GENETIC VARIATION, CORRELATION AND SELECTION INDICES IN ADVANCED BREEDING LINES OF RICE (Oryza sativa L.)

Abstract

Forty advanced breeding lines of rice were studied during T Aman season (rainfed ecosystem) for finding out selection indices, variability and character association for grain yield and its components. All the tested characters were found showing significant variation. The highest genotypic, environmental and phenotypic variances were found in filled grains/panicle followed by plant height. High heritability associated with high genetic advance were obtained in panicles/hill, plant height, filled grains/panicle, 1000-grain weight and grain yield. Genotypic correlation coefficients were higher than the corresponding phenotypic correlation coefficients in most of the cases. Panicle length, panicles/hill and filled grains/panicle showed significant positive correlation with grain yield. Path analysis revealed that filled grains/panicle, panicles/hill and 1000-grain weight had positive and highest direct effects on grain yield. Moreover, panicle length had highest indirect effect on grain yield through filled grains/panicle. Discriminant function analysis revealed that a progressive increase in the efficiency of selection was observed with the inclusion of additional character in the selection index. Among the single variable indices, filled grains/panicle showed maximum relative efficiency over the straight selection for grain yield. The highest relative efficiency was observed with index involving seven characters, days to maturity + panicle length + panicles/hill + plant height + filled grains/panicle + 1000-grain weight + yield (t/ha). However, some of 3-traits, 4-traits, 5-traits, and 6-traits indices were also equally good.

Construction of some selection procedures for improvement of grain yield in durum wheat

“…These results indicated the feasibility of selection for these traits. Our results are in accordance with those obtained by Habib et al (2007), Ferdous et al (2010), Fellahi et al (2018), and Rasha (2020. The reduction in PCV and GCV values in the advanced generation (F3, F4, and F5) may be due to a reduction in genetic variability and heterozygosity as a result of using different selection procedures that exhausted a major part of variability.…”

“…When single trait selection is practiced and the correlation of that trait with others is high and unfavorable, an undesirable correlated response may occur for those traits not considered in selection criteria (Bos and Caligari, 1995;Patel et al, 2019). In order to get through these obstacles in a multi-trait approach, breeders are concentrating on additional traits that can be employed concurrently with or independently of yield (Habib et al, 2007). A breeding program's likelihood of success is increased by simultaneously selecting features that are important from an economic perspective (Sayd et al, 2019).…”

Simultaneous Selection of Sweet-Waxy Corn Ideotypes Appealing to Hybrid Seed Producers, Growers, and Consumers in Thailand

“…Variance components and genetic gains are routinely estimated to evaluate the effectiveness of the selection method applied to certain breeding objectives [48]. Previous studies reported larger genetic gains from simultaneous selection than single-trait selection in several crops such as rice [49], sugarcane [50], wheat [51], and maize [26]. In our study, the realized gain of both ORSI and selection index was assumed as the percent average differences between selected means and grand means.…”

Genotypic potentiality and selection index of ridge gourd (Luffa acutangula L.)

“…Selection index is commonly used in grain crop for selecting efficient combination characters and improvement of crop based on that combination index. Selection index was reported by Yang et al (1991) in wheat, Habib et al (2007) in rice and Bashar et al (2015) in egg plant.…”