Analysis of variance of morphological characters
Analysis of variance was conceded on various morphological traits for studying the variation over locations and years. The analysis of variance for the data recorded on various traits viz
. plant height, number of tillers, spike length, number of spike per spikelet, number of grains, thousand grain weights, grain yield, biological yield and harvest index are shown in the Table 2. These results display the differences of climatic conditions prevailing at two locations. Based on the combined analysis of variance, the mean squares of year for all characters were highly significant (P<0.001) whereas significant (P<0.05) for biological yield and number of spikelet per spike. For location, the analysis of variance revealed highly significant (P<0.001) effects for all the characters except harvest index representing the alterations in growth conditions revealed at the two locations. Significant trend was followed by genotypes for all the traits by showing significant differences among them. Significant genetic variation of genotypes recommended that the genotypes were genetically varied and could be a worthy chance for breeders to select genotypes for trait of concern. Numerous investigators reported significant differences between studied genotypes of wheat (Birhanu et al., 2016).
Table 2: Analysis of variance for 09 morphological traits in 100 wheat genotypes.
The interactions between year and genotypes for plant height, tillers numbers, spike length, biological yield, grain yield and harvest index were highly significant while thousand grain weights and number of spikelet per spike were non-significant as there were difference in responses among genotypes during growing years. Similar results were obtained by Mehari et al., (2015)
and Kaya and Turkoz (2016)
. The location and genotype interaction was significant for plant height, spike length, grain yield, harvest index and biological yield. Whereas tillers number, number of spikelet per spike, number of grain, thousand grain weight showed non-significant difference indicating difference in performance of genotype of wheat through the two locations. The difference in genotypes response to the different conditions of environment determines to recognize well performing genotypes for a specific environment. The analysis of variance showed significant variation between genotypes for all the investigated characters. Gharib et al., (2021)
also reported significant difference among studied genotypes. It shows that the material selected for this study brings significant diversity which is required by any breeding program. Similar outcomes were also found by Kaya and Turkoz (2016)
, Mehari et al., (2015).
Genotypic and phenotypic coefficient of variations
To compare the level of degree of difference between numerous characters of plant, phenotypic and genotypic components of variance, GCV, PCV and h2b and genetic advance were analyzed and illustrated in Table 3. At location Rara the GCV and PCV ranged from 4.24% (number of grains) to 16.44% (grain yield) and 4.46% (number of grains) to 17.07% (grain yield). Plant height (9.58 and 9.63%), number of spikelet per spike (8.72 and 9.63%) and biological yield (4.61 and 5.04%) show low values of GCV and PCV while spike length (12.01 and 12.34%), number of tillers (13.75 and 13.17%), thousand grain yield (10.56 and 10.81%) and harvest index (13.76 and 14.01%) show moderate value GCV and PCV.
Table 3: Genetic parameters of 09 traits in 100 wheat genotypes grown in two locations (Rara and Danna of district Muzaffarabad).
At location Danna the GCV and PCV ranged from 4.50% (number of grains) to 14.75% (grain yield) and 4.71% (number of grains) to 15.94% (grain yield) respectively. Spike length (9.55 and 10.27%), number of tillers (11.03 and 13.17%), thousand grain yield (10.24 and 10.45%) and harvest index (12.54 and 12.99%) show moderate value of genotypic coefficient of variance and phenotypic coefficient of variance. Height of plant (9.95 and 10.04%), number of spikelet per spike (9.52 and 10.27%) and biological yield (7.007 and 7.49%) show low values of GCV and PCV.
The present study tells that the phenotypic variation was contributed maximum to the genotypic variations. The phenotypic variation was high as compared to genotypic variation for all characters under study. Overall, the phenotypic coefficients of variance values were higher than genotypic coefficient of variance values while the differences were small. Analogous results were observed by Singh et al., (2018)
representing a smaller influence of environment on the expression of characters considered. Similarly, research was supported out by Kyosev and Desheva (2015)
the phenotypic coefficient of variation were higher than genotypic coefficient of variation for all the characters.
Estimates of heritability
Heritability was assessed for the 09 traits ranged from 82.82 to 98.80% were noted in number of spikelet per spike and height of plant at location Rara and 68.42 to 98.09% were observed in number of tillers and plant height at location Danna (Table 3). Other characters showed high heritability at both location spike length (94.91 and 87.19%), number of grains (89.75 and 91.28%), thousand grain weights (95.47 and 95.66%), grain yield (92.80 and 85.63%), biological yield (83.77 and 87.50%) and harvest index (96.84 and 93.32%) respectively.
In the present study highest heritability (H) was obtained for all traits. High heritability was also described by Tripathi et al., (2015)
for thousand grain weight and Yahaya et al., (2014)
for height of plant. Arya et al., (2013)
was also noted high heritability in plant height. Monpara (2011)
reported high heritability for height of plant followed by number of tillers number, biological yield, spike length, grains number per spike, harvest index and 1000 grain weight. High heritability evaluate for grain yield, number of spikelet per spike, number of seeds per spike, height of plant, 100-seed weight and tillers number per plant were also stated by Adewale et al., (2010)
which support our findings. This showed that these characters were highly heritable and high performing genotypes selection is possible to the development of the characters. High heritability shows less environmental effect in the perceived variation (Eid, 2009)
. The heritability of these characters is due to additive gene effects and choice may be effective in early generations for these traits (Ali et al., 2007)
Estimates of genetic advance (%)
Genetic advance is the progress in the mean genotypic value of selected individual above the parental population. At Rara the genetic advanced expressed as a percentage ranged from 0.02% (biological yields) to 53.45% (number of tiller) (Table 3). Spike length (16.15%) showed the moderate value of genetic advance while plant height (2.83%), spikelet number per spike (9.68%), grains number (3.46%), thousand grains weight (6.07%) and harvest index (6.96%) show low value of genetic advance.
At Danna the genetic advanced ranged from 0.02% (biological yields) to 53.45% (number of tiller). Spike length (14.36%) showed the moderate value of genetic advance while plant height (2.83%), spikelet number per spike (9.63%), grains number (3.47%), thousand grains weight (5.84%) and harvest index (6.68%). In this study the high genetic advance was found for number of tillers all other studied traits show low genetic advance. The results are in close conformity with Safi et al., (2017).
Heritability and genetic development are significant considerations for selection. The assessment of genetic advance is more beneficial for tool choice after measured with heritability evaluations (Johnson et al., 1955).
Low values of genetic advance are indicative of non-additive gene action whereas high values are indicative of additive gene action.