viability (97.5% at 9 AM) was high, the length of
the tassel (30.2 cm) and total spikelet branches (11.2)
were comparatively less due to presence of high
temperatures (28.06 °C). The total number of pollen
shedding spikelets per tassel was more (757.8) during
the first fortnight of June (01.06.2012), where relatively
high temperature (27.6 ºC) was present. It is interesting
to note that, the total number of pollen shedding spikelets
per tassel was less (503.8) during the second fortnight of
June (15.06.2012), which coincide with low temperature
i.e. 26º C. Further it is observed that at medium
temperatures i.e. 26.30 ºC which were prevailed during
second fortnight of August, the number of days for first
pollen shed was very less (57.3), and comparatively more
pollen viability was recorded at morning times i.e. at 9 AM
(97.2 %) and also at 2 PM (96.5 %) which had a great
influence on seed setting consequently leading to higher
seed yields..
With respect to silk characters (Table 3), crop sown on
second fortnight of June (15.06.2012), which coincides
with high temperature of 28.06 ºC, took comparatively
less number of days to first silking (56.7) and at the same
time, it took less days to complete 50 % silking (72.3).
The total number of silk per cob (574.4) was relatively
more during second fort night of June, where high
temperature conditions (28.06 °C) were prevailed.
By observing the data from Table 2 and 3, it was

4. concluded that the crop sown during the second fortnight
of August (15.08.2012) took less number of days to
pollen shed (57.3), 50 % pollen shed (60.7), first silking
(54.3), 50 % silking (59.8) and relatively more pollen
viability (97.2 % at 9 AM) where the optimum
environmental conditions like moderate temperature
(26.3 ºC) coupled with medium rainfall (4.60 mm) and
high relative humidity (86 %) were prevailed. It was
clearly revealed the effect of extreme or deficient
conditions of environment on the floral characters of
maize which in turn influenced the seed yield.
CONCLUSION
Temperature had drastic effect on tassel characters like
pollen viability, days to first pollen shed, tassel length and
number of pollen shedding spikelets. At high
temperature, the tassel length (30.2 cm), days to first
pollen shed (60.7), days to 50 % pollen shed (64.7) and
days to first silking (56.7) was reported relatively less,
where as pollen viability (97.5 %) was more at high
temperatures because of variations in rainfall and RH. At
low temperature conditions i.e. at 26º C, the pollen
viability (90.7 %), number of pollen shedding spikelets
(503.8) and days to 50 % silking (68.7) was less.
However, for successful planting, farmers must rely
heavily on meteorological weather forecast most
especially that the world is experiencing climatic change
phenomenon.
139
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