جستجوی مقالات مرتبط با کلیدواژه « شاخص MGIDI » در نشریات گروه « زراعت »

Wheat, as one of the most important crop on earth, is the main supplier of human food. This research was conducted to investigate the wheat recombinant inbred lines based on the germination components and compare them with the control varieties of the region to select the best lines using the selection index of the multi-trait genotype-ideotype distance (MGIDI). For this purpose, 40 wheat inbred lines (F8) were evaluated along with six control varieties (Arman, Araz, Ehsan, Tirgan, Meraj and Kalateh). According to the results of the analysis of variance, a significant difference between the studied lines was observed for all traits (P<.01). The results of factor analysis for the studied traits identified three factors that explained 86.93% of the total variation. Based on the MGIDI index, seven lines L3-4, L7-5, L7-4, L8-5, L4-4, L5-3, and L3-3 were selected as the superior genotypes with the lowest distance to the ideal genotype. Based on the cluster analysis, the genotypes were divided into five groups, and the genotypes of the fifth group were identified as the best genotypes in terms of all germination components and seedling traits, and were consistent with the genotypes identified based on the MGIDI index. The highest percentage of differential selection and genetic gain was assigned to the fresh weight vigour index (49.16% and 29.14%, respectively), which shows that the superiority of the selected genotypes is more prominent in terms of this trait. Based on the results, the recombinant inbred lines were significantly superior to the control cultivars in terms of the studied traits. Also, the results of this study showed that the use of the MGIDI index can efficiently identify superior genotypes.

Identifying genotypes that combine high performance across many traits has been a challenger task. Classical linear multi-trait selection indexes are available, but the presence of multicollinearity and the arbitrary choosing of weighting coefficients may erode the genetic gains. Therefore it is necessary use novel approach for elite genotype selection based on multiple traits that overcome the fragility of classical linear indexes. The aim of this study was initially to select superior genotypes based on grain yield and a number of morpho-phenological traits and finally to compare different indicators for selecting ideal genotypes.

In order to evaluate a number of pure barley lines using multi-trait selection indicators in the Darab Agricultural Research Station, two one-year experiments in the crop years (2017-19) and one two-year experiment (2019-2021) were done. The first year experiment consisted of 108 pure barley lines which were executed as an Augment design and in the second year 34 lines were selected for Darab region. The selected lines were performed using two separate 1 and 2 experiments in a randomized complete block design with three replications. Then, 11 promising lines were selected and along with 6 other lines that were top in Zabul and Moghan regions, were examined in a two-year experiment. The two-year experiment was performed using a randomized complete block design with three replications.

The results of variance analysis of two-year experiments showed that the effect of year was significant for all traits except plant height. The effect of genotype was significant for all traits except grain yield and on the other hand, the genotype × year interaction was significant only for grain yield at 5% probability level. The Smith-Hazel index selected three genotypes, G7, G2 and G15, as the superior genotypes. In the multi-trait genotype-ideotype distance index (MGIDI), genotypes G15, G2, G16 and G20 were selected as the best genotypes. G14, G8 and G18 genotypes were among the top genotypes using factor analysis and ideotype design via best linear unbiased prediction index (FAI-BLUP). According to the results of selection index of ideal genotype (SIIG), G20, G17, G19 and G15 genotypes were the top genotypes with the highest SIIG values, respectively. The results of correlation between the studied traits and MGIDI, FAI-BLUP and SIIG indices showed that all indices except FAI-BLUP had a significant correlation with grain yield. Among the indicators, FAI-BLUP did not show a significant correlation with any of the indicators.

In general, the results of different indices showed that in the conditions of this study, none of the indices showed superiority over each other, and therefore finally the G15 genotype, which was the ideal genotype based on most indices, and the genotype G14 (selected genotype by FAI-BLUP index) due to its earlier maturity and high grain yield as the best genotypes in this study for cultivation and introduction in the southern regions of the country that have a similar climate to Darab, is recommended.

The cow cockle has a great potential for producing medicinal products due to its triterpenoid saponins. This experiment was aimed to investigate different cow cockle ecotypes under drought stress conditions and select the tolerant ecotype(s) based on agronomic traits using selection indices under different irrigation regimes.

This experiment was carried out as a split-plot experiment based on a randomized complete block design with three replications in 2020-2021 at the Ghezel Moghan Seed Production Company in Parsabad. The main plots were assigned to three treatments of irrigation cycle of 7 days (no stress), 10 days (mild stress), and 14 days (severe stress), and sub-plots were allocated to eight cow cockle ecotypes native to the northwest of Iran.

The analysis of variance showed the effect of drought stress on all studied traits and the effect of ecotype on all traits except for seed weight per plant was significant. Also, their interaction effect was significant in most of the studied traits such as plant height, number of branches, seed weight per plant, number of filled and hollow capsules, straw weight, grain yield, biological yield, and harvest index and was nonsignificant for the percentage of full capsules, plant biomass, and 1000-grain weight. Ecotype E7 under normal conditions had the highest plant height, number of branches, number of full capsules, and seed weight per plant, but in severe stress conditions, it showed the lowest height, number of branches, number of full capsules, seed weight per plant, 1000-seed weight, straw and seed yield per unit area and was the most sensitive ecotype to drought stress. Ecotype E6 had the least decrease in plant height, number of branches, seed weight per plant, straw and seed yield per unit area, and harvest index in both stress conditions and was the most tolerant to drought stress. Estimation of the ideal genotype selection index (SIIG) and Multi-trait genotype–ideotype distance index (MGIDI) for different ecotypes showed that the E6 ecotype with the highest SIIG value and the lowest MGIDI value in all three stress conditions was the most tolerant, and E3 and E8 ecotypes were in the next rank and were classified as ecotypes with relatively high drought tolerance. Also, in both moderate and severe stress conditions, ecotype E7 with the lowest value of SIIG and the highest value of MGIDI showed high sensitivity to drought stress.

In general, the E6 ecotype was desirable in both normal and stress conditions and was one of the ecotypes with high drought tolerance. Also, in both moderate and severe stress conditions, Eotype E7 showed high sensitivity to drought stress