Considering the diverse seed priming with 12 treatments (T
1-T
12) including control (without treatment), the observations were related to physiological performances of seed on three genotypes (V
1, V
2 and V
3) of French bean. The explanations were regulated to facilitate the seed quality associated to seedling parameters and biochemical activity in two successive years and pooled value. The various treatments showed significant variances for all considerable parameters which were clustered into two different kinds like seedling parameters and biochemical parameters. In application of diverse priming mode, the variable significant distinction showed advancement, similar to observation of other researchers
(Ghobadi et al., 2012 and
Abnavi et al., 2012) predominantly the pooled values. The superior treatment values over control emphasized the positive effect of priming, as seen in T
2 (thiourea @700 ppm) though it was variable in peroxidase activity and first year values of germination percentage (Table 1). The observed values on germination percentage were transformed into arcsine value for statistical calculation. In percent of germination, T
6 (KNO
3@0.2 Mpa) was highest only for 1
st year and the peroxidase activity showed a positive response when treated with T
3 (50 ppm gibberellic acid) followed by T
11 (distilled water), T
5 (0.1 Mpa KNO
3) and T
2 (750 ppm thiourea) under both year with pooled analysis. The anti-oxidative nature of peroxidase may favour the physiological aspect of seed, predominantly in germination. Normally, the role of bio-regulators is known for augmenting seedling expansion, mounting photosynthetic efficiency
(Ramaswamy et al., 2007) etc. for emerged seedling.
Analysis of variance showed that all parameters were significantly influenced by seed priming for all the genotypes where speed of germination, vigour index and the enzyme, alpha amylase were predominant. The highest values were seen in V
3 (RCM-FB-62) genotype for vigour index, alpha-amylase and non-significant deviation with the highest for seedling dry weight considering both years and pooled analysis (Table 2). In germination percentage, the V
2 (Phyrngop dwarf) genotype showed highest for 1
st year but, V
3 (RCM-FB-62) indicated its dominance for 2
nd year and pooled assessment (Table 2). The priming treatment might have an effect on peroxidase activity where V
3 recorded lowest value as compared to other genotypes as specific genotypic nature was the most dominant factor. Considering the findings on speed of germination and seedling length, the genotype V
1 exposed greater values among various genotypes. The important parameters vigour index and alpha-amylase under physiological performances of seed showed greater performance in V
3 genotype, though it was not truly followed in seedling dry weight. In peroxidase activity, the observation was contrary to previous two parameters. Hence, these parameters may be considered for genotype evaluation.
In interaction of treatment and genotype, the significant enhancement was noticed for parameters only in enzymatic actions considering both years and pooled analysis, but the non-significant trend was followed for most of the seedling parameters in full or partial manner except in seedling length (Table 2). Considering all parameters, the observed interacted values showed a general trend for upgradation in interaction of various priming over control
(Lamichaney et al., 2018) irrespective of genotypes.
In Fig 1, the effect of treatment was visibly progressive for scheduled parameters considering their percent of enhancement over the control (T
12). But, the activity of peroxidase demonstrated variable nature, highlighting highest effect in T
3 with intermediate action in T
2, T
6 and T
11. The most promising effect was observed in speed of germination, seedling dry weight and alpha amylase activity.
The effect of primed seeds exposed a pronounced demarcation over control for most of the traits in the current study. It was reported that priming modified the metabolic processes involved in germination and earlier establishment of seedlings
(Ghassemi-Golezani et al., 2008) as well as plants which may elicit the early development in comparison to control (
Emongar, 2007). Moreover, the enzymatic action at initiation of germination may also be beneficial to advance seed vigour through sharing its expanding dry weight and length of the seedling
(Arun et al., 2017).
In correlation matrix of the different physiological performances of seed, the R
2 value of 0.7352 (Table 3) denoted the usual significant positive relationship for considerable characters. The positive significant mode was observed for most of the characters though the exception was revealed in peroxidase activity. The non-significant relationship was also followed in per cent of germination with seedling length, seedling dry weight and alpha-amylase activity though other parameters were highly significant within them in positive mode. All values of negative correlation showed non-significant differentiation particularly in case of peroxidase. However, peroxidase activity only showed a positive correlation with germination percentage, similar to a study by
El-Araby et al., (2004). Therefore, the activity of peroxidase may favour germination by reducing antagonistic effect in seed, while alpha-amylase activity is closely related to germination activity. The adaptation of seed quality through priming and its effect on seedling parameters was studied by different scientists (
Abnavi et al., 2012;
Lamichaney et al., 2018). The dissimilar physiological performances of seed may diminish or increase in various ways through utilization of diverse treatments on seed in different crops, particularly under legumes and cereals. But seedling dry weight always showed an increase on application of PEG 6000
(Ghobadi et al., 2012), thiourea (
Khan and Shah, 2010) KNO
3 (
Kumar et al., 2018), GA
3 (
Abnavi et al., 2012;
Arun et al., 2017;
Mahnaz and Masomeh, 2016) similar to our study and sometimes in presence of CaCl
2 (
Afrayeem et al., 2018) and water as hydropriming (
Mahnaz and Masomeh, 2016). Thiourea was the most capable sulphydryl group (-SH) of bio-regulator helpful in seedling growth
(Anese et al., 2011 and
Premaradhya et al., 2018). The intensity in activity of super-oxide dismutase (SOD) and quantity of soluble protein was amplified in radish owing to the effect of thiourea
(LiQin et al., 2001). Growth promoters and nutrients directly influence metabolic activities in leaves during plant development and are thus responsible for improving the quality of the seed at the time of seed development. The potency of priming may enhance the activity of peroxidase, catalase, SOD and minimize electrolyte leakage under soaking.
Generally, germination and interrelated parameters involve the activities of enzymes/isozymes, where anti-oxidative activity of specific isozymes is closely related to germination. A few reports relating to the valuable priming effects on seed indicated a build-up of more metabolites or osmotic adjustments at germination through the restoration of metabolic processes
(Elkoca et al., 2007), or upgraded membrane integrity and superior physiological activities at germination (
Sung and Chang, 1993). Soaked seed through hydro-priming or other modes of priming can supplement biochemical action like soluble protein, lipid, sugars, vitamin E, pro vitamin A
etc. to bear the fundamental capability responsible for germination
(Janeczko et al., 2015). Estimation of peroxidase activity can be used as an indicator of seed quality as reports have shown a sharp decline during aging
(Pallavi et al., 2003). Seed treatment with thiourea has also been reported to enhance germination
(Wahid et al., 2017) as observed in the present study.
