Analysis of variability, heritability, and genetic advance in seed yield and related traits of orchardgrass (Dactylis glomerata L.) populations

Abstract

Orchardgrass (Dactylis glomerata L.) genotypes from different natural sources in the Eastern Anatolian Region of Turkey were clonally evaluated to study genetic variation and the relationships between seed yield and its components using a randomized complete block design. Results showed very significant genotypic variances among genotypes for all traits, including agronomic (seed, dry matter, and biological yields), morphological (plant height; panicle length; crown diameter; numbers of fertile, sterile, and total stems; and stem intensity), physiological (percent fertile stems, harvest and fertility indexes), and phenological (heading and anthesis dates) traits, as well as genotype × year interaction variances. Genotypic components were the main contributor to phenotypic variation of all traits (except physiologic traits, stem intensity, and number of sterile stems), resulting in high broad-sense heritability (>50%). Agromorphological and physiological traits had greater phenotypic (PCV), genotypic (GCV), and environmental coefficients of variation, while these were lower for phenological traits. After the phenological traits, plant height, crown diameter, and panicle length were the least variable traits, while stem intensity and fertility index were highly variable. Heritability estimates increased as GCV values approached PCV values. Expected genetic gain greatly increased as heritability estimates and PCV both increased, rather than heritability values alone. The first 5 principle components accounted for 84.90% of total variance. All agromorphological traits (except number of sterile stems) and fertile stem percentage were primary sources of variation of the PC1 axis, while harvest and fertility indexes were for PC2. Out of the 4 clusters, genotypes in cluster 4 of higher seed yield were faster in aboveground biomass accumulation. They also had the best agromorphological traits coupled with early maturity. Seed yield greatly increased as aerial biomass increased without any change in harvest index, but there was a significant decrease in fertility index. It was concluded that selection for dry matter yield could result in a simultaneous increase in seed yield.

Assessment of Variability for Nutritional Traits of Burr Medic (Medicago polymorpha L.) Genotypes with Different Phenology

“…The differences between Cluster II and Cluster III for CP, NDF, and ADP were not significant. Therefore, the clustering and variance analysis results indicated that considerable diversity exists due to significant differences for most of the quantitative traits among the accessions, which has great significance to the plant breeder (Seker et al, 2014).…”

“…Researchers have to improve the quality and yield of legumes using advances in plant breeding to increase their contributions to both grazing and ley farming systems. Genotypes developed from populations collected in local areas supply more advantages than introduced standard genotypic materials for breeding studies due to their high adaptation capability (Seker et al, 2014).…”

Estimation of Genetic Components of Cocoa Populations (Theobroma cacao L.) in Seedling Phase

“…Broad sense heritability (h 2 bs ) estimates were high in all characters except root:shoot ratio (Table 5). The broad sense heritability can be classified as high (H > 50%), moderate (20% <H <50%), and low (H <20%) (Seker et al, 2014). The contribution proportion shows how much contribution of female parents, male parents, and their interactions for each character (Istipliler et al, 2015).…”

Parâmetros genéticos e associação de metodologias de EUN no milho sob diferentes doses de nitrogênio

“…20 relatam que quando a correlação (fenotípica/genotípica) é positiva os mesmos efeitos encontrados num atributo são observados no outro, ou ainda, quando se tem um atributo e dois ambientes. De acordo com Weber et al, 18 a seleção indireta é possível quando existe alta correlação genética entre os ambientes e alta herdabilidade do atributo desejado num dos ambientes.…”