Seed and Plant
Year:2005 | Volume:21 | Issue:1|Papers Count:13

In order to study the adaptability and yield stability of dryland promising durum wheat genotypes, this experiment was conducted with 22 genotypes of durum wheat plus 2 bread wheat cultivars as checks in RCBD for three cropping seasons (1998- 2001) in six cold research stations in dry land areas. In each location simple ANOV A and combined ANOV A for three years were implemented. Because in combined" analysis (3 years in each location) and according to Hartly Fmax test, the error mean squares (MSe) at different locations were significant, therefore for uniformity of MSe, the experimental locations were divided into two groups. Linn and Binns parameter, coefficient of variation of grain yield and rank method were used for determination of stable cultivars/lines. Results of combined ANOV A in the first group (Maragheh, Sararood and Ardebil) showed that interaction effects of year x location and year x cultivar were significant (P ≤ 0.01), and also differences among cultivais/lines in grain yield were significant at 5% probability level. Bread wheat cultivars had the highest grain yield and, in durum wheat, lines no. 2 and 4 with 1585 and 1566-1 kgha,respectively were the superior lines. Lines no.2 and 18 had the most stability and grain xield among genotypes. In this group line no.18 with facultative growth habit is recommended for these regions. In the second group (Shirvan, Uromieh and Ghamloo) the effects of year, location, cultivar and also interaction effects of year x location and year x location x cultivar on grain yield were significant. After bread wheat cultivars that had the highest grain yield, durum wheat lines no. 9 and 18 with 756 and 734 kgha-1, respectively were the highest yielding genotypes. Regarding grain yield, results of stability and adaptability analysis and growth habit, these two lines are recommendable for growing in these locations.

Berseem clover is one of leguminoes forage crops which its yield performance depends on interactions among climatic, genetic and agronomical factors. This investigation was carried out in Karaj region to determine the growth degree days of different growth stages and seed and forage yield production of Berseem clover in four planting dates (16 March, 4 April, 25 April and 15 May). The results showed that 1060 (68 days) and 503 (25 days) GDDs are needed for forage production in the first and second cuts, respectively and 2000 GDD (120 days) for seed production. Among the different growth stages, branching and anthesis stages were the longest (31 days) and the primary leaf stage was the shortest (3 days) periods. The results demonstrated that the period from planting to the first cut was 75 days in the first planting date (the longest period), and 65 days in the third and forth planting dates (the shortest period).Although the longer period was needed to reach the first cut at the first planting date, its GDD (877 GDD) was lower than those of the third and forth planting dates (1132 and 1256 GDD respectively). This period was 25 days in all planting dates, but the GDDs accumulated during this period were 503.2 GDD. In general, Berseem clover needs 1563 GDD (93 days) for forage production with two cuts and 2000 GDD (120 days) for seed production. Based on these results, early planting date is recommended for forage and seed production.

Starch of two lines of naked barley was extracted by three different methods of washing. The apparent amylose content was determined with the same standard method, which recently has been modified for use with samples of 2-3 seeds of cereal. In the present experiment a factorial design (2 x 3 x 3) was used. The starch was extracted by soaking the seeds overnight in dilute 0.2M ammonia solution grinding in 0.5M NaCl solution in a microfuge tube with an appropriate pestle and decanting the starch slurry. Then it was washed in 4M NaCI, SDS 5% and acetone. The results of apparent amylose content of this method statistically were better than the two others. With present selected method the apparent amylose content ranged from 18 to 34% was determined for 145 accessions of naked barley. This range is considered sufficiently broad to allow amylose content to be further diversified through the working with more lines and breeding.

Three forage sorghum cultivars named KFS 1, KFS2 and KFS3 were studied for determination of the most suitable plant density, in factoril experiment based on a randomized complete block design in three replications at Karaj in 2001-2002. Plant densities were 167, 208, 278 and 417 thousands plants per hectare. Ammonium phosphate on the base of P2O5 Was applied at 115 kgha-1 and total nitrogen used was 183 kgha-1 at four times. Four traits including green fodder, dry matter, plant height and tiller number were measured in each cuting. Harvesting was conducted from 7.8 m2 area. Two years data were analyzed in combined analysis and the means were compared with Duncan's multiple range test (DMRT) method. Results showed significant differences between years (except for plant height), cultivars (except for tiller No.), year x cultivar interaction (except for tiller No.), plant density ,year x Plant density interaction (except for dry matter), cultivar x plant density interaction (except for plant height at 5% level probability) and year x cultivar x plant density interaction (except for plant height)at 1% level of probability. By means comparison with DMRT showed, all of studied traits ranked in the first group at first year. The cultivars KFS1 and KFS3 with 126.7, 124.5 tha-1 of green fodder, 24.38, 23.05 tha-1of dry matter, 186 and 187 cm of plant height ranked in the first group. KFS2 produced the lowest dry matter yield with an average of 20.18 tha-1. Plant densities of 278 and 417 thousands plant ha-1 had the highest and lowest dry matter yield, respectively. The tiller number differed significantly in the first and second cuts, but there were not significant difference in the means of tiller number among the studied cultivars.

In order to examine drought tolerance of cotton genotypes at seedling growth stage, an experiment was conducted in greenhouse using 40 cotton genotypes and three drought levels (-1, -4 and -8 bars) in factorial arrangement with 3 replications and a randomized complete block design. Matric potentials were created based on soil moisture release curve. Percentage emergence, emergence rate, leaf number, leaf area, total dry weight (root and shoot) and root/ shoot ratio were evaluated as affected by metric potentials. Results showed that all traits, except root/ shoot ratio, were decreased with increase in drought stress. Among the measured traits, leaf area was more sensitive and decreased greatly. Drought stress increased root/ shoot ratio, so that the greatest values were obtained at-8 bar. Overall, the genotypes Bulgar 433, Tabeladila and N.O.200 at emergence stage and the genotypes Siokra, Barbadens, Bulgar 433 and Tabeladila at seedling growth stage were the most tolerant, while the genotypes Narabry and Sahel at emergence stage and Narabry, N.O. 259 and Delta pine at seedling growth stage were the most sensive genotypes.

Common root and crown rot, mainly caused by the soil fungi, Bipolaris sorokiniana and Fusarium spp. is a serious problem in some wheat growing areas in Fars province, Iran. Resistance or tolerance is an important control strategy In a study conducted during 1995-1997, 114 advanced lines and cultivars of wheat (Triticum aestivum L.) were screened in a highly infested field at Bayza district, Fars province for reaction to the disease. Ten lines and cultivars showed considerable field resistance or tolerance. Among these, six yellow rust resistant/tolerant lines or cultivars were selected and compared for yield in a randomized complete block design with four replications established in a highly infested soil at Estahban (moderate ) and Ghir-Karzin (warm) regions of the province in 1997-98. Cultivar Marvdasht and line M-75-20 had the highest yields in the moderate and cultivar Chamran in the warm regions of the province (p=1 %). Based of these results, cv. Marvdasht is recommended to be planted in the infested fields of the moderate,- and cv. Chamran in the warm areas of the province.

Drought is the most important a biotic stress which play an important role in decreasing genetic variation and crop yield in the world. This investigation was carried out with complete series of substitution lines (lA, 2A, ... 7A; IB, 2B, ...7B and ID, 2D, ... 7D) and T. aestivum cv. Sheynne and T aestivum cv. Chinese spring as donor and recipient parents, respectively received from Agricultural Research Institute, Hungarian Academy of Science, Martonvasar, to analyse genetic control of drought tolerance in Sheynne cultivar. Results showed genetic" variation among substitution lines: Genetic variation indicated genetic differences among chromosome locations. This made it easy to screen chromosomes having drought tolerance QTLs; Substitution lines having chromosomes No. 6D, 2D and 5A showed maximum relative water content (RWC). Substitution lines having chromosomes No. 7A, 2A, 4D, 6D, 1D and 2B showed maximum drought tolerance index (DTI). Chromosomes No. 7 A, 2B, ID, 2D, 6D, 3D and 4D showed high multiple selection index (MSI) and MSI had significant high correlation with DTI and physiological indices including RWC and relative water loss (RWL). Results of genomic analysis in Sheynne cultivar indicated that D genome with 43.11 % selection efficiency based on MSI had the most influence on controlling drought tolerance. Results of cluster and discriminate analyses based on DTI and MSI indicated that chromosomes No. 7A, 4D, 6D and 2D are the most important cluster in controlling drought tolerance. Conclusion is that chromosomes No. 7A, 4D, 6D and 2D had the most drought tolerance QTLs in Sheynne cultivar.

The main purpose of this experiment was to evaluate the characteristics of seed samples of thirteen ecotypes of Medicago, Bromus and Agropyron in response to Fusarium solani and Fusarium oxysporum. Origin of seeds used in the experiment, was either Iran or other countries. The seed sample of each ecotype was exposed to two concentrations of spores of F. solani, F. oxysporum. (20 x 104 and 29 x 104 spores/ml for F.solani and 45 x 104 and 59x 104 spores/ml for F. oxysporum). The inoculated seeds of ecotypes were considered as treatments, and non-inoculated seeds as control. The main characteristics of the inoculated seeds including percent and speed of germination, length of root and shoot, and vigour index were compared with those of non-inoculated seed for each ecotype. The results showed significant differences among ecotypes and fungal species for all the measured characteristics. The effect of fungal treatment on germination speed was more than that of germination percentage.

Dialer crosses have been used in genetic research to determine the inheritance of important traits among a set of genotypes and to identify superior parents for hybrid or cultivars development. Genetic control of infection type of stripe ruts was studied in a half-diallel design using six wheat cultivars, Tiritea (a susceptible check), Tancred, Kotare, Otane, Karamu and Briscard. These cultivars and their 15FlS. were evaluated by three stripe rust path types 7EI8A-, 38EOA + and 134E134A +. For each pathotype a randomized complete block design with three replications was conducted with 21treatments. The biplot method was arranged by the first two principal component (PCs). Analysis of variance showed significant differences between 21 treatments for infection type. Changing the path types caused reversal of the domillance in most of the crosses. Briscard for the path types 38EOA+and 134E134A+, and Kotare for the pathotype 7E18A- had the highest GCA effects for infection type, so they can be used in breeding programs for development of resistant cultivars to stripe rust. The highest negative SCA was observed in crosses of Kotare x Karamu for 7EI8A-, Tiritea x Otane for 38EOA+ and Briscard x Kotare for 134E134A+. These SCA values indicate the presence of dominance for the lower infection type. The results indicated that infection type, as a component of resistance is under genetic control and seiection for this character would be effective in wheat breeding programs.

Information on germplasm diversity and relationships among elite materials is fundamentally important in crop improvement programs and especially will increase the efficiency of procedures used in hybrid breeding programs. In order to assess the possibility of grouping the maize inbred lines in maize breeding program, 52 inbreeds were evaluated for 40 morphological traits using randomized complete block design in three replications for two years(2002- 3) in experimental field of the Seed and Plant Improvement Institute, Karaj, Iran. According to the analysis of variance, constancy and broad-sense heritability, 25 traits were selected for grouping the lines. Cluster analysis. based on standardized morphological data assigned the lines in four groups. According to step wise discrirnnant analysis, among the 25 traits, the most important ones were ear conicalness index, pedancul length out of flag leaf, kernel rows, length and area of flag leaf. The first seven principle components(PC) accounted for 83.5% of total variance. In the first PC, pedancul and ear shape were the most important, while, the second PC, described variations in ear diameter and kernel shape. The cluster analysis distinguished four clusters with seven PC clusters. The grouping of lines using these PCs, was in good agreement with morphological data. Some lines located in different groups, comparing the first groups. Concerning the independence of each PC, this grouping can be considered as a primary grouping for maize inbred lines.