پژوهشنامه اصلاح گیاهان زراعی
پیاپی 38 (تابستان 1400)

Salinity stress is one of the most important factors limiting the growth and production of crops. To evaluate salt tolerance of canola genotypes and identification of tolerant genotypes through salinity stress tolerance indexes, a factorial experiment was conducted based on randomized complete block design with three replications at Sari University of Agricultural Sciences and Natural Resources. Factors consisted of 30 rapeseed genotypes and salinity at zero and 12 dS/m sodium chloride sources (NaCl). Based on higher values of tolerance and yield indices in normal and stress conditions, genotypes of Westona, 401Hyola, Ziho, Jef Neuf, Kunto and Alk were considered as tolerant genotypes and genotypes of skaria, Starlight, Lisandra, Burosemjanaja Sarigol, Niro1 and Niro2 were considered as sensitive genotypes. In addition, biplot analysis and cluster analysis confirmed these results. In cluster analysis, genotypes were divided into three groups. The results of this study indicate that the stress tolerance index (STI), the mean productivity (MP) and the geometric mean productivity (GMP), yield index (YI) and average harmonic index (HM) can be effective in selection of tolerant genotypes and the stress tolerance index (STI) is more effective than the other indexes.

Maize (Zea mays L.) is one of the most important food crops worldwide and is widely used as genetic research material for studying various traits. Identification of genetic loci controlling quantitative trait is an important subject in genetics and breeding programs. In the present study, 102 maize inbred lines was evaluated for agro-morphological traits (plant height, plant height until first ear, leaf length, leaf width, leaf surface, leaf area indexear number, chlorophyll content, grain weight per plant, cob’s dry weight, cob’s diameter in first part, cob’s diameter in middle part, cob’s length, plant dry weight, days to tassel emergence, days to first ear emergence, days to second ear emergence) in completely randomized design with six replications. In the molecular experiment, 8 retrotransposon-based molecular markers primers was used for preparing the molecular profile of lines. Eight IRAP and REMAP primer combinations amplified 40 gene loci. Thirty-eight out of 40 loci (95%) showed polymorphism. The PIC values in the studied lines ranged from 0.084 for Ac/Ds to 0.383 for Pangrangja marker. The Nei’s genetic distance between lines prepared from Mashhad and Kermanshah was 0.053, between lines from Karaj and Mashhad was 0.036 and between lines from Kermanshah and Karaj was 0.032. In the analysis of population structure based on molecular markers, 102 studied lines were grouped into two subpopulations (K = 2). In the association analysis of agro-morphological traits based on two GLM and MLM methods, 24 and 12 marker-trait relationships were identified, respectively. In this study, two commons markers; Heartbraker (480) in cob’s diameter in first part and cob’s length and UBC878 × Ruda in ear number and grain weight per plant were identified with both general linear and mixed linear models. This information can be used in selecting individuals during tobacco breeding programs and developing varieties with high yield and performance.

To determine the relationship between some physiological and yield traits under salinity stress conditions and screening quantitative indices of salinity tolerance, 28 sugar beet (Beta vulgaris L.) genotypes derived from the cross between full-sib 8001 with moltigerm male-sterile single cross C2 and male-sterile monogerm 231×261 with two control varieties were tested in a randomized complete block design with three replications under salinity and normal conditions at Miandoab Agricultural and Natural Resources Research Station. Relationships between traits with root and sugar yield were investigated using correlation, regression and path analysis. Under normal conditions, root yield showed positive correlation with pure sugar yield and negative correlation with sugar content and potassium to sodium ratio. Under salinity stress conditions, positive correlation was observed between root yield and sugar yield, pure sugar yield, potassium to sodium ratio and relative water content of leaves and negative correlation with sodium content and molasses sugar. Changes in environmental conditions caused change in the relationship between root yield and some traits. The results of regression and path analysis showed that under normal conditions if root yield was variable, sugar content and white sugar yield traits justified the changes, thus, in path analysis white sugar yield had the most positive and direct effect and sugar content had the most direct and negative effect on root yield. However, when sugar yield was variable, the traits potassium content, the relative amount of water loss, and nitrogen content justified the changes and among these traits, nitrogen content had the most positive direct effect and the other two traits had the most negative direct effect on sugar yield. On the contrary, under saline condition, if root yield was variable, sugar yield, white sugar yield, syrup purity, and sugar content explained the changes and white sugar yield had the most positive direct effect and sugar yield had the most negative direct effect on root yield. But, when sugar yield is variable, pure sugar yield and syrup purity justify the changes and white sugar yield had the most positive direct effect on sugar yield.

Ajowan (Carum copticum L.) is a plant in the umbellifer family Apiaceae. It’s essential containing thymol, parasiman, and alpha-pinene, carvacrol, which has antimicrobial and fungicidal properties. Polyploidy induction, one of the herbal remediation methods, is used to increase the production of secondary metabolites by using mutagenic chemicals. To investigate the effects of polyploidy induction on the population of Sistan Ajowan an experiment was conducted in a completely randomized design with a randomized design using the colchicine factor (0.2, 0.5, 0.75 and 1 g/l) and period Treatment (6, 12 and 18 h). To obtain the best concentration and time duration of colchicine treatment, the tetraploid plants were cultivated with control plants. Some morphological, physiological, and biochemical were studied. Analysis of variance showed that tetraploid induction was significant for plant height, stem diameter, flower number, lateral branch number, root diameter, fresh weight, chlorophyll a and b, carotenoid, peroxidase, catalase, total protein, and flavonoid. The results of this study showed that the best treatment for ploidy induction was obtained at 0.5 g L -1 and duration of 6 h. The number of chromosomes in diploid plants was 2 and in tetraploid plants were 2, so it can be concluded that colchicine is capable of inducing polyploidy in mating plants. . Results showed that tetraploid (treated) plants were physiologically (chlorophyll a, anthocyanin, ascorbate peroxidase, catalase, phenol, and carotenoid) and morphological (lateral branch number, plant height, leaf number, leaf length and width, and fresh weight). And dry) were superior to control plants. This breeding method can also be used for mating plants.

This research was performed to evaluate 124 different soybean genotypes with different maturity type based on augmented design in six blocks with four control cultivars as Telar, Sari, Williams and Sahar at Baye Kola Agricultural Research Station-Mazandaran Agricultural and Natural Resources Research and Education Center. In order to perform the project, each genotype was cultivated on 3 meter line with 60 cm planting space between rows and 3-5 cm space between two seeds. The results of principle component analysis showed that 77.072 % of data variation was expressed according to five components. The results of biplot indicated that the most traits related to yield; its components and phonological properties were located in two regions except protein content which could be used for the studied genotypes breeding. In addition, based on clustering results obtained from the related traits to first and second components, the studied soybean genotypes were grouped in two clusters which the first one included genotypes with early maturity, high oil content and low yield components and protein content, while the second cluster consisted of late maturity group, low oil content, high yield component and high protein content. In total, on the basis of diversity existence accompanied by the research objective, it could be used the studied soybean genotypes in further breeding programs.

To study genotype, environment and genotype × environment interaction effects for seed yield on chickpea, eighteen chickpea genotypes were evaluated in four locations (Khoramabad, Ilam, Gachsaran, and Gonbad) for two cropping seasons (2014-2016). The experiment were conducted using a randomized complete block design with three replications. Combined analysis of variance for seed  yield showed that the main effects of location, year,location ×year , genotype, genotype × year, genotype × location, genotype× year× location interaction effect, were highly significant. Location and year  main effect were the main source of variation that accounted for 86.1% of the total yield variation. Analysis of variance of additive main effects and multiplicative interaction (AMMI) showed that the first two IPCAs were significant and explained 79.3% of the total yield variation. The results of AMMI (ASV) stability values indicated that for seed yield, genotypes 16, 4, 6 and 1 had the lowest value and therefore the highest general stable for all test environments and genotype G10 with a value of 12.89 of the highest were highly adapted to environment (E4). Based on the values of the first two principal components, AMMI stability value (ASV) and genotype stability index (GSI), genotypes G12,G13 and G6 were identified as the most stable medium yielding genotype respectively (1438.9,1266.3 and 1434.2  kg / ha) and the closest genotype to ideal genotype.

Drought stress is one of the most important environmental factors in reducing barley grain yield and despite recent advances in breeding this crop, there is still a need to improve drought tolerant barley cultivars in the country. In the present study, 81 barley lines were studied during the cropping years of 2018-2019 and 2019-2020 in both normal irrigation and drought stress conditions in the tillering stage. Drought stress was applied using evaporation pan in terms of 50 mm evaporation from the pan. Evaluation of drought stress tolerance using different stress tolerance indices while confirming the existence of genetic diversity, showed that lines No. 38, 48 and 67 with high grain yield in both conditions have high drought tolerance. Most indices had a significant correlation with average yield but the highest correlation with yield was related to K1STI, MP and GMP indices under drought stress and YI, WGMI, K2STI and HM indices under normal irrigation conditions. By cluster analysis, the genotypes were divided into four groups. The genotypes in the first group and to some extent in the second group were acceptable in terms of performance in both environmental conditions and stress tolerance indices, while more than half of genotypes were sensitive to drought stress. Finally, the results of principal component analysis were in good agreement with the results of other methods The information of the present study can be used in performance comparison experiments and other future breeding programs.

Tomato (Solanum lycopersicum L.) is one of the most well-known vegetable species in the world, that its cultivation can be threatened by salinity. Salinity is one of the main abiotic challengs that can negatively affect plant growth and physiology. The effect of the Penicillium chrysogenum endophyte fungus on the improvement of quantitative and biochemical traits of tomato plants under salinity stress (treatment of saline well water with different concentrations of (0, 4, 6, and 8 dS / m-1) was investigated in a factorial fully randomized design with three replications at the Hormozgan University greenhouse. The studied traits included plant height; root dry weight; content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids; relative leaf water content; content of proline, soluble sugars, malondialdehyde and hydrogen peroxide. Although, salinity significantly reduced the plant height, root dry weight, chlorophyll a, chlorophyll b, carotenoids and relative leaf water contents, Penicillium chrysogenum could overcome these challenges and reduce the negative effects of salinity. The presence of endophytes against its absence at salinity stress (8 ds/m-1) of 26.66, 30.43, 21.72 and 8.47%, respectively, improved the traits of proline, soluble sugars, malondaldehyde and hydrogen peroxide. Our findings confirmed the high potential of Penicillium chrysogenum to increase plant fitness, especially under salinity conditions. This issue can be used practically to reduce cultivation restrictions in some areas due to the salinity of the water.

All breeding programs and the development of new superior cultivars around the world are based on germplasm genetic diversity. In order to identify the phenotypic diversity and the morphological and agronomical traits relationship among 57 cowpea accessions,  the study was implemented in the field of the National Plant Gene Bank of Iran,in the 2019-20 growing season, The most important phenological, morphological and agronomic traits were recorded. Analysis of variance showed the existence of genetic diversity between the understudied accessions in terms of all quantitative traits except the number of pods per peduncle. The emphasis that it is possible to find out the desired trait among these accessions. Biomass, number of pods per plant, number of seeds per pod, pod length and 100-seed weight had the highest coefficient of variation. The range of phenological traits of day to 50% flowering (43-103) and day to maturity (69-177) showed that these accessions could be categorized as early, medium and late- maturing biotypes. Grain yield and harvest index had a significant negative correlation (P <0.01) with phenological traits. The 100-seed weight and pod length (P <0.01) were determined as traits affecting grain yield. The results of the principal component analysis showed that the three components explain seventy-two percent of the variability between the accessions. Plant height, number and weight of pods per plant, seed number in pod and grain weight per plant had the highest coefficients in the first component and day to flowering, day to maturity and grain yield had the highest coefficients in the second component. A bi-plot drawing of components and grouping genotypes based on  the traits showed that seventeen accessions are noticeable from yield component point of view. Also, seventeen accessions categorized as early-mature accesssins with high grain yield These results in one hand provide useful information about the agronomical traits diversity among local cowpea landraces and on another hand enable the selection of promising genetic resources for use in future breeding programs.

To evaluate maize hybrids response to salinity stress, a factorial experiment was performed with three replications at the Ardabil Agricultural and Natural Resources Research and Education Center during 2020. The first factors were six maize hybrids (SC647, TWC647, SC704, SC705, SC706 and SC715), and the second factors were three levels of salinity stress (0, 100 and 200 mM NaCl). Electrophoretic analyses by using 8% slab polyacrylamide gels indicated that three, two and one isoforms for superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) were observed, respectively, and for each isoform band the “density × area” scores onto gels were evaluated by MCID software as enzymatic activity. The applied salt stress reduced dry weight seedlings, but increased malondialdehyde (MDA), peroxide hydrogen (H2O2), and activity of SOD, POX and CAT isoforms. Significant correlations were observed between seedling dry weight and POX and CAT. The cluster analysis based Ward method was classified maize hybrids in two different groups. TWC647 hybrid with high biomass, high oxidative defense system and low MDA was salt-tolerance. The results indicated that salt-tolerance hybrids, which are associated with enhanced oxidative defense system.

Production of high yielding hybrid cultivars is the main objectives of breeding programs in sunflower. Therefore, the selection of high yielding hybrids is essential in this plant. In this regard, 24 new sunflower hybrids and Golsa cultivar were evaluated in a simple lattice design with two replications in the Gorgan Agricultural Research Station during 2020 cropping season. In this study, the selection index of ideal genotype (SIIG) and factor analysis was used to select new sunflower hybrids and finding interrelationships among them. Based on the SIIG index, the genotypes G5, G10, G2, G12, G3 and G19 with the highest SIIG values (0.747, 0.689, 0.660, 0.641, 0.640 and 0.572, respectively) were the best genotypes. On the other hand, G23, G15, G24, G25 and G18 genotypes with the least amount of SIIG value (0.233, 0.264, 0.277, 0.278 and 0.285, respectively) were the weakest genotypes for most studied traits. The genotypes of G5, G19, G2, G10, G3, G9 and G11 with high SIIG value and higher seed yield that total average were recognized as superior genotypes from the point of yield and other agronomic traits. Therefore, these genotypes can be used for further testing, including adaptation tests in warm wet areas. Also, the results of factor analysis indicated a positive relationship between stem diameters, head diameter and seed number per head with seed yield. Generally, it can be concluded that traits of stem diameter, head diameter and seed number per head could be used as suitable criteria in selecting for increased seed yield in sunflower breeding programs.

In order to understand the response of soybean genotypes to salinity stress, thirty soybean genotypes were evaluated in two separate experiments for normal (control, zero salinity) and salinity treatments (150 mM sodium chloride) in hydroponic culture medium containing hoagland nutrient solution with 3 replications at the greenhouse.The studied traits in this study were leaf area, shoot height, root length, fresh and dry weight of shoot and root, chlorophyll content (SPAD value), salt injury index, sodium and potassium in the shoot and root, the ratio of potassium to sodium of shoot and root, and the ratio of root to shoot Na and K ion translocation. Simple analysis of variance as well as combined analysis of lines and cultivars showed that the studied lines were significantly different from each other in terms of all studied traits at seedling stage, also, the interaction between genotype and environment was significant for most traits, indicating that the responses of cultivars and lines to salinity is different. Most of the studied traits showed a decrease compared to normal under stress conditions, except for salt injury index, sodium and potassium content in shoots, sodium content in roots, and the ratio of root to shoot Na and K ion translocation. Based on the results of statistical parameters among the studied genotypes, the highest coefficient of phenotypic diversity  were related to leaf area under stress (55.3), fresh root weight under stress (45.28), root dry weight under stress (42.26) and salt injury index under stress (37.99). The lowest coefficients of phenotypic diversity were related to root length under normal conditions (11.7) and chlorophyll content under normal conditions (13.3). The stability analysis of studied genotypes showed that cultivars such as Lee, SG13, Vernal, Will, Winchester, Douglas, LYON, Century 84, Strong, L.87-0174 and Crawford are among the lines that can be used as parents in hybrid blocks to improve salinity tolerance of new cultivars.

Zinc (Zn) and Iron (Fe) are important micronutrients in plant growth and their deficiency in plants, especially in cereal crops, is a major nutritional problem in the world. In order to study the effect of foliar application of zinc and iron on the qualitative traits and grain yield of dryland wheat of Aseman cultivar an experiment was conducted at Gonbad Kavous Agricultural Researches Center during 2019-2020. The experimental was carried out as a factorial based on Randomized Complete Block design with 4 replications. Experimental factors included: foliar application of zinc (2g. L-1) and iron (3g. L-1) were at four levels (foliar application of iron and zinc and combined application of zinc and iron and pure water (control)) and foliar spraying time was at three levels (tillering, shoot elongation and seed filling). The measurements included, grain yield, zinc and iron concentration of grain, grain protein content and leaf photosynthetic pigments content. Results showed that foliar application had a significant effect on the studied traits except chlorophyll a/b ratio. Foliar spraying time was also significantly different in grain protein content, iron and zinc concentration of grain, chlorophyll a and carotenoid content. Foliar application treatments (zinc, iron and mixed zinc and iron) had a significant increase in the concentration of grain zinc and iron as well as grain protein and grain yield in comparison with the control treatment. In general, foliar application of zinc and iron, respectively caused an increase zinc concentration (39.85%) and iron concentration (89.43%) of grain in compared to control. The highest (11.45%) and lowest (7.87%) grain protein obtained from mixed consumption of zinc and iron and control respectively. The foliar application mixed of zinc and iron caused an increase in grain yield (42.48%) in compared to the control. Interaction of foliar application × foliar application time showed that the highest amount of grain yield was belonged to simultaneous treatment of zinc and iron in the stages of grain filling and shoot elongation with averages of 8625 and 8600 kg/ha, respectively. It could be concluded that zinc and iron fertilizer applications cause an increase in the concentration of nutrients and grain yield of dry wheat in the climatic conditions of the this region.

One of the most important diseases of sugar beet (Beta vulgaris L.) is Rhizomania or Root madness, which is currently prevalent in all parts of the world. The damage of this disease in susceptible cultivars has been estimated at more than 50% and in some cases up to 100%. Due to the increase in the countrychr('39')s population and the need for sugar, sugar beet crop has a special place among crops. To evaluate genetic parameters, relationships between traits, and grouping of different sugar beet genotypes, 44 sugar beet hybrids in four regions (Hamedan, Kermanshah, Mashhad, and Shiraz) was evaluated in 2019. The experiment was conducted in the form of an incomplete block design (alpha latest) in 6 replications. The results showed that sugar content and root yield with 88.24 and 59.53%, respectively, had the highest and lowest values of broad-sense heritability. In this study, white sugar yield with root yield, sugar content, sugar yield, sugar extraction coefficient, and white sugar content showed a positive and significant phenotypic and genetic correlation, and with root potassium content and molasses sugar had a negative and significant correlation. Based on stepwise regression analysis root potassium, sugar content, and nitrogen content were explained 52% of the white sugar yield variation and identified as the most effective traits in justifying white sugar yield variation. Cluster analysis classified 44 hybrids and 3 controls of sugar beet cultivar into four clusters in four locations. Cluster number four included hybrids No. 20, 43, 31, 23, 25, 24, and 37 and foreign control cultivars Succara and BTS 213, and had the most suitable quantitative and qualitative characteristics. In factor analysis through principal component analysis, two factors were identified that explained 82.52% of the total variance of the data. In this study, root potassium content and sugar content were identified as the most effective traits, and hybrids located in the cluster of four identified as the most suitable hybrid for future breeding programs.

In other to evaluation of drought stress tolerance, 23 lines of red beans with tow cultivars (Yaghout and Ofogh), were studied in lattice design with two replications in both normal irrigation and drought stress at the Khomein Bean station in 2017. Drought stress applied after complete stability of each plant in third trifoliate leaflet stage. Changes of yield and yield components, grain yield in normal irrigation and drought stress and tolerance and susceptibility indices evaluated in the stages accomplished. Analysis of variance showed that a significant difference among lines are both irrigation. Drought stress reduced evaluated properties, significantly. Drought stress resulting in decreased the most of traits, so that maximum effect of drought stress-related traits were number of seeds plant-1 and yield. In normal condition the highest and the lowest grain yield (2541.7 and 841.6 Kg Ha-1, respectively) were observed in KS31338 and KS31352 line, respectively. In stress condition the highest and the lowest grain yield (1934.7 and 602.2 Kg Ha-1, respectively) were obtained in KS31336 and KS31357 line, respectively. Between stress tolerance indices the highest MP, GMP and STI belonged to KS31336 line and the lowest tolerance index and stress susceptibility index (SSI) were observed in KS31352 line respectively. Grain yield under normal irrigation conditions with grain yield under drought stress conditions and stress tolerance indices (TOL, MP, STI and GMP) had significant positive correlation. Based on the geometric mean of production and the susceptibility indexes, principal component analysis and biplot STI and GMP, KS31336, KS31253, KS31148, KS31337 tolerant to drought stress were identified.

The fungal disease, ascochyta blight, caused by Ascochyta rabiei is a major yield-limiting factor of chickpea (Cicer arietinum L.) around the world. A clear understanding of the chickpea defense mechanism against A. rabiei is very important for breeding resistant cultivars and better management of this fungal disease. Induced resistance to a pathogen is one of the ways which plants use against biotic stresses. This study was conducted in 2018 as a two-factor factorial experiment (time-genotype) in a completely randomized design with three replications for each of the selected times and the control plant in the laboratory of the Plant Breeding Department of the Faculty of Agriculture, University of Mohaghegh Ardabili. In this study, AFP-ca, Protein with leucine zipper, Snakin2, and PGIP genes were selected and plant responses to pathogen were studied in two susceptible and resistant genotypes. The experimental system was conducted in a greenhouse, for both inoculated and mock-inoculated plants a control plant with three technical replicates. RNA extractions from FLIP00-40C (resistant) and FLIP03-135C (sensitive) genotypes were performed using RNX-plus kit at 0, 6, 12, 24, 48, 72 and 96 hours post inoculation (hpi) and also for mock-inoculated plants. The expression of these genes after inoculation by Ascochyta rabiei was measured in susceptible and resistant plants via Real-Time PCR. The results showed an increase in the expression level of all genes studied in this research in resistant cultivar compared with susceptible cultivar. Results showed that the candidate gene from the antimicrobial family (AFP-ca) was upregulated in resistant cultivar at early hours after inoculation (6-24 hpi), and also for PGIP from galacturonase-inhibit protein family, the gene was maximally expressed to early hours of inoculation to 48 hpi. In general, it can be concluded that all genes studied in this research contribute to plant-pathogen interactions and all of them may increase the resistance response to Ascochyta blight disease.

Evaluation of genotypes under multiple environments is the prerequisite for the development of stable and superior genotypes for sustainable barley production in different environmental conditions. In order to evaluate the yield stability and determine the portion of different morpho-phonologic traits in the interaction of genotype × environment in promising barley lines, 17 barley promising lines with three checks including Nimrooze/Sahra and Auxin cultivars and WB-94-3 line) were evaluated in two years (2017 – 2019) using RCBD with three replications in five stations of warm zone including Ahvaz, Darab, Zabol, Gonbad and Moghan. Stability analysis was performed using different nonparametric methods. The results of the nonparametric methods were integrated using selction index of ideal genotype (SIIG). The morpho-phonologic data were analyzed by path analysis model which is composed of a main effect and four multiplicative effects. The flowering time (X1), maturity time (X2), plant height (X3), and 1000-kernel weight (X4) were assumed to be sequential characters to justify grain yield productivity (Y) in barley. The results of analysis of variance of grain yield using parametric and non-parametric methods showed that the effect of genotype, environment and genotype × environment interaction was significant at the level of 1% probability. The results showed that based on the nonparametric methods (SIIG index), lines no. G10, G18, G19, G16 and G15 were stable lines and higher than average grain yield. The positive correlation of SIIG with genotypic components of flowering time (V1) and 1000-kernal weight (V4) indicated that the 1000-kernal weight and flowering time are the main contributor towards GE interaction for grain yield in warm zone barley.

In order to evaluate the effect of drought stress on cultivars and advanced lines of autumn wheat that were in the final stages of release as bread wheat varieties in the Research Center of West Azerbaijan Province and to determine their relative tolerance using the selection efficiency of drought resistance indices (SSI, STI, TOl, MP, GMP, HARM,). Two separate experiments in a randomized complete block design with three replications under two conditions of stress and no drought stress in the research farm of Islamic Azad University, Tabriz Branch during the 2016-2017. The results of combined analysis of variance showed that drought stress significantly reduces grain yield. In the absence of drought stress, genotypes 4, 12 and 13 had the highest grain yield, but in drought stress conditions, no significant difference was observed between the studied genotypes in terms of grain yield. The results of correlation analysis between stress tolerance indices and grain yield showed that grain yield under stress (Y s) with STI, HARM and GMP indices have a positive and very significant correlation and these indices can be a good criterion for the drought tolerant lines. Also, the results of principal component analysis showed that these four indicators were the best indicators for identifying stress tolerant cultivars. In fact, these indices distinguished Fernandez Group A genotypes better than other indices. In cluster analysis, the studied genotypes were divided into 3 groups based on all indices of drought tolerance in both non-stress and stress conditions. Genotypes 4, 11 and 12, which were introduced as the most tolerant genotypes in this experiment, along with several other genotypes, were in the second group, and this group had a higher average than the total average in terms of most drought tolerance indices. The percentage of deviation was lower than the average of this group compared to the other two groups and confirmed the results of other methods used in this study. Considering the results of the numerical value of the indices and also their correlation with grain yield in the absence of stress and drought stress, STI, MP, GMP and HARM indices are the best stress tolerance indices and genotypes No. 4, 11 and 12 were identified as the most tolerant genotypes under study.

Path and biplot analysis based on linear and bilinear models, respectively, are of the effective statistical methods for expressing relationships between traits in plant. In order to study of effective traits on seed yield of bitter vetch, 20 ecotypes were evaluated in a randomized block design with three replications during 2017-2018 growing season in the Research Field of Faculty of Agriculture at Vali-e-Asr University of Rafsanjan. The analysis of variance revealed significant differences among the ecotypes for 16 studied traits except plant and root height in maturity stage and one seed pod length suggesting high variation among the ecotypes for the majority of the studied traits. Correlation analysis showed that there were a positive and significant correlation between seed yield and the most of traits except phenological traits including days to 50% flowering and days to maturing start and days to 50% maturing and two morphological traits including root height in maturity stage and two seed pod length. Stepwise regression analysis indicated that thousand kernel weight, number of seed per plant and number of lateral branch entered into model and explained about 65.7 of the total variation. The results obtained from path analysis demonstrated that thousand kernel weight had the most direct effects on seed yield (an increase of 0.657 g in seed yield per 1 g increase in thousand kernel weight). Biplot of first two components divided the successful ecotypes into two groups and identified the most effective traits association with the success of each group.

In order to study of intra-cultivar variation and genetic gain of yield, yield components and fiber quality traits of cotton (cv. Latif) an experiment was conducted for three years (2015-2017) at Hashemabad cotton research station in Gorgan, Iran. Selection was performed by Pedigree- mass method and selected individual plants were grown in single row plot during experimental years. Analysis of data revealed significant difference between the three populations derived from selection during experimental years by the years. The highest coefficient of variation (CV) estimated for yield (23.8), seed weight (10.7), boll weight, lint percentage and fiber strength (8-8.6), respectively, which confirmed intra-cultivar variation. Boll weight, grain weight and lint weight had the highest heritability and genetic advance. Boll number and seed weight have identified as the most effective components and selection index for yield improvement. Correlation values revealed that micronair index positively correlated with lint percentage (r = 0.40 **) and negatively correlated with seed weight, which indicates importance of them as selection criteria for latif cultivar improvement. We conclude the short term improvements may be achieved through indirect selection for yield and lint percentage. Future efforts should be placed in increasing earliness and fiber strength rates.