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Genetic variability in wheat for staygreen character and its association with grain growth under normal and late sown conditions

KrishiKosh

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Title Genetic variability in wheat for staygreen character and its association with grain growth under normal and late sown conditions
 
Creator Ahlawat, Shweta
 
Contributor Chhabra, Ashok
 
Subject Staygreen, Grain growth, Photosynthesis, Chlorophyll, Senescence
 
Description High temperature has a marked effect on cellular processes, growth
development and economic yield of wheat plants. Large proportion of wheat area in
India is planted after the first week of December (late sown) that warms up towards
the grain filling stage of the crop there by leading to significant yield losses due to
heat and water stress created by increased temperatures. In such situations, wheat
genotypes which could sustain grain growth over longer post anthesis span or further
deposition of carbohydrates in grain sink would prove promising. So, to sustain wheat
productivity, research emphasis has been given to develop genotypes which could
staygreen along with larger leaf area and high relative water content so that they can
carry out photosynthesis for a longer period as compared to the normal senescent
cultivars and thereby enhancing yield.
Genetic analysis of grain yield and its components were conducted on thirty
six elite genotypes of wheat. The material was grown in randomized block design with
three replications at CCS Haryana Agricultural University, Hisar, Research Farm
under two natural photothermal environments created through alteration of dates of
sowing i.e. 23rd November 2004 and 10th January 2005. Beside field experiments, lab
experiment on chlorophyll estimation, AGPase enzyme activity and RAPD markers
were also conducted.
Under field experiment, relationships of some morphophysiological traits and
heat tolerance were examined. Our data showed significant variations among wheat
genotypes under stagger sowing for there character expression, particularly days to
flowering, grain growth, biomass, grain yield staygreen. Delayed leaf senescence
showed significant positive correlation with yield under then condition (late sown).
Among the other traits, higher biomass at harvest, more 1000 grain weight, faster
grain growth rate, chlorophyll content were also found to be associated with yield
under heat stress conditions. Two genotypes MLU-2 and WH147 M expressed the
strongest staygreen trait. These plants were staygreen even in the month of May when
the high temperature led to moisture stress conditions. AGPase enzyme was being
assayed to determine relationship between staygreen, starch metabolism and grain
development in early, late planting. These genotypes could be used as candidate
‘plants’ for isolating genes governing delayed monocarpic senescence. However, the
staygreen character can be transferred to genotypes having fast growth so that their
early senescence in rainfed and late sown conditions may be avioided and sustained
growth could be achieved by combining staygreen post anthesis translocation of
carbohydrates to grain sinks.
 
Date 2016-12-01T14:27:07Z
2016-12-01T14:27:07Z
2005
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/88672
 
Language en
 
Format application/pdf
 
Publisher CCSHAU