Studies on seed viability and vigour in ajwain (Trachyspermum copticum L.)
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Date
2012
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
In the present investigation four seed lots of fivevarieties viz., HAJ-13, HAJ-15, HAJ-17,
HAJ-19, and HAJ-22 of ajwain were evaluated for various viability and vigour tests and the
observations were recorded on test weight (g), standard germination (%), seedling length (cm), seedling
dry weight (mg), seedling vigour index-I, seedling vigour index-II, accelerated ageing test (%),
electrical conductivity (µS/cm/g), tetrazolium test(%), dehydrogenase activity test (OD g
-1
ml
-1
), speed
of germination, speed of emergence, field establishment (%) and mean emergence time (days). The
result showed that seed viability and vigour decreased as the increase in storage period in all five
varieties of ajwain. Germination test was standardised and it was concluded that ajwain seeds should be
tested on the top of paper (T.P.) at 20
0
C temperature and final count should be taken on 9
th
day.
Accelerated aging period for ajwain was standardised and it was revealed that ajwain seeds should be
placed in accelerated ageing chamber for 96 h at100% RH and 40+1
0
C temperature. The results also
revealed that Tz test should be conducted as soaking of seed in water for 24 h followed by removal of
seed coat and treating these seeds with 0.5% Tz solution at 35
0
C temperature for 5 h.
Among the different seed lots, varieties which were harvested in 2010-2011 (L4) showed
high viability and vigour followed by those harvested in 2009-2010 (L
3) Among five varieties, HAJ-15
was observed to be highly vigorous and having good storability whereas variety HAJ-19 showed lowest
vigour and minimum storability. Results showed that 18 month old seeds of ajwain retain better
viability and vigour hence it was revealed that ajwain seeds can be stored for 18 months with minimum
loss of viability and vigour. Mean emergence time and electrical conductivity of seed leachates
increased as period of ageing proceed. standard germination, seedling length, seedling dry weight, test
weight, seedling vigour index-I, seedling vigour index-II, accelerated ageing test, tetrazolium test,
dehydrogenase activity test, speed of germination, speed of emergence and field establishment
decreased as period of natural ageing increased in all five varieties. All the parameters were
significantly correlated among themselves except dehydrogenase activity test which is not correlated
with standard germination, speed of germination andmean emergence time. The electrical conductivity
and mean emergence time showed negative significant association with all parameters. Tetrazolium
test, speed of germination, vigour indices, seedling dry weight, and seedling length can be used as
reliable predictors of standard germination, field establishment and mean emergence time in ajwain.
Hence it was concluded that ajwain seeds maintain viability and vigour up to 18 months under ambient
condition.
Description
Keywords
Sowing, Germinability, Developmental stages, Land resources, Vegetables, Electrical conductivity, Seed quality, Drying, Storage structures, Coriander