Under laboratory condition results suggested that seed germination and seed vigour were greatly affected by different bio-agents. Among all the bio-agents, PSB showed positive influence on most of the quality parameter and showed significant differences due to varieties, treatments as well as varieties × treatments. However, other bio-agents had also showed significant effect over control. These results indicated that bio-priming caused considerable influence on different varieties of soybean.
Standard germination (%)
Treatment mean was found significant on standard germination (Table 1). The maximum standard germination was recorded for Psf-173 (93.66%) followed by PSB (87.66%) and Psf-173 + Th-14 (84.66%) over control (65.66%).
Different varieties also exhibited significant effect on standard germination (Table 1). The maximum standard germination was recorded in Shilajeet variety (84.80%) followed by PS 1092 (81.60%) and PRS 1 (81.06%) while the minimum was recorded in PK 327 variety (76.80%).
Interaction due to varieties and treatment was also showed significant difference for standard germination (Table 1). The maximum value for standard germination was recorded in Shilajeet variety that was bio-primed with Psf-173 (97.33%) which was statistically at par with Shilajeet variety bio-primed with Psf-173 +Th-14, PS 1092 bio-primed with Pf (93.33%) and PK 327 bio-primed with Psf-173 (92.00 %) while minimum was recorded in uninoculated PK327 (49.33%).
Root length
Treatment mean was found significant for root length (Table 2). The maximum root length was found with PSB treatment (11.01 cm) followed by Psf-173 + Th-14 (10.60 cm) and Psf-173 (9.50 cm) over control (8.72 cm).
Varietal mean showed significant difference for root length (Table 2). The highest root length was recorded in Shilajeet variety (10.83 cm) followed by PS 1092 (9.82 cm) and the least root length was recorded in PRS 1 variety (8.90 cm).
Interaction due to varieties and treatment was also showed significant difference for root length (Table 2). The maximum root length was found in the combination of variety Shilajeet with PSB (12.00 cm) whereas minimum was recorded in uninoculated control (7.52 cm).
Shoot length
Treatment mean was found significant for shoot length (Table 3). The highest shoot length was recorded in PSB (7.96 cm) followed by Psf-173 + Th-14 (7.45 cm) over control (5.57 cm).
Varietal mean showed significant difference for shoot length (Table 3). The maximum shoot length was recorded in Shilajeet variety (7.59 cm) as compared to other three varieties of soybean.
Interaction due to varieties and treatment was also showed significant difference for shoot length (Table 3). The maximum shoot length was recorded in Shilajeet variety when bio-primed with PSB (9.50 cm) and the minimum value was recorded in uninoculated PRS1 (5.67 cm).
S
eedling length
Treatment mean was found significant for seedling length (Table 4). The maximum seedling length was recorded in PSB (18.98 cm) followed by Psf-173 + Th-14 (18.05 cm) and Psf-173 (16.39 cm) over control (14.29 cm).
Varietal mean showed significant difference for seedling length (Table 4). The maximum seedling length was found in Shilajeet variety (18.43 cm) then other three varieties of soybean.
Interaction due to varieties and treatment was also showed significant difference for seedling length (Table 4). The highest seedling length was recorded in Shilajeet when bio-primed with bio-agent PSB (21.50 cm) than the other interactions.
Fresh weight
Treatment mean was found significant for seedling fresh weight (Table 5). The maximum fresh weight was recorded in PSB (8.00 g) followed by Psf-173 + Th-14 (6.95 g) over control (5.14 g).
Varietal mean showed significant difference for seedling fresh weight (Table 5). The maximum fresh weight was found in Shilajeet variety (7.93 g) followed by PS 1092 (7.00 g) and PK 327 (5.82 g) whereas the minimum value for seedling fresh weight was observed in PRS 1 (5.42 g).
Interaction due to varieties and treatment was also showed significant difference for seedling fresh weight (Table 5). The highest fresh weight was recorded in Shilajeet when bio-primed with bio-agent PSB (9.45 g) whereas, minimum was recorded in un-inoculated PK327 (4.30 g).
Seedling dry weight
Treatment mean was found significant for seedling dry weight (Table 6). The maximum dry weight was recorded in PSB (1.31 g) which was statistically at par with Psf-173 + Th-14 (1.23 g), Psf-173 (1.17 g) and Th-14 (1.11 g) over control (0.96 g).
Varietal mean showed significant difference for seedling dry weight (Table 6). The maximum dry weight was found in Shilajeet variety (1.32 g) which was statistically at par with PS 1092 (1.24 g) than the other three varieties.
Interaction due to varieties and treatment was also showed significant difference for seedling dry weight (Table 6). The highest fresh weight was recorded in Shilajeet when bio-primed with bio-agent PSB (1.47 g) whereas, minimum was recorded in uninoculated PRS 1 (0.72 g).
Vigour index I
Treatment mean was found significant for vigour index I (Table 7). The highest vigour index I was recorded in PSB treatment (1666.80) followed by Psf-173 (1538.12), Psf-173 + Th-14 (1531.31) over control (937.33).
Varietal mean showed significant difference for vigour index I (Table 7). The shilajeet variety showed maximum vigour index I (1578.87) followed by PS 1092 (1386.38) and PK 327 (1274.54) whereas, minimum was recorded in PRS 1 (1191.25).
Interaction due to varieties and treatment was also showed significant difference for vigour index I (Table 7). The highest vigour index I was found when Shilajeet bio-primed with PSB (1951.62) which was statistically at par with Shilajeet bio-primed with Psf-173 + Th-14 (1833.49). However, minimum was found in uninoculated PK 327 (834.20).
Vigour index II
Treatment mean was found significant for vigour index II (Table 8). The highest vigour index II was recorded in PSB treatment (115.56) followed by Psf-173 (110.31) and Psf-173 + Th-14 (105.22) over control (63.17).
Varietal mean showed significant difference for vigour index II (Table 8). The Shilajeet variety showed maximum vigour index II (113.85) followed by PS 1092 (101.96) and PK 327 (84.86) whereas, minimum was recorded in PRS 1 (80.46).
Interaction due to varieties and treatment was also showed significant difference for vigour index II (Table 8). The highest vigour index II was found when Shilajeet bioprimed with Psf-173 +Th-14 (133.45) which was statistically at par with shilajeet bio-primed with Psf-173 (133.30) and Shilajeet bio-primed with PSB (133.17). However, minimum was found in uninoculated PRS 1 (50.66).
Seed priming is an important process for the reduction of germination time. It reduces upto 50% time of seedling emergence. Primed seeds enhance seed germination and stand establishment in the field condition due to metabolic enzyme activity. Seed priming techniques are being used to reduce the germination time, synchronize germination, improved germination rate and increase plant stand (
Lee and Kim, 2000). The promoting effects of the different treatments on speed of emergence and field establishment may be due to enhanced hydration of all seed parts and thus reducing the damage of embryonic axis (
Ramadevi and Gopalkrishnan, 2001).
In the present study seed bio-priming enhanced first count, germination percentage, root and shoot length, seedling length, seedling fresh weight, seedling dry weight, vigour index I and II. Seed priming was also reduced time from sowing to germination.
Biopriming of seeds with
Trichoderma harzianum and
Pseudomonas fluorescence 40% concentration for 4 hours enhance the seed quality parameters
(Monalisa et al., 2017).
Bio-primed seeds with different bio-agent showed higher first count and standard germination over control. This might be due to biostimulants and phytohormones produced by microbial inoculants. These findings were in close agreement with
(Begum et al., 2011) in soybean and
(Negi et al., 2005) in pea.
Result of present study revealed that primed seed increase the root and shoot length. Similar finding was also reported by by
Dwivedi and Ram Gopal (2013) in soybean and
Rawat and Prasad (2011) in lentil. The possible reason of root and shoot elongation and increase in seedling length might be due to growth response attributed to IAA production and containing increases amount of phosphorous which uptake with the help of phosphorous solubilizing bacteria (PSB).
In the present study seed bio-primed with PSB showed highest seedling fresh and dry weight. These results are in agreement with finding by
Dwivedi and Ram Gopal (2013) in soybean and
Rawat and Prasad (2011) in lentil. They suggested that increase in fresh and dry weight might be due to production of phytohormones like auxins, cytokinine and gibberellins and also microbial inoculants provides more uptake of nutrient from soil.
Present study also indicated that primed seed had highest seed vigour over uninoculated seed. Such type of finding wee also reported by Dwivedi and Ram Gopal (2013) in soybean and Rawat and Prasad (2011) in lentil. They suggested that vigour of seed indicated the quality of seed and it might be increased by increasing the availability of soluble phosphorous, antagonistic property by phosphate solubilizing bacteria and increase more vigourous plant growth.
It is reported that for germination percentage, primed seeds had lower mean emergence time (MET) compared with non-primed seeds. These positive effects on germination might be due to the stimulatory effects of priming on the beginning times of germination process of germination process by mediation of cell division in germinating seeds
(Hassanpouraghdam et al., 2009). It has been reported that primed seeds showed better germination pattern and higher vigor level than non- primed
(Ruan et al., 2002).