The present research was mainly focused on estimation of genetic variability and character association of
Canna accessions to evaluate the extent of variability.
Estimation of genetic variability
The mean performance is the direct criteria to select the accessions from the diverse population. The mere selection based on the yield related contributing traits may also improve the yield of the population. The trait wise grand mean performance, standard deviation, mean range and coefficient of variation were furnished in the Table 2. To assess the extent of variability, phenotypic and genotypic coefficients of variation are the reliable parameters which will give us the idea of heritable and non-heritable portions of the variability. In the present research study, the higher values of PCV and GCV were less influenced by environment for all the traits. Phenotypic (PCV) coefficient of variation was slightly higher than genotypic (GCV) coefficient of variation for all the traits. High PCV and GCV were found in most of the traits. Phenotypic coefficient of variation ranged from 8.83 to 95.77% and genetic coefficient of variation ranged from 8.49 to 94.95% except in days to first bloom, rhizome diameter and number of nodes per rhizome. Significantly high value for genetic coefficient of variation was recorded in flower yield per plant (94.95%), number of inflorescence per plant (75.62%), single flower weight (60.42%), inflorescence length (57.92%), number of flowers per plant (53.63%), staminode width (49.43%), rhizome fresh weight (45.89%), leaf area(42.35%), plant height (35.11%), number of leaves per clump (33.74%), stem diameter (31.36%), rhizome yield per plant (31.34%), flower length (30.7%), rhizome internode length (27.26%), leaf width (26.97%), number of leaves per plant (25.04%), staminode length (24.42%), leaf length (22.05%), rhizome diameter (21.09%), number of tillers per plant (20.40%), number of nodes per rhizome (15.22%), days to first bloom (8.49%). It indicated that though the characters are least influenced by environmental effect, a phenotypic variability in these characters was contributed by only additive gene inheritance and hence the improvement can be made by simple selection. The similar findings are in accordance with the results in turmeric
(Suresh et al., 2020).
Heritability (h2) and genetic advance as percent of mean (GAM)
All the traits were observed to have high heritability and genetic advance expressed as percentage of mean except in time taken for flowering (16.82%) which were shown medium genetic advances as per cent of mean (GAM) (Table 2). High value to estimate the broad sense heritability were recorded for the characters
viz., Plant height (99.70%) followed by number of flowers per plant (99.40%), number of eyes per rhizome (98.80%), flower yield per plant (98.30%), number of inflorescence per plant (97.70 %), staminode width (97.50%), stem diameter (97.30%), single flower weight (97.10%), rhizome fresh weight (96.30%), flower length (94.40%), rhizome yield per plant (93.50%), rhizome internode length (93.00%), days to first bloom (92.40%), leaf width (92.00%), staminode length (91.70%), inflorescence length (90.40%), leaf length (89.50%), rhizome diameter (87.40%), number of leaves per plant (87.30%), leaf area (86.80%), number of nodes per rhizome (82.00%) and number of leaves per clump (69.60%) and medium heritability were recorded in number of tillers per plant (59.30%). High heritability and high GAM indicates the presence of additive gene action with less environmental influence on these traits and an important factor for predicting the resultant effect for selecting the best accessions. Hence, it indicated the predominance of additive gene action ample scope for improving these traits would be effective for the direct selection. The findings are in accordance with the results of turmeric
(Mishra et al., 2015) and
(Luiram et al., 2018).
Character association analysis
In crop improvement programme, selection is very effective only when genetic variability is present. However, selections for some traits need to be correlated to explain easily the interrelationship among the traits and make easy to identify the elite accessions. Association analysis of different quantitative traits with flower and rhizome yield per plant on
Canna accessions and their interrelationships were investigated though the study of correlation analysis which is suggested that the level of genotypic correlation were higher as compared to their corresponding phenotypic correlations these indicates the inherent relationship and were studied in
Canna (Table 3a and 3b). Among the 23 traits, inflorescence length (0.94**) was highly significant and positively correlated with rhizome yield per plant followed by plant height (0.92**), stem diameter (0.92**), leaf width (0.91**) leaf area (0.85**), number of flowers per plant (0.83**), flower yield per plant (0.83**), rhizome fresh weight (0.79**), rhizome diameter (0.78**), number of tillers per plant (0.76**), leaf length (0.72**), single flower weight (0.66**), flower length (0.62**), number of leaves per clump (0.53*), number of inflorescence per plant (0.52*), staminode length (0.52*), rhizome internode length (0.50*), staminode width (0.41*) while, number of nodes per rhizome (-0.71**), number of eyes per rhizome (-0.70**) were shown negatively correlated with rhizome yield. In the present study, research findings were related and reported in turmeric
(Aarthi et al., 2022) and
(Islam et al., 2008) in ginger.
Stem diameter (0.93**) was highly significant and positively correlated with flower yield per plant followed by single flower weight (0.89**), inflorescence length (0.74**), number of tillers per plant (0.71**), number of leaves per clump (0.70**), number of flowers per plant (0.64**), flower length (0.64**), staminode length (0.63**), leaf width (0.62**), staminode width (0.60**), plant height (0.57**), leaf area (0.48*). Inflorescence length (0.87**) was highly significant and positively correlated with fresh weight of rhizome per plant followed by leaf width (0.81**), stem diameter (0.80**), flower yield per plant (0.80**), number of flowers per plant (0.76**), leaf area (0.72**), rhizome diameter (0.65**), number of tillers per plant (0.64**), plant height (0.60**), single flower weight (0.58**), number of leaves per clump (0.54**), leaf length (0.51*), number of inflorescence per plant (0.46*), staminode length (0.40*), flower length (0.39*), staminode width (0.31*). The result revealed that the related findings were reported in turmeric
(Sivakumar et al., 2020).
Path coefficient analysis
In path analysis were shown direct and indirect effects of ten variable traits on fresh flower yield per plant is given in Table 4. The estimates indicated that the number of leaves per clump (6.22) were exhibited very high and positive direct effect on fresh flower yield per plant followed by fresh rhizome weight (4.81), plant height (3.84), number of nodes per rhizome (3.31) and rhizome intermodal length (1.80). The results in accordance with similar findings reported in turmeric
(Prajapati et al., 2014). The characters stem diameter (-5.93) followed by number of eyes per rhizome (-3.53), leaf area (-2.80), number of tillers per plant (-2.58) and rhizome diameter (-1.63) were shown very high and negative direct effect on fresh flower yield per plant. The research related findings were reported in turmeric
(Suresh et al., 2019).
Considering the indirect effect, all the traits were shown high positive indirect effect on fresh flower yield per plant. Fresh weight of rhizome, number of eyes per rhizome, number of leaves per clump and rhizome internode length were shown very high and positive indirect effect on fresh flower yield per plant while, stem diameter, leaf area, number of tillers per plant, number of nodes per rhizome and rhizome diameter had very high but negative indirect effect on flower yield per plant. The results revealed that both direct and indirect effect play major role in choice of economic trait for selection criteria based on path analysis. The similar results were reported in turmeric
(Verma et al., 2014).