جستجوی مقالات مرتبط با کلیدواژه "لاین های اینبرد نوترکیب" در نشریات گروه "زراعت"

To investigate the relationships among effective traits on grain yield and determination of and the relationships among them, 137 rice recombinant lines from F6 population along with four control cultivars (Tarom Deilamani, Hashemi, Saleh and Ali Kazmi) were evaluated for nine important agronomic traits and two crop seasons (2015-2016) in a augment design with four blocks. The results of analysis of variance indicated a significant difference among the lines for all evaluated traits. Also, the differences among control varieties were significant for all traits except for leaf length and width. Simple correlation coefficients were calculated for each year separately and showed that 100 seed weight, number of fertile tillers, number of filled grains, panicle length, leaf length and leaf width had a positive correlation with grain yield. Multiple regression analysis by stepwise method was calculated for each year separately and the results showed that for the first year, 100-grain weight and number of filled grain per panicle traits were entered into model, respectively, that explained 62 percent of grain yield variations. For the second year, 100-grain weight, number of filled grain per panicle and number of panicles traits were entered into model, respectively, that explained 73 percent of grain yield variations. Also based on path analysis results, after 100-grain weight (0.926), the number of tiller (0.739) and number of filled grain per panicle (0.682) traits have the most and positive direct effect with grain yield and thus, these traits could be considered as selection criteria for grain yield improvement in rice. The lines include 9, 132, 133, 24, 52, 83, 5, 40, 78 and 19 were selected as elite lines based on the above criteria. Due to the fact that these traits had a great effect on yield, the selected genotypes can effectively be used as high yielding lines for future studies based on these indices.

The development of high yielding cultivars with wide adaptability is the ultimate aim of plant breeders. However, attaining this goal is made more complicated by genotype-environment interactions. The genotype by environment interaction is a major problem in the study of quantitative traits because it complicates the interpretation of genetic experiments and makes predictions difficult, also it reduces grain yield stability in different environments. Multi-environment trials are often analyzed to assess the yield stability of genotypes. Additive main effects and multiplicative interaction (AMMI) model proved to be a powerful tool in diagnosing genotype × environment interaction patterns. The AMMI statistical model has been widely used to explain complicate G×E interaction, to enhance selection efficiency and to ensure genetic gain from selection. The objective of this study was to investigate the response of the lines in studied locations and to identify lines adapted to the test environments.

Order to investigate response of wheat lines to different environmental conditions and determination of yield stability, this study was conducted by 76 recombinant inbred lines derived the cross between Roshan× Superhead based on randomized complete block design with two replications in five environments. The trials were performed at five locations in Kerman, Jopar, Mahan, Yazd and Ardakan. In order to evaluate the interaction and determine the stable lines, the stability analysis was done using AMMI methods. The data were subjected to statistical analysis using SAS and Excel software.

The results of the combined analysis of variance revealed significant differences of grain yield among lines, environment and also line× environment interaction (P<0.01). Since interaction of line × environment was significant, stability analysis was performed using AMMI analysis in order to more accurate evaluate and status of lines stability. The results of Ammi2 bi-plot showed that the least distance from the center of bi-plot with minimum interaction were identified lines 3, 33, 22, 9, 271, 36, 309, 200, 114, 11, 264, 320, 194, 20, 280, 1, 26, 250, 19, 18, 25, 5, 322, 169, 152, 161 and 32 as stable lines. Lines 258, 218, 176, 48, 82 and 314 for Yazd and line 225 for Ardakan indicated the best response and they had private adaptation to these places.

Overall, based on results of this experiment, among evaluated lines, were introduced lines 9, 3 and 22 based on AMMI1, AMMI2 and AMMI stability value (ASV) parameter as general stable lines. Therefore, the identified promising lines can be recommended to complementary studies for introduce to farmers.

To study and determine effect of salinity on relationship between agronomic characteristics and grain yield, 167 of the Seri/Babax recombinant wheat inbred lines (RIL) together with two parents were evaluated using alpha latice design with two replications under two conditions (salt stress and normal), in Zabol field station in 2011-12 cropping season. Fourteen traits including: some agronomic characteristics, grain yield and its components, were measured and recorded for 169 genotypes. Results of simple correlation coefficient analysis indicated a significant positive correlation between grain yield with harvest index, biological yield, the number of spike m-2 and the number of grain m-2 for both normal and stress conditions. Stepwise regression analysis showed that biological yield, harvest index, 1000 grain weight and Days to heading were of higher importance, among other grain yield components for normal condition, in determination of grain yield. Whereas in stress condition, biological yield, harvest index, plant m2 and plant height were the most important. Path analysis coefficients showed that the highest direct effects on grain yield were biological yield and harvest index for both normal and stress conditions. Factor analysis determined four and six factors under normal and salt stress conditions that accounted for 65% and 70% of total observed variations of grain yield. These factors were yield components, quality related traits and grain yield and its components. In conclusion, the results of this study identified harvest index and biological yield as important traits in selection for high yielding wheat genotypes.

The effects some traits on seed yield of recombinant inbred lines of wheat under water deficit stress was studied. This research was done at the Agricultural Research Stations, Islamic Azad University, Tabriz Branch in 2010- 2011. 28 recombinant inbred lines of wheat bread with two parents (Norstar and Zagros) in split plot experiment based on a randomized complete block design with three replications at two irrigation levels (70 and 140 mm evaporation from pan class A) were studied. Analysis of variance indicated a significant genetic differences in all traits under study among the lines. Lines No. 32, 163 and 182 produced highest yield under both irrigation levels. Number of spikes, grains per spike and harvest index had the highest positive correlation with grain yield. Path analysis based on stepwise regression showed that under the normal irrigation conditions, number spike (0.556), number of grains per spike (0.278), weight of 1000 grain (0.259) and the drought stress number spike (0.430), straw yield (0.276) and peduncle length (0.323) had the most direct and positive effect on yield respectively.

In order to determine the relationship between yield and some morphological and physiological traits, as well as important traits that affect grain yield in bread wheat, a field experiment was conducted at Cereal Research Farm, Seed and Plant Improvement Institue, KaraJ in 2007. Three hundred and thirty five bread wheat recombinant inbred lines were evaluated in an Alpha Lattice design with two replications. Grain yield was positively correlated with all of the yield components, but was negatively correlated with days to heading, days to anthesis, days to ripening, extrusion peduncle length and second internode length. In stepwise regression, grain production rate was the first variable entered in the model and explained a higher percentage variation in grain yield. Path analysis showed that grain production rate and biological yield (0.534 & 0.532) exerted the most direct effects on grain yield. On the basis of these result, it is suggested that criteria such as number of spike per m2, number of grain per m2, seed weight per spike, biological yield production rate, grain production rate and biological yield could be considered as effective criteria for selecting towards grain yield improvement in bread wheat.

Response of 8 bread wheat recombinant inbred lines along with their parental cultivars (Roshan and Super Head) to water deficit was evaluatedin a split plot experimentarranged in randomized complete block design (CRBD) with three replications under three irrigation levels (80, 120 and 160 mm evaporation from the pan) at the Agricultural Research Station of Islamic Azad University, Tabriz Branch in 2009. Univariate analysis of variance revealed significant difference among lines with respect to all the traits studied. Significant differences were observed among irrigation levels for grain yield and thousand-grain weight. Line × stress interaction was significant for harvest index and number of fertile and non-fertile tillers. Roshan cultivar produced highest grain yield. In the factor analysis, the first three factors explained 86.95% of total variation. The two first factors were named as growth and grain yield factors, respectively. Cluster analysis, using WARD algorithm, based on all the traits grouped the lines into two cultivars. Grouping was confirmed by discriminate analysis.