جستجوی مقالات مرتبط با کلیدواژه « gge biplot » در نشریات گروه « بیوتکنولوژی و ژنتیک گیاهی »

Identifying selection indices is the most important step of a breeding project that aims to improve grain yield. The definition of the selection index is usually done by evaluating the variables in multivariate statistical methods. In the present study, the relationship between grain yield and its components in bread wheat genotypes was determined by multivariate statistical methods. The experiment was conducted in a randomized complete block design with 3 replications in the research farm of Gorgan University of Agricultural Sciences and Natural Resources in the 2018-19 crop years. Ten commercial cultivars of bread wheat along with their offspring from direct and inverse crosses in a dialysis arrangement were evaluated for morphological and phenological traits, especially grain yield and its components. The results of genotypic and phenotypic correlation coefficients showed a positive and significant correlation (at 1% probability level) between grain yield and spike length, spike weight, number of fertile tillers, number of seeds per spike, number of spikes per spike, 1000-seed weight, biological yield and harvest index. Based on the results of stepwise regression analysis, biological yield, harvest index, number of grains per main spike and main spike weight were entered into the regression model, respectively, and explained a total of 98% of the variation in grain yield. Based on the results of path analysis, biological yield had the highest direct effect on grain yield. After biological yield, the most direct effect on grain yield was related to the weight of main spike. Also, by considering eigenvalues greater than one in factor analysis, 8 hidden factors were identified that explained a total of 75.18% of the data changes. In general, it can be concluded that biological yield, harvest index, number of seeds per spike and weight of spike compared to other traits can be used as appropriate indicators in breeding programs to select high-yield genotypes in field conditions. Genotypes Alo, Ehsan♂ × Gonbad♀ and Ehsan had the highest value for the studied traits, which can be used in future breeding researches.

To determine essential oil yield stability in different populations of thyme (Thymus kotschyanus), 20 plant populations were examined in normal conditions at 11 stations, consisted Damavand, Esfahan, Golestan, Hamedan, Khorasan, Markazi, Qom, Tabriz, Tehran, Yazd and Zanjan. Data were analyzed in split plot in location design. Based on combined analysis of variance, genotype × location interaction was significant at (p>1%). This showed differences of the studied populations in yield and response to different conditions in eleven locations. In Graphical analysis, 11 environments were divided into 3 Mega environments. In mega environments Khorasan, Qom, Markazi, Damavand, Yazd, Zanjan and Tehran, genotypes 5, 27, 51 and 54 showed special compatibility. Genotypes 3 and 17 in Tabriz and Hamadan mega environment and genotypes 10, 8, 70 and 50 in mega environment of Golestan showed special compatibility. Assessment based on essential oil yield and stability of genotypes showed that accessions 5, 54 and 29 were suitable accessions. Graphical analysis of relationships between the environments, Khorasan, Qom, Markazi and Damavand, formed a group environment. Khorasan, Tabriz, Isfahan and Golestan locations showed significant role in differentiation of the studied genotypes. Based on graphical analysis of relationship between the genotypes, genotypes of 54 (Naghade), 27 (unknown 1), 51 (Tehran), 56 (Zarand) and 5 (Qazvin 2) formed a high production group presenting special compatibility to mega environment of Khorasan, Qom, Markazi, Damavand, Yazd, Zanjan and Tehran. The mentioned genotypes could be used for thyme cultivation in the mentioned areas.

This study was conducted to determine grain yield stability of rainfed promising barley genotypes in six Iranian rainfed research stations (Maragheh، Sararood، Uromieh، Ghamloo، Zanjan and Ardabil) under cold and semi-cold conditions during three cropping seasons (2006-2009). The studied genotypes were 10 promising barley lines along with two checks (one local variety and newly released variety of Abidar). In each environment، the experiment was arranged in randomized complete block design (RCBD) with four replications. Results of combined ANOVA showed that location، year، genotype، interaction oflocation and genotype، and interaction of year، location and genotype had significant effect on grain yield. The genotypes showed the highest and the lowest grain yield in Sararood (2549 Kg/ha) and Zanjan (1578 Kg/ha) stations، respectively. Line No. 9 produced the highest grain yield (2061 Kg/ha). To study the interaction of genotype and environment، GGE biplot method was used. Based on the polygonal graphs related to genotypes، genotype No. 1 (G1) produced the highest yield in Ardabil and genotype No. 5 (G5) showed the highest yield in Zanjan، Maragheh and Uromieh. Besides، genotype 3 (G3) and genotype 4 (G4) produced the highest yield in Ghamloo and Sararood stations، respectively. Based on the theoretical ideal environments graph، Uromieh was closer to the ideal environment. Regarding to the imaginary ideal genotype graph and biplot of genotypes and environments، genotype No. 5 was identified as the best one due to its higher yield and better yield stability.