Genetic parameters and diversity studies of yield and yield contributing characters in Brassica genotypes

Abstract

The potential of a crop to favorably respond to breeding programs depends on its existing nature and magnitude of genetic variability, heritability and genetic advance. An experiment was conducted with eighteen Brassica genotypes following Randomized complete block design (RCBD) with three replications at the field of the department of Genetics and Plant Breeding, Bangladesh Agricultural University, Mymensingh, Bangladesh to estimate genetic divergence, variability ranges and contribution of each trait towards genetic diversity. Analysis of variance showed significant variation among the genotypes for all the studied yield and yield contributing characters. The phenotypic co-efficient of variation (PCV) was higher than the genotypic co-efficient of variation (GCV) for all the characters measured, indicated that the traits were influenced by environment. All traits showed high heritability (61.54% to 98.64%) which indicated possible improvement through selection. High heritability values (>60%) along with high genetic advance and genetic advance in percentage of mean indicated prevalence of additive gene action, which provides good scope for further improvement by selection. The genotypes were grouped into four clusters, most of the genotypes were grouped into Custer I (8 genotypes), while cluster IV contained only one genotype. Considering the mean value, the cluster IV and Cluster II were ranked as the top groups in terms of yield and early maturity. High Heritability with high genetic advance in percentage of mean was observed for number of branches/plant, number of pod/plant, number of seeds/pod and yield/plant and selection focused on these traits could be useful for future breeding program of Brassica. The genotype BD-7114 was the best performer considering all the studied traits especially yield and days to maturity which could be used as an important breeding material for the improvement of Brassica.
 J Bangladesh Agril Univ 17(3): 295–300, 2019

Variability and heritability study in some selected Brassica rapa L. genotypes

“…Higher value of PCV (30.23%) and GCV (29.52%) had also estimated for this trait indicated the existence of inherent variability among the studied genotypes but differences between phenotypic and genotypic variance was relatively higher (124.21) indicated influence of environment (Table 3). The result matched with Aktar et al, (2019), Gupta et al, (2019) and Rout et al, (2019). The genotypic variance (34.42), phenotypic variance (33.52), environmental variance (0.90), high GCV (26.76) and high PCV (27.12) had estimated for number of seeds siliqua -1 (Table 3).…”

“…The PCV and GCV also had the higher values, 25.38 and 25.19 % respectively (Table 3). Iqbal et al, (2015), Naznin et al, (2015) and Aktar et al, (2019) also found the similar results. High PCV and GCV values for this traits had supported by Gupta et al, (2019), indicated the existence of inherent variability among the studied genotypes for this trait.…”

“…Very low environmental influences and high GCV, PCV indicated presence of additive gene effects and hence the selection might be effective for this trait. Sikarwar et al, (2017), Aktar et al, (2019) and Rout et al, (2019) also estimated similar result for this trait. The genotypic and phenotypic variance for siliqua length was 0.297 and 0.292 respectively with environmental variance 0.005 (Table 3).…”

“…High heritability and high genetic advance and gain indicating that this trait was under additive gene control and selection for genetic improvement for these traits would be effective. Sikarwar et al, (2017), Salam et al, (2017), Singh et al, (2018), Aktar et al, (2019) and Gupta et al, (2019) also observed similar result. High heritability (98.55%) coupled with high genetic advance (53.99 %) and genetic gain (51.53 %) had estimated for this trait (Fig.…”

“…Low environmental influences focused on additive gene effects. Aktar et al (2019) and Rout et al, 2019; also reported less environmental influences for these traits.…”