Assessment of genetic variability in fodder oats (Avena sativa L.) for yield and quality

Abstract

The current research program, entitled “Assessment of genetic variability in fodder oats (Avena sativa L.) for yield and quality.” involved the study of thirty fodder oat genotypes collected from AICRP Forage Crops and Utilization, Ludhiana Centre under Punjab Agricultural University. This research was conducted in the hill zone at the Regional Agricultural Research Station at Ambalavayal and the plains at the Instructional Farm in College of Agriculture, Vellayani, during Rabi 2022-23. The fodder oat genotypes were evaluated using a Randomized Block Design (RBD) with three replications. The primary objective of this investigation was to assess the genetic variability in fodder oats and develop a selection index for identifying accessions with high yield and nutritional quality. The fodder oat accessions were harvested during the milky stage of grain filling. Quantitative characters like days to first flowering, days to 50% flowering, number of tillers per plant, number of leaves per plant, green fodder yield per plot, dry matter yield per plot, leaf dry weight per plant, stem dry weight per plant, plant height, days to maturity, leaf-stem ratio, ratoon green fodder yield per plot, crude protein content, crude fibre content, total phenolic content, condensed tannin content, total antioxidant content and phytate content were recorded in all accessions. Statistical analyses, such as analysis of variance, genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), heritability, genetic advance, correlation studies, path analysis, cluster analysis and discriminate function analysis were conducted to determine the extent of variation among the existing oat genotypes. The analysis of variance showed significant differences among the studied traits across different genotypes, indicating variability for effective selection. For green fodder yield in the hill zone, the genotypes OL-12, OL-1937, OL-1980, and OL-1963 performed the best with yield ranging from 8.78kg to 8.46kg per plot, while OL-13, OL-1949, and OL-1896 had the lowest yields ranging from 5.75kg to 6.15kg per plot. In case of plains, the highest green fodder yield was observed in JHO-822(3.5kg per plot). Regarding nutritional traits, OL-1931-1 had the highest crude protein content of 16.15 per cent, while OL-1963 had the lowest of 10.97 per cent. Maximum crude fiber content was in OL-1964 (28.02 per cent), and minimum in OL 1952 (15.97 per cent). Total phenolic content was highest in OL-11 and lowest in OL-1963. Condensed tannin content peaked in OL-15, and total antioxidant content was highest in OL 15 and lowest in OL-125. The anti-nutritional character phytate content was lowest in OL-1974 and highest in OL-1976-1. At Instructional Farm, Vellayani, only 12 genotypes managed to reach maturity stage, and their yield was significantly lower ranging from 3.5kg to 2.2kg plot, which was less than 50 per cent compared to the high ranges in Ambalavayal. Among these 12 genotypes, JHO 822 demonstrated superiority in all yield-contributing traits. Genetic variability parameters such as genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), heritability (h2) and Genetic Advance (GA) were studied to find genetic variability present in the genotypes. In the present study, PCV is higher than GCV for all the characters that were recorded, indicating the role of the environment in the expression of these characters. High heritability coupled with high genetic advance was observed for the characters number of tillers per plant, number of leaves per plant, leaf dry weight per plant, stem dry weight per plant, plant height, leaf stem ratio, crude protein content, total phenolic content, condensed tannin content, total antioxidant content and phytate content, which indicates the presence of additive gene action and hence selection based on these characters will be effective for the genetic improvement of the genotypes. The correlation analysis revealed that the trait green fodder yield was correlated positively and significantly with number of tillers, number of leaves, dry matter yield per plot, leaf dry weight, stem dry weight and plant height was correlated negatively and significantly with trait leaf stem ratio. Path analysis divulged that a beneficial positive direct effect on green fodder yield was reported by days to 50% flowering, number of leaves, stem dry weight, leaf dry weight, plant height and days to maturity. While negative direct effect was recorded for days to first flowering, number of tillers, dry matter yield and leaf stem ratio. The residual effect in path analysis (phenotypic) was 0.3644, so about 63% of the total variation in GFY can be explained by the ten characters taken for study. The genetic diversity analysis classified the 30 genotypes into seven clusters following the Euclidean square method, with cluster I being the largest (14 genotypes), followed by clusters II (8 genotypes), IV (3 genotypes), III (2 genotypes), and clusters V, VI, and VII (1 genotype each). The maximum intra-cluster distance was observed in cluster IV, followed by clusters II, I, and III. The highest inter-cluster distance was observed between clusters IV and VII, followed by clusters I and VII. For a successful breeding program, genotypes should be chosen from clusters with the highest degree of divergence. The study found significant genotypic variation for all the examined characteristics. Based upon Selection Index score the genotypes OL-15, JHO-822, and OL-9 exhibited superiority in terms of yield and yield-attributing characteristics, ranking in the top three positions. These superior genotypes can be considered as potential parents for future breeding projects after assessing their combining ability or advanced to further trials for variety development.