Photosynthetic rate studies in Indian mustard (B. juncea (L.) Czern & Coss.)
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Date
2013
Authors
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Journal ISSN
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Publisher
CCSHAU
Abstract
The objectives of present investigation were to the study photosynthetic rate of wild and
cultivated variety of B. juncea and to compare photosynthetic rate of hybrids with their respective
parents. The characters observed were net photosynthetic rate, transpiration rate, stomatal conductance,
intracellular CO2
concentration, water use efficiency, mesophyll efficiency, chlorophyll content and
seed yield per plant were recorded. Result revealed that average net photosynthetic rate was maximum
in 5
th
upper leaf, whereas average stomatal conductance was maximum in 3
rd
upper leaf and
intracellular CO2
concentration at 1
st
lower most leaf at 45 (DAS). At varying light interception, net
photosynthetic rate and transpiration rate was found maximum at 12:00 PM. However intracellular CO
2
concentration was maximum at 10:00 AM. Intracellular CO2
concentration was found to be positive
and significantly correlated with transpiration rate, stomatal conductance and chlorophyll content.
Significant differences for photosynthetic traits indicated the ample variability existed among the
genotypes. The estimate of heritability were high for the characters- water use efficiency and
mesophyll efficiency, whereas low to moderate genetic advance was observed for the characters net
photosynthetic rate and chlorophyll content. High heritability coupled with high genetic advance was
observed for seed yield per plant and stomatal conductance. The highest mean over parental heterosis
was observed in Kranti x RB-50 for transpiration rate (95.18%) and intracellular CO
2
concentration
(67.82%). The overall performance of the crosses Kranti x RH-0446, Kranti x RB-50, RH-9304 x RH-8113, RB-50 x RH-9304, RH-0446 x RH-8113 were found promising and may be exploited in future
breeding programme in order to improve the photosynthesis and seed yield in mustard.
Description
Keywords
Indian mustard, photosynthetic traits, genetic diversity, heterosis