Seed and Plant
Year:2004 | Volume:20 | Issue:3|Papers Count:11

Development of wheat cultivars with high and stable yield for different environments is very important in breeding programs. In this study, 19 winter and facultative wheat genotypes along with a check cultivar (c.v. Shahreeyar) were studied for grain yield and its stability at Karaj, Arak, Ardebil, Hamedan, Mashhad, Jolgeh Rokh and Tabriz Agricultural Experimental Stations in 1997-2000 cropping seasons. The experimental design was RCB with four replications. Results of combined ANOVA showed that interaction of genotype x location x year was highly significant. Using different stability analysis methods such as CV, regression analysis and simultaneous selection for yield and stability showed similar results. Genotype C75-5 (OWL 85256*-3oh-*O-*Eoh) was determined as the superior for grain yield among all genotypes in almost all methods. Results of the study on harvest index (HI) indicated that the genotype C-75-15 (Bez- 2B/Cgn/Vratza) was superior for HI stability. Although, the correlation coefficient between grain yield and harvest index was positive and significant (r =0.36**) however, stabilities of these two traits among the genotypes, were not similar.

In order to study the ecophysiological traits of safflower in different intensities of drought stress in summer planting, three safflower lines selected from Isfahan landraces (Isfahan-8, Isfahan-24 and Isfahan-44) in three plant densities (31, 20 and 13.3 plant/m2) with four irrigation regimes (three irrigations after 70,140 and 210 milimeter evaporation from class A pan up to physiological maturity and one after 140 milimeter evaporation up to complete flowering) were used in north-west of lsfahan. The experiment was carried out in northwest of Isfahan in a rondomized complete block design with a splitsplit plots layout in three replications during 2001 and 2002. Stress intensity (SI) was calculated and the effects of drough stress on some ecophysiological characters such as grain water use efficiency (GWUE), biomass radiation use efficiency (BRUE), grain radiation use efficiency (GRUE), oil radiation use efficiency (ORUE), leaf area index (LAI), specific leaf area (SLA) and plant damping off rate (PDR) were evaluated. The results showed that reduction in water use in canopy (lower than after 70 milimeter) resulted in an intensive stress in canopy of sofflower (SI was about 0.45 and 0.42 in 2001 and 2002, respectively in irrigation after 140 milimeter treatment). With more decreased water use, increase of stress intensity was very little. Drought stress reduced GWUE, BRUE, GRUE, ORUE, LAI and SLA, but PDR was increased.

In order to study the effects of row spacing and seed rate on vegetative characters, yield and yield components of rapeseed (Quantum cultivar), an experiment was conducted at Agricultural Research Station of Gonbad during 2001-2003. Three row spacings (12, 24 and 36 cm) and three seed rates (6, 8 and la kgha-1) were arranged in a factorial form in a RCBD with four replications. The results of combined analysis showed that year significantly affected the number of days from emergence to flowering and physiological maturity, duration of flowering, plant height, lodging, the number of harvested plant and grain per pod, 1aaa-grain weight, oil percent and grain and oil yield at 1% level. The number of days from emergence to flowering and physiological maturity, duration of flowering, plant height, lodging and 1000-grain weight in the second year were more than those of the first year of experiment because of the lower temperature and more rain in the second year, whereas the number of harvested plants, grain per pod and grain and oil yield in the first year were more than those of the second year of experiment. The effect of row spacing on the number of days from emergence to flowering, plant height and the number of pod per plant were significantly different at 5% level and on the number of grain per pod, 1000-grain weight and grain yield at 1% level. The number of pod per plant, the number of grain per pod and grain yield increased with decrease of row spacing. Treatment of 12 cm row spacing had the highest grain yield (4626 kgha-1), whereas 36 cm row spacing had the lowest grain yield (3093 kgha-1). The interaction between year x row spacing had significant effect on the lodging at 1% level. As a whole, plant lodging happened just in the second year of experiment and it increased with increase of row spacing significantly. Lodging increased with increase of seed rate, whereas the number of grain per pod and grain and oil yield decreased with increase of seed rate. The grain yield of 6, 8 and 10 kg seedha-1 treatments were 4061, 3698 and 3622 kgha-1, respectively. The 12cm row spacing and 6 kg seed ha-1 treatment produced the highest grain yield (5044 kgha-1).

Presence of genotype x environment interaction necessitates evaluation of genotypes in a wide range of environments to find desirable genotypes. Twenty four winter canola (Brassica napus L.) genotypes were evaluated in nine cold and temperate regions in 1999-2000 and 2000-2001 cropping seasons using a randomized complete block design with four replications. After homogeneity test for error variances, combined analysis of variance was performed assuming genotype effect as fixed, and years and locations effects as random. Effect of genotype was highly significant. Except the genotype x year interaction effect which was non-significant, other interaction effects were highly significant. The statistical methods that used for measuring yield stability were Eberhart and Russell's deviation from regression parameter, coefficient of variation (C.V.), Wricke's ecovalence , Shokla's stability variance and Finlay and Wilkinson regression coefficient. Analysis of the grain yield by the method of Eberhart and Russell showed significant difference for the genotype x environment (linear) interaction. According to the classification of genotypes based on the mean of grain yield, coefficient of regression and deviation from regression, genotypes SLM046 and Parade with 3.43 and 3.34 tha-1 of grain yield, respectively and with well adaptability in all environments, were selected as desirable genotypes. Meanwhile, using other stability analysis methods (coefficient of variation, Shokla's stability variance and Wricke 's ecovalence) introduced genotypes such as Parade, SLM046, Fornax, Licord and Colvert as more stable and adaptable genotypes which already confirmed the results obtained from Eberhart and Russell's methods.

In the present study eight symptoms of Plasmopara halstedii (Farl) Berl and de Toni including damping-off, sporulation on cotyledons and true leaves, sporulation on cotyledons, stunting, leaf mosaic or chlorosis, deformation, hypocotyls lesions and root reduction on the inoculated plants were compared as disease infection characteristics for assessment of resistance and suceptibility of sunflower cultivars and hybrids. Three days-old seedlings were inoculated with spore suspension of P. halstedii using whole seedling immersion method (WSI). Reactions of cultivars were recorded 15 days later. A strong correlation between the above symptoms, and sporulation on cotyledons and true leaves (SCL) as the main infection characteristic of the disease was determined. The most suitable regressional model for resistance determination was calculated based on mosaic (M), stunting (S), hypocotyle lesjons (HL) and root reduction (RR) symptoms. Among other regressional models tested for resistance determination, another model with high R2 value was also determined using only mosaic symptom.

The green fodder, grain yield and yield components of three triticale and two barley cultivar were compared in a split plot experimental design in Moghan Agricultural Research Station during two consecutive cropping seasons (2000-02). The main plot was allocated to harvested and non-harvested green fodder treatments, and the subplot was assigned to three triticale cultivars (4108, 4116 and Mus"S"/Beta"S") and two barley cultivars (Dasht and LB). Combined analysis of variance for green fodder indicated significant differences among the cultivars (P<0.01).The highest green fodder (21.01 tha-1) was obtained from barley cultivar LB. Three triticale cultivars 4116, 4108 and Mus"S"/Beta"S" produced 17.24, 15.79 and 14.1 tha-1 green fodder, respectively. The differences among the cultivars were not significant. Barley cultivar Oasht had the lowest green fodder. Combined analysis of variance for agronomic characters showed significant difference among the cultivars for grain yield, plant hieght, spike length, number of kernels per spike and 1000kw (P<0.01).The highest and lowest grain yield belonged to triticale cultivar 4116 and barley cultivar Dasht, respectively.

This research was carried out to study the effect of tea wastes in composting of shredded and non-shredded tree bark and also the effects of mixes on growth of French Marigold (Tagetes patula L.). Tea wastes were mixed with shredded and non-shredded tree bark in volume ratios 0%, 25%, 50%, 75% and 100% and maintained in 1m3 wooden boxes for composting. After composting process, samples were taken and physical and chemical properties were measured. To study the effects of mixes of the obtained composts on growth of French Marigold, an experiment was designed in a completely randomized design (CRD), with nine treatments in four replications. Then French Marigold was planted in compost mixes. Results showed that tea wastes in 50% and 75% ratio significantly affected the composting of shredded and non-shredded tree bark, and accelerated the composting process of non-shredded tree bark, therefore, by use of tea wastes, the shredding of the tree bark can be omitted and tshe cost of composting will be decreased. The mixes affected significantly the top fresh and dry weight, plant height, number of lateral shoots and number of opened flowers of French Marigold. The properties of physical and chemical were also suitable. C/N ratio of these mixes was very low and showed that tea wastes notably reduced the C/N ratio of tree bark.

Linkage maps are essential for genome studies in different crops. The objective of the study was to construct a linkage map using Khatoonie, a local melon accession in Iran because of its characteristics as a main accession in Iran. Hence, a cross between Khatoonie and the French line Charentais was made to obtain the F2 mapping population. To construct map, a total 42 RAPD primers was used. Linkage analysis indicated that 109RAPDs assigned to 13 linkage groups with a total length of 504.7 cM and distance between adjacent markers in average was 5.2 cM. Adding more markers to this basic map is on going because of being in lack of any linkage map for germplasm of Iranian melon. This map can be used in marker assisted breeding projects and for map-based cloning.

In order to evaluate the effects of seed quality on establishment and growth of seedling of wheat cultivars in field conditions, two years experiment (2000 and 2001) was conducted at Ramin Agricultural and Experimental Field in Ahvaz. In the first year, effects of water stress and different seed harvesting periods on seed quality of durum wheat cultivars (Chenaltar and Showamald) and bread wheat cultivar (Falat) were studied. To determine the quality of seeds, a part of seeds were tested in laboratory for germination and seedling growth, then percentage of germination, germination rate and seedling dry weight were determined. Based on the resultus of the first year, in the secand year seeds were planted in field to determine the effects of their quality on seedling establishment and grain yield. Experimental design was factorial based on RCBD. Emergence rates, percentage of stand establisment and grain yield for all treatments were recorded. Results showed that emergence rate, stand establisment and grain yield were significantly affected by wheat cultivars and seed quality. According to the results, Seed quality and wheat cultivars had influenced on stand establishment and early growth through the rate and percentage of seedling emergence. This effect was prolonged throughout the crop life cycle and ultimately influenced grain yield. Significant correlation of seedling emergence (%) with stand establisment and grain yield, indicated that increase in grain yield resulted from more matured seeds (harvested at 44 and 58 days after anthesis) compared with less matured seeds (harvested at 12, 18and 25 days after anthesis) was mainly due to higher stand establishment of more matured seed. Also results showed that seedling growth had the highest correlation with percentage and rate of emergence, stand establishment and grain yield. Therefore, seedling growth test is recommended as an appropriate test to evaluate the seed vigour of wheat cultivars.    

An experiment was conducted at Ecbatan Research Station in Hamedan in two years (1998-99) to study the effects of planting density and methods and also seed clove size on yield of Hamedan garlic. The experiment was in factorial 3 x 3x 3 in randomized complete block design with three cultivation methods, three sizes of seeds and three plant densities in three replications. The data were analized each year and at the end of the second year, combined analysis was done on the data. The results showed that the effects of plant density and seed size on yield were significant, but the cultivation method did not show any effect on yield. Density of 740 thausand plants/ha, seeds clove of 5/5-7 g in weight and planting on two rows, were the best treatments for getting the highest yield in Hamedan conditions.