The analysis of variance (ANOVA) for yield, yield contributing and quality traits are presented in Table 2. The resultsrevealed highly significant differences among the genotypes for all the traits under study, indicating the existence of adequate variation in experimental material. Thus, there is a good opportunity to select better parental types to improve grain yield and quality.
A perusal of the results on mean performance and range of the yield component traits studied in the present investigation are presented in Table 3 .
The character, grains panicle
-1 (228.43) showed the maximum range of variation followed by water uptake (144.58 ml) and plant height (139.40 cm), while minimum range was observed for volume expansion ratio (3.55) (Table 2). Similar findings were reported earlier by
Sharma et al., (2021) and Ravi
Kumar et al., (2015) for grains panicle
-1;
Singh et al., (2020a) for plant height and
Devi et al., (2022) for water uptake. Grain zinc content was ranged from 17.52 to 36.42 with a mean of 27.04 ppm, while iron content ranged from 6.70 to 16.21 with an average of 11.45 ppm. These results are in accordance with the findings of
Jasmine et al., (2022).
Genetic parameters
Variability is very essential for any character for improvement through plant breeding.The genotypic coefficient variation (GCV) phenotypic coefficient variation (PCV), heritability and genetic advance as per cent of mean were computed and analyzed for all characters studied in the present investigation. The results are presented in Table 3.
PCV was noticed to behigher than GCV value for all the traits studied indicating therole of environment. These results are supported by the findings of earlier workers
Sudeepthi et al., (2020), Gunasekaran et al., (2017) and
Kishore et al., (2015). Among the studied traits, productive tillers plant
-1 had exhibited greater difference between phenotypic and genotypic coefficients of variation, compared to other traits, indicating higher influence of environment on the trait, resulting low heritability values for the trait. Moderate GCV and PCV (10-20%) were recorded for grain yield plant
-1, days to 50 per cent flowering, plant height, zinc content, iron content, water uptake and volume expansion ratio. These results are in accordance with the reports of
Sudeepthi et al., (2020) for grain yield plant
-1;
Umarani et al., (2017) for days to 50 per cent flowering;
Jasmine et al., (2022) for plant height, zinc and iron content. In contrast, low PCV and GCV values (<10%) were found for the traits namely, paniclelength, grains panicle
-1, test weight, hulling recovery, milling recovery and head rice recovery indicating low variability for these characters in the present experimental material. Similar findings were reported earlier by
Singh et al., (2020a) for hulling recovery and milling recovery;
Devi et al., (2022) for panicle length and head rice recovery.
In addition, heritability is a good index for the transmission of characters from parents to their offerings. In the present study, estimates of heritability for different characters ranged from 39.29 (productive tillers plant
-1) to 98.64 (grains panicle
-1). High heritability estimates (>60%) along with high genetic advance as percent mean (>20%) would be helpful in predicting genetic gain under selection than heritability estimates alone. In this study, high heritability coupled with high genetic advance as per cent mean was observed for days to 50 per cent flowering, plant height, zinc content, iron content, grain yield plant
-1, water uptake and volume expansion ratio indicating the preponderance of additive gene actionand hence, the effectiveness of simple phenotypic selection for improvement of these traits. These observations are in agreement with the reports of
Devi et al., (2022) and
Lakshmi et al., (2021) for days to 50 per cent flowering, plant height and water uptake;
Sameera et al., (2015) for grain yield plant
-1 and
Jasmine et al., (2022) for zinc content and iron content. High heritability along with moderate genetic advance as per cent of mean was observed for panicle length, grains panicle
-1 and test weight indicating the role of additive and non-additive gene effects for these characters. The results are in accordance with
Perween et al., (2020) and
Tiwari et al. (2020) for test weight;
Sudeepthi et al., (2020) and
Tejaswini et al., (2016) for panicle length.
Character association
The results on character associations between yield, yield components and quality characters are presented in Table 4.
A perusal of these results revealed positive and significant association of grain yield with productive tillers plant
-1, grains panicle
-1, zinc and iron content, indicating scope for simultaneous improvement of these traits. The results are in agreement with the reports of
Singh et al. (2020a) for grains panicle
-1, zinc and iron content and
Ashok et al., (2016) and
Devi et al., (2017) for productive tillers plant
-1.
Further, positive and significant associations were also noticed for days to per cent flowering with productive tillers plant
-1 (Jasmine
et al. 2022), head rice recovery
(Singh et al., 2020a), water uptake
(Ashok et al., 2016); plant height with zinc content, iron contentand hulling recovery
(Singh et al., 2020a); productive tillers plant
-1 with grains panicle
-1, head rice recovery
(Singh et al., 2020a) and water uptake
(Devi et al., 2022), similar to the findings of earlier workers. Grain zinc content had recorded significant positive association with iron content implying the possibility of concurrent selection for both the micronutrients. These results are supported by the findings of
Raza et al. (2019) and
Sing et al., (2020a). Hulling recovery had a significant positive association with milling recovery and head rice recovery similar to the reports of
Singh et al., (2020a).
In contrast, panicle length showed negative and significant associationwith grain yield plant
-1. The results are in conformity with the findings of
Srivastava et al., (2017) for panicle length. Negative and significant associations were also observed for days to 50 per cent flowering with plant height, zinc and iron content
(Singh et al., 2020a); plant height with volume expansion ratio
(Devi et al., 2022); productive tillers plant
-1 with zinc content
(Singh et al., 2020a); panicle length with grains panicle
-1 (Lingaiah et al., 2020) and zinc content
(Jasmine et al., 2022); volume expansion ratio with iron content, similar to the results of earlier workers, indicating the need for balanced selection, while effecting simultaneous improvement of the traits.
Path analysis
The results on path analysis of yield components and quality traits on grain yield plant
-1 are presented in Table 5. A perusal of these results revealed low residual effect of (0.367) indicating that variables studied in the present investigation explained about 63.3 per cent of variability for grain yield plant
-1 and therefore other attributes, besides the characters studied are also contributing for grain yield plant
-1.
A complete analysis of the direct and indirect effects also revealed a high (>0.3) positive direct effectfor head rice recovery, grains panicle
-1 and zinc content. These findings are in conformity with reports of
Shivangi et al., (2019) for head rice recovery;
Singh et al., (2020a) for grains panicle
-1 and zinc content.The traits grains panicle
-1 and zinc content had also recorded high positive and significant association with grain yield plant
-1, indicating the effectiveness of direct selection for these traits in improvement of grain yield plant
-1. Further, the traits productive tillers plant
-1, hulling recovery percent, plant height, days to 50 per cent flowering and water uptake had recorded moderate to low positive direct effects on grain yield palnt
-1. The results are in agreement with the findings of
Jasmine et al., (2022) for number of productive tillers plant
-1;
Singh et al., (2020a) for days to 50 per cent flowering and plant height and
Devi et al., (2022) for hulling recovery and water uptake. Negative direct effects were however; noticed for panicle length, test weight, milling recovery and volume expansion ratio, similar to the results of
Singh et al., (2020a) for panicle length, test weight and milling recovery and
Devi et al., (2020) for volume expansion ratio.
