Introduction
High quality seed is a prerequisite for higher and reliable yield of crops.
Germination is the emergence and development from the seed embryo of those essential
structures which for the kind of seed being tested. It indicates the ability
to develop into a normal plant under favorable conditions in the soil ( ISTA,
1976 ). Usually laboratory germination tests are used to obtain a general indication
of capacity of seeds to produce plants in the field. High germination percentage
may not be necessarily in good plant stand and establishment rather high germination
percentage raises high expectation of field emergence. Seed vigour determine
the potential for rapid, uniform emergence and development of normal seedling
under a wide range of field conditions (McDonald, 1980). Germination in a favorable
condition is the physical expression of a seed lot on question of its viability.
However, mare germination test cannot quantitate the quality of the seed. There
are several tests available to estimate seed vigour of which speed of germination,
hot test, cold test etc. are mach in use (ISTA, 1987). There is lack of information
about farm level seed lots of different location specific jute seed quality
potential tests. In that respect an experiment was conducted with jute seed
to verify their performance in viability, vigour and other seed potential tests.
Materials and Methods
The experiment was conducted at Agronomy Laboratory, Bangladesh Jute Research Institute, Dhaka during the year 1999-2000. Seeds of two jute species (Corchorus capsularis and C. olitorius) were used as crop materials. Among the four locations Manikgonj and Kishorgonj were specified for capsularis and Foridpur and Rangpur for olitorius jute. Seed samples were collected from twelve different jute seed lots of each Corchorus species and of six from each location. Germination not less than 80% and about 9-10% moisture content were allowed at the time of seed samples used.
The tests of viability, vigour and other tests for seed potentiality were done by different methods as follows:
Viability/Germination test
Laboratory standard germination test: One hundred seeds of each replicated
sample were allowed to germinate on top of a filter paper in 5ml. tap water
in plastic petri dishes. The test was conducted in an incubator at 30±1
0 C. The germination was recorded after 120 hours and then calculated
the germination percentage (ISTA, 1966).
Pot-culture test: Fifty seeds of each replicated sample were sown in a 30cm. earthen pot. The earthen pots were filled with farm soil and watered regularly. Total germination per sample was calculated after 7 days.
Vigour test
Speed of germination test: The test was conducted in laboratory with
the same procedure as laboratory standard germination test. Vigour (Vigour value)
was calculated following (Jain and Saha, 1971) V=a/1+b/2+c/3+………where,
V=Vigour value, and a, b and c are the number of seeds germinated after 1, 2
and 3 days. The final count was made at the end of 5th day.
Hot and cold test: Hot and cold tests were also conducted in the incubator. The temperature for hot test was 40 0 C and for cold was 20±2 0 C. Each of every replicated samples seed germination was calculated after 48 hours for hot test and 120 hours for cold test (ISTA, 1987).
Other potentiality tests
Germination after 48 hours: This test was same as laboratory standard
germination test however, the final count of germinated seeds were made after
48 hours.
Rate of germination: The rate of germination was calculated using the following formula of Krishnasamy and Seshu (1990)
Complete Randomized Design (CRD) with five replications was followed in each test and the data were statistically analyzed by Gomez and Gomez (1976).
Results and Discussion
In C. capsularis the interaction between seed lots and locations were
significant in pot- culture, speed of germination, hot test and germination
after 48 hours. The highest pot culture of 75%, speed of germination of 64%,
hot test of 68% and germination after 48 hours of 78% were found at Manikgonj.
However viability, cold test and rate of germination showed insignificance.
The highest germination in pot-culture was 75% in Manikgonj and lowest 55% was
also found at the same location.
| Table 1: |
The interaction effect of different seed (Corchorus capsularis
L) lots of different locations in different seed potentiality tests |
 |
| NS=Non significant |
| Table 2: |
The interaction effect of different seed (Corchorus olitorius
L) lots of different locations in different seed potentiality tests |
 |
| NS=Non significant |
| Table 3: |
Performance of different seed potentiality tests at different
locations for C. capsularis and C. olitorius |
 |
| NS=Non significant |
| Table 4: |
Correlation coefficient of different seed potentiality tests
in Corchorus capsularis |
 |
| *, ** significant at 1 and 5% level of significance |
| Table 5: |
Correlation coefficient of different seed potentiality tests
in Corchorus olitorius |
 |
| *, ** significant at 1 and 5% level of significance |
The highest value by speed of germination showed 64 at Manikgonj and lowest
49 was at Kishorgonj. The highest germination after 48 hours (78%) was observed
at Manikgonj and lowest 64% was collected from Kishorgonj (Table
1). These results confirmed the earlier report (Islam, 1997).
In C. olitorius the interaction between seed lots and locations differed significantly in pot culture, speed of germination, hot test and germination after 48 hours). However, laboratory standard germination, cold test and rate of germination were insignificant. The highest values of pot culture, speed of germination, hot test and germination after 48 hours were 76, 57, 74 and 85% ; and the lowest values were 58, 47, 55 and 71% respectively (Table 2). The results are in agreement with Wang and Hampton (1989). They stated that germination did not differ significantly among the six seed lots of Red clover and ranged from 88 to 92%. Happ (1993) stated that standard germination results showed no significant difference in germinability among the three perennial ryegrass (Lolium perenne L. ).
The vigour tests (Speed of germination, hot test and cold test) and other potentiality test (germination after 48 hours) differed significantly due to locations (Manikgonj and Kishorgonj for C. capsularis). However, in case of viability tests ( laboratory standard germination and pot- culture), hot test and rate of germination the locations showed insignificant results. The highest values of speed of germination, hot test, cold test and germination after 48 hours were 60% (Manikgonj), 57%(Manikgonj), 21%(Kishorgonj) and 63%(Manikgonj) respectively. Similar results were found in case of C. olitorius, where Faridpur and Rangpur were the two locations. Speed of germination, hot test and cold test and germination after 48 hours differed significantly due to location. Laboratory standard germination, pot- culture and rate of germination were insignificant. The highest values of speed of germination, hot test and cold test and germination after 48 hours were 54, 64, 25 and 76% in Rangpur respectively (Table 3). Islam (1996) also revealed the similar results.
In C. capsularis the correlation coefficient of laboratory standard germination with pot culture, hot test, and cold test were significant. The correlation with rate of germination was significant but negative. The coefficient of laboratory standard germination with speed of germination and germination after 48 hours were insignificant. All other correlation coefficients among different potentiality tests were significant except cold test with germination after 48 hours and negative insignificant coefficient was found in germination after 48 hours with rate of germination. It was indicated that the correlation coefficients of rate of germination with all other tests were negative. Among the correlation combinations the highest coefficient of r=0.98** was found in pot culture with hot test and followed by pot culture with cold test r=0.96 and pot culture with laboratory standard germination of r=0.88 (Table 4). These results are in agreement with Egli and Tekrony (1995).
In C. olitorius the correlation coefficient of laboratory standard germination with pot culture, hot test, cold test, and germination after 48 hours were significant. Rate of germination with laboratory standard germination was significant but negative. Only speed of germination showed insignificant correlation coefficient with laboratory standard germination. All other correlation combinations showed significant coefficients except cold test with germination after 48 hours. Similar performances were found in case of correlation in rate of germination with all other potentiality tests, were negative. The highest correlation coefficient of r=0.97 was found at the combination of laboratory standard germination with pot culture, followed by r=0.94 of speed of germination with hot test and r=0.92 of pot culture with cold test (Table 5). These results are also in agreement with Egli and Tekrony (1995).
From the above results, it can be concluded that different seed potentiality tests, laboratory standard germination than pot-culture in viability test, hot test followed by speed of germination and cold test in vigour test and rate of germination than germination after 48 hours in other seed potentiality tests showed better performance. In both the jute species the correlation coefficient between laboratory standard germination with pot-culture, hot test and cold test were higher and significant.
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