Genetic variability and association analysis in rice (Oryza sativa L.) germplasm based on biometrical and floral traits

Abstract

The present experiment was carried out to evaluate 150 rice germplasm accessions for biometrical and floral traits to assess the amount of variability and association among them. Eight biometrical and thirteen floral characters were recorded. Analysis of variance showed that there was a significant variation observed for all the characters studied at a 5% probability level. High PCV and GCV was recorded for spikelet sterility percentage (28.78 %, 21.61 %), number of pollen grains per anther (22.25 %, 21.08 %) and pollen load (31.31 %, 31.12 %). High heritability along with high genetic advance was recorded for all biometrical traits except spikelet sterility percentage and six floral traits viz., stigma length, anther length, style length, apical pore, number of pollen grains per anther and pollen load. Single plant yield showed a positive correlation with thousand grain weight. Mean performance of traits studied indicated that, higher yield per plant was observed in Thilainayagam and a high 1000 grain weight in Sembala. The high number of productive tillers per plant was observed in Kodai. Four genotypes, Thooyamalli, IG 23, IG 24 and Vellai chithiraikar were recorded higher panicle length and the least spikelet sterility percentage was observed in IG 7. Hence, the identified germplasm with distinct biometrical and floral characters could be utilized for further hybridization programme.

Development of New Restorer Lines Carrying Some Restoring Fertility Genes with Flowering, Yield and Grains Quality Characteristics in Rice (Oryza sativa L.)

“…High PCV and GCV values and high genetic advances were recorded for these traits, suggesting further improvement of lines for these characteristics for further selection and subsequent use in the breeding program. Similar results were also reported by [ 54 , 55 , 56 , 57 , 58 , 61 , 63 ]. In general, heritability along with genetic advances can be useful in the selection program.…”

“…Analysis of variance showed highly significant differences between all genotypes for all the studied traits ( Table 2 ), which indicates that each genotype is genetically different from the other for yield, its components, floral traits, and grain quality, indicating that there is variability among the studied lines and they would respond positively to selection. The set of genotypes used in the current study indicated that there were statistically significant differences between them among all the traits that were studied, and these results were consistent with the findings of [ 54 , 55 , 56 , 57 , 58 ].…”

“…Moreover, the genetic advance in percentage (expected) of mean was moderate for days to 50% of heading, panicle length, 1000-grain weight (g), and filament length, while low genetic advances in percentage (expected) of mean were observed for spikelet fertility percentage, hulling percentage, and milling percentage. Similar results were observed by [54,55,58,61,63,64].…”

“…Similar results were reported by [ 65 ] for days to 50% heading, plant height, panicle length, number of filled grains per panicle, 1000-grain weight, and [ 66 ] for days to 50% heading, number of filled grains per panicle, 1000-grain weight, and grain yield per plant. See [ 54 , 55 , 58 , 63 ] for anther length, anther breadth, filament length, duration and of floret opening.…”

Genetic variability and relatedness among yield characters in rice landraces and improved varieties

“…Thus, phenotypic selection might be beneficial in the improvement of traits under consideration. Days to maturity recorded the lowest PCV and GCV illustrating that there was meagre variation in these parameters and the results were in concordance with Aswin et al (2021) and Emi et al (2021). Moderate PCV and GCV were noticed for the plant height and length of the panicle similar to the findings of Bhargava et al (2021) and Prasannakumari et al (2020); grain L/B ratio in corroboration with the results of Roy et al (2021) and Aswin et al (2021) and for grain length reported by Priyanka and Gauraha (2020).…”