Diallel analysis of oil content and some agronomic traits in rapeseed 50

Abstract Development of high oil content varieties is one of the most important aims of current rapeseed breeding programs. A set of 36 diallel F1 hybrids, their parents and four additional cultivars were evaluated in the breeding nurseries during 2008 and 2009. Plant height (PH), number of lateral branches per pod (NBP), main stem length, number of grains per pod, days to start of flowering (DSF), 1000 grain weight (GW), harvest index (HI), and oil content (OC) were measured. Diallel analysis was carried out considering the additivedominance genetic model to estimate variance and covariance components. The additive genetic variance component was significant for NBP and DSF, the dominanace genetic variance for PH and the additive by year interaction for PH and OC. GW However, dominance by year interaction was significant for all characters under investigation and played a major role in the inheritance of these traits. This implies that the utilization of heterosis could be effective for the genetic improvement of oil content and agronomic traits in rapeseed in specific environments. Positive dominance effects of oil content were seen in Okapi × Orient and SLM046 × Opera crosses followed by SLM046 × Colvert and Fornax × Okapi combinations. Fornax, Talaye and Modena proved good general combiners and could be used for the improvement of oil content and agronomic characters. NBP, NGP and HI had significant effects on the oil content. These characters should be given more attention as the main traits of selection for the purpose of improving oil content in rapeseed

Grouping bread wheat genotypes and lines based on some morphological traits using multivariate analysis

The knowledge about the extent of variability among bread wheat (Triticum aestivum L.) genotypes is a high value for the genetic improvement programs and the efficient genetic diversity utilization of plant materials. The objective of this research was to assess the morphological characteristics of 56 common wheat genotypes which were planted under field condition and their morphological traits were recorded. The principal components (PC) analysis, factor analysis and clustering procedure were applied to group genotypes according to similarity on the basis of the measured traits. Results showed that the first two PCs explain 41% of the total variation. The PC and factor analyses grouped genotypes into four groups while the cluster analysis grouped them into five distinct clusters. The cluster I had good resistance to yellow rust and salinity while the cluster II, had good resistance to drought, cold and salinity. The cluster III had high tolerance to cold stress and low temperatures but the cluster IV had good tolerance to drought, brown rust and yellow rust. Also, cluster V had various properties including tolerance abiotic stresses, resistance to biotic stresses, resistant to lodging and semi-dwarf property. The results of this research will support efforts of conservation and utilization of genotypes in bread wheat breeding programs

Genotype × environment interaction for grain yield of some lentil genotypes and relationship among univariate stability statistics

Lentil (Lens culinaris Medik.) is traditionally grown as a rain fed crop, particularly in the Middle East; its seed is a rich source of protein for human consumption in developing countries such as Iran and others. The stability of 11 different lentil genotypes was investigated using 19 univariate stability parameters. Field experiments were conducted in 20 rain-fed environments in Iran’s lentil producing areas to characterize genotype by environment (GE) interactions on seed yield of 11 lentil genotypes. Combined analysis of variance across environments indicated that both environment and GE interactions significantly influenced genotype yield. Several statistical methods and techniques were used to describe the GE interaction and to define stable genotypes in relation to their yield. The results of these different stability methods were variable. However, most showed genotype FLIP 92-12L was stable and genotype Gachsaran was unstable. Genotypes identified as superior differed significantly from local cultivars and can be recommended for use by farmers in semi-arid areas of Iran. Principal component analysis was used to obtain an understanding of relationships among stability techniques. It showed the parameters studied could be grouped in five distinct classes. Clustering of the genotypes indicated that there were two genotypic groups in this group of genotypes

Mediciones no paramétricas corregidas y sin corregir en ensayos multiambientales de estabilidad con trigo duro

This study was done to evaluate yield stability of 20 improved durum wheat genotypes (G1 to G20). Tests were done in a randomized complete block design with 4 replications for 3 years at 5 sites in multi-environment trials. Data were analyzed with the five nonparametric stability measurements of Thennarasu (NP) according to ranks of corrected and uncorrected procedures. Results for the combined analysis of variance for environment (E), genotype (G) and GE interaction was significant, suggesting different responses of the various genotypes in the study and the requirement of yield stability analysis. In this study, low values determined by uncorrected NPs (UNP2, UNP3, and UNP4) were associated with high mean yield, but other nonparametric stability measurements were not positively correlated with mean yield and were thus characterized as having a static concept of stability. Although, according to both corrected and uncorrected stability parameters, genotypes G7, G8, G13 and G14 were stable but only G7 flowing to G8 had high mean yields. Results of the factor analysis, Spearman's rank correlation and the bootstrap resampling procedure of the nonparametric stability measurements and mean yield indicated that using ranks of uncorrected data would be useful for simultaneous selection for both mean high yield and stability. In conclusion, according to results of these different nonparametric stability measurements, genotype G7 is recommended for commercial release as a favorable durum wheat genotype for the environmental conditions in Iran.Se estudió la estabilidad del rendimiento de 20 genotipos mejorados (G1-G20) de trigo duro en un diseño en bloques completos al azar con 4 repeticiones de 3 años en 5 ambientes diferentes. Los datos fueron analizados con las cinco medidas de estabilidad no paramétricas de Thennarasu (NP), de acuerdo a los rangos de los procedimientos corregidos y sin corregir. El análisis de varianza combinado para los ambientes (E), los genotipos (G) y la interacción GE fue significativo, lo que sugiere una respuesta diferencial de los genotipos y la necesidad de analizar el rendimiento de la estabilidad. En este estudio, se asociaron valores bajos de NP no corregidos (UNP2, UNP3 y UNP4) con un elevado rendimiento medio, pero las otras medidas no paramétricas de estabilidad no se correlacionaron positivamente con el rendimiento medio y se consideraron como concepto estático de estabilidad. Sin embargo, de acuerdo con los parámetros de estabilidad, tanto corregidos como sin corregir, los genotipos G7, G8, G13 y G14 se mantuvieron estables, pero solamente G7 y G8 tuvieron un elevado rendimiento medio. Los resultados del análisis factorial, de la correlación de Spearman y del procedimiento bootstrap de nuevo muestreo de las mediciones de estabilidad no paramétricas y la media de rendimiento, indicaron que sería útil utilizar datos incorrectos no corregidos para seleccionar de forma simultánea elevados rendimientos y estabilidad. En conclusión, de acuerdo con los resultados de las diferentes mediciones de estabilidad no paramétricas, se recomienda el genotipo G7 de trigo duro para su uso comercial como el más favorable en Irán

Interrelación entre el rendimiento de las semillas y veinte caracteres asociados de 49 cultivares de colza (Brassica napus L.) en entornos sin estrés y con estrés hídrico

Development of new canola (Brassica napus L.) cultivars requires efficient tools to monitor trait association in a breeding program. The efficiency of a breeding program depends mainly on the direction of the correlation between yield and its components and the relative importance of each component involved in contributing to seed yield. This research uses sequential path analysis to determine the interrelationships among seed yield and 20 related traits. Forty nine canola genotypes were grown in two environments (non-stressed and water-stressed conditions) to determine the important components of seed yield. Observations were recorded on 20 other canola traits. Correlation coefficient analysis revealed seed yield was positively correlated with all the traits except stem diameter and days to flowering in the non-stressed environment. Seed yield was significantly positively correlated with all measured traits except first pod height, first lateral branch height, number of lateral branches pod-1, number of pods plant-1 and stem diameter in the water-stressed environment. Sequential path analysis identified the 1000-seed weight (TSW) and main stem length as important first order traits that influenced seed yield in the non-stressed environment. Plant height and the TSW were important first order traits that influenced seed yield in the water-stressed environment. All direct effects were significant, as indicated by bootstrap analysis. The results suggest that TSW could be used as a selection criterion in selecting for increased seed yield in canola in both non-stressed and water-stressed conditions.En los programas de mejora, el desarrollo de nuevos cultivares de colza (Brassica napus L.) requiere herramientas eficaces para analizar la correlación entre el rendimiento de las semillas y sus componentes genéticos. La presente investigación utiliza un análisis secuencial para determinar las interrelaciones entre el rendimiento de las semillas y 20 caracteres relacionados. Se cultivaron 49 genotipos de colza en dos ambientes (sin estrés y con estrés hídrico) para determinar los componentes más importantes del rendimiento de las semillas y se realizaron observaciones sobre otros 20 caracteres. El análisis del coeficiente de correlación reveló que el rendimiento de las semillas está positivamente correlacionado con todos estos caracteres, excepto con el diámetro del tallo y días hasta la floración en condiciones sin estrés, y con la altura de la primera vaina, altura de la primera rama lateral, número de ramas laterales por vaina, número de vainas por planta y diámetro del tallo, en condiciones de estrés hídrico. Del análisis secuencial se dedujo que el peso de 1000 semillas (TSW) y la longitud de tallo principal son los caracteres que más influyen sobre el rendimiento de las semillas en condiciones sin estrés hídrico, y la altura de la planta y el TSW en condiciones de estrés hídrico. En un análisis bootstrap, todos los efectos directos fueron significativos. El estudio sugiere que podría  utilizarse el carácter TSW en la selección para aumentar el rendimiento de semillas de colza, tanto en condiciones sin estrés como con estrés hídrico

Genotype x environment interaction for grain yield of some lentil genotypes and relationship among univariate stability statistics

Lentil (Lens culinaris Medik.) is traditionally grown as a rain fed crop, particularly in the Middle East; its seed is a rich source of protein for human consumption in developing countries such as Iran and others. The stability of 11 different lentil genotypes was investigated using 19 univariate stability parameters. Field experiments were conducted in 20 rain-fed environments in Iran�s lentil producing areas to characterize genotype by environment (GE) interactions on seed yield of 11 lentil genotypes. Combined analysis of variance across environments indicated that both environment and GE interactions significantly influenced genotype yield. Several statistical methods and techniques were used to describe the GE interaction and to define stable genotypes in relation to their yield. The results of these different stability methods were variable. However, most showed genotype FLIP 92-12L was stable and genotype Gachsaran was unstable. Genotypes identified as superior differed significantly from local cultivars and can be recommended for use by farmers in semi-arid areas of Iran. Principal component analysis was used to obtain an understanding of relationships among stability techniques. It showed the parameters studied could be grouped in five distinct classes. Clustering of the genotypes indicated that there were two genotypic groups in this group of genotypes.La lenteja (Lens culinaris Medik.) se cultiva tradicionalmente en regadío, particularmente en el Oriente Medio, y su semilla es una fuente rica de proteínas para consumo humano en países en desarrollo como Irán y otros muchos. Se investigó la estabilidad de 11 diferentes genotipos de lenteja utilizando 19 parámetros univariados. Para caracterizar la interacción genotipo × ambiente (GE) de la producción de grano de 11 genotipos de lenteja, se realizaron experimentos de campo en 20 ambientes de regadío de las áreas productoras de Irán. Análisis combinados de varianza entre ambientes indicaron que tanto los ambientes como las interacciones GE influyeron significativamente en la producción de los genotipos. Se utilizaron varios métodos estadísticos para describir la interacción GE y definir los genotipos estables respecto a la producción. Los resultados de los diferentes métodos fueron variables, pero la mayoría mostraron que el genotipo FLIP 92-12L es estable y que Gachsaran es inestable. Los genotipos calificados como superiores difirieron significativamente de los cultivares locales y pueden ser recomendados para ser utilizados por los agricultores de las zonas semi-áridas de Irán. Se utilizó un análisis de componentes principales para analizar las relaciones entre las técnicas de estabilidad. El análisis mostró que los parámetros estudiados pueden ser agrupados en cinco clases, y los genotipos pueden agruparse en dos grupos

Study of Diversity and Evaluation of Relationships Between Yield and Yield Components of Rapeseed via Multivariate Methods

Using multivariate statistical methods in evaluation of various traits in several genotypes has caused the discovery of different aspects of agronomic crops’ traits. In order to study diversity and interrelationships of yield and yield components of rapeseed, 36 genotypes of rapeseed were used in a 6 × 6 simple lattice design layout with two replications. Results of primary analysis of variance indicated that it was possible to analyze the dataset via randomized complete blocks design. In general, 13 traits, which were related to yield and yield components, were evaluated in this investigation. Results of dataset analysis showed that there was considerable variation among the genotypes. Seed yield of rapeseed had positive and significant correlation with 1000-seed weight, harvest index, number of secondary branches in plant and maturity period. In stepwise regression of yield with other traits, the 1000-seed weight and days to end of flowering described most of the variations of seed yield. Also, results of path analysis indicated that 1000-seed weight and days to end of flowering had direct and remarkable effect on seed yield. Cluster analysis and multivariate analysis of variance divided the genotypes into five distinct groups. Based on seed yield and 1000-seed weight, the genotypes of fifth cluster and according to highest number of pods per plant, the genotypes of third cluster were considerable. In general, the most important trait which affected seed yield of rapeseed was 1000-seed weight, which could be used for indirect selection of seed yield in segregating generations