نشریه نهال و بذر
سال بیست و سوم شماره 2 (تابستان 1386)

Conservation tillage practices and proper planting depth are very important for early emergence before the first effective rainfall in dryland cold regions. An experiment was conducted at the Dryland Agricultural Research Station of Maragheh, located in the northwest of Iran, during 2001-2004 to determine the proper planting depth for barley in dryland. The treatments were, three barley genotypes (Yesevi , Obruk and ICB-111838) as the main plot and three planting depths (2-4, 4-6 and 6-8 cm) as subplot designed in strip plot with three replications. Data were taken from yield and other traits during the growth period. Results showed that planting depth significantly influenced number of heads per square meter, biomass and grain yield. The highest number of heads per square meter (296 heads) and the highest grain yield (2750 kgha-1) were obtained from 4-6 cm planting depth. Differences between grain yield of genotypes were significant (P < 0.01). The maximum grain yield (2780 kgha-1) was gained form Yesivi genotype. Number of heads per square meter was the main effective factor on yield increase.

To study yield stability in some high yielding cultivars and lines of safflower, twenty five lines and cultivars were evaluated in a lattice design for three years (2000-2003) in Sararoud Dryland Agricultural Station in Kermanshah. Stability analysis based on Eberhart and Russell method showed significant difference at 1% probability level among genotypes for seed yield. Interaction effect of genotype and year was also significant. Line 338 and cultivar PI-258417 having yields more than total average (930.94 and 1031.92, respectively), line slope less than 1 and lower deviation variance of line were found to be more suitable for entazari plating under rainfed conditions of Kermanshah.

Lilium is one of the highly valuable ornamental plants in national and international flower markets. One of the most effective methods for propagation of Lilium is tissue culture, preferably through direct somatic embryogenesis. In the resent project, the effects of various concentrations of Picloram (0, 1, 2, 3, 6 and 9 mgl-1), Thidiazuron (0, 0.5, 1, 1.5 and 2 mgl-1), α-Naphtalene Acetic Acid (1.5 mgl-1) in combination with Thidiazuron (0.08, 0.2 and 0.4 mgl-1), 2,4-Dicholorophenoxy Acetic Acid (2.5, 5 and 10 mgl-1) in combination with Benzyl Amino Purine (0.25 mgl-1) and types of explant (basal, central and distal part of bulb scale) was investigated on direct somatic embryogenesis induction of Lilium longiflorum var.Ceb-Dazzle. The explants were surface sterilized and then were cultured on MS medium supplemented with 3% sucrose, 0.3% Phytagel and various concentrations of mentioned growth regulators. According to the results, it was found that 2 mgl-1 Picloram was the most effective concentration to induce direct somatic embryogenesis in L. longoflorum, giving the highest number of embryos (on average 30.6 embryo/explant) on central explant. Thidiazuron alone or in combination with α-Naphtalene Acetic Acid in various concentrations was not able to induce somatic embryogenesis, but caused bulblet regeneration. Similar results were obtained for 2,4-Dicholorophenoxy Acetic Acid and Benzyl Amino Purine treatments. Induced somatic embryos were transferred to MS media without growth regulators for further development and maturation. The matured plantlets were acclimatized and transferred to in vivo conditions.

  Flag smut of wheat (Urocystis agropyri) has been recently developed in some fields in Khuzestan province and causes sever damages on wheat. Infection was estimated up to 45% in these fields. The most important and economical control method is use of resistant cultivars. This experiment was conducted to evaluate some commercial and promising wheat cultivars and lines for resistance to disease. For this, 186 commercial and promising bread and durum wheat cultivars and lines, after artificially infection with smut spores, were sown in disease nursery. Each cultivar was planted in two rows with one meter length. This experiment was conducted in 2003-2004 with one replication and in 2004-2005 with two replications and on the basis of average of infected Plants, reactions were evaluated. The results of two years showed that among 186 cultivars and lines, 22 were very susceptible with infection between 20.61 to 52.45 percent, 33 were susceptible with infection range from 10.41 to 19.05 percent, 25 were moderately susceptible with 5.21 to 9.67 infection percent, 18 were moderately resistant with infection percent between 2.36 to 4.49, 36 were resistant with infection less than 2 percent and 52 were immune. The majority of bread wheat genotypes were very susceptible, susceptible, moderately susceptible or moderately resistant.Form 80 evaluated durum lines and cultivars, 50 lines and cultivars were immune and 30 were resistant to the disease, and only two bread wheat cultivars were immune. Â

In order to determine the tolerant cultivars to charcoal rot disease,caused by Macrophomina phaseolina,121 soybean lines were evaluated in field conditions during 2001 and 2002. Initial densities of the fungal inoculum was 35 microsclerotia per gram of soil. The experiment was carried out in a simple lattice square design with 121 plots in two replications. In each plot one soybean line was planted on three rows (5m long). Distance between rows was 50 cm and between plants 10 cm. Infected plants were differentiated from healthy ones, based on the level of colonization and presence of microsclerotia on the lower parts of stems and roots. The results of combined analysis of variance showed significant differences between soybean lines in reaction to the disease. Lines exhibited reactions from moderately resistance to high susceptibility (up to 100% infection). Generally,the late maturity groups of soybean were more tolerant to the disease. Lines B.P-692, J.K-695 and K.S-69035 showed the highest tolerance to charcoal rot. Based on the results in this study and the qualitative and quantitative agronomy characteristics, two lines J.K-695 and B.P-692 were selected as the suitable cultivars and introduced as Sari and Telar for cultivation in Mazandaran region.

  Seed and oil yield, yield components, agronomic traits and oil percentage of 18 canola spring genotypes were evaluated in a two year experiment with different climate conditions at Agricultural Research Station of Gonbad during 2002–2004. The experiment was a randomized complete block design with four replications. The results of combined analysis showed that the effect of year was significant on the number of days from emergence to physiological maturity, resistance to lodging, the number of grains per pod, 1000 seed weight and seed and oil yield at the 1% level. In the second year of the experiment, decrease in the number of days from emergence to physiological maturity resulted significant decrease in 1000 seed weight, however existence of good climate condition, greater sunshine during flowering and seed formation periods resulted in increase in seed and oil yield (because of the decrease in lodging and increase in the number of seed per pod). The seed yield of the second and the first year of experiment were 3318 and 2359 kgha-1, respectively. The 1000 seed weight of Hyola 401 and Hyola 420 hybrids were more than those of other genotypes. The 1000 seed weight of Foreign Hyola 401, Safiabad Hyola 401, Borazjan Hyola 401 and Hyola 420 hybrids were 4.59, 4.64, 4.52 and 4.72 g, respectively. Option 500 had the highest oil percent (45.61%).The Hyola 420 hybrid had the highest seed (3560 kgha-1) and oil (2049 kgha-1) yield. Regarding of high yield and good vegetative characters, it seems that this hybrid and Hyola 401 can be recommended for planting in east part of Golestan. Â

Maize Rough Dwarf Virus (MRDV) and Iranian Maize Mosaic Virus (IMMV) are dominant and common viral diseases in Isfahan province. Their transmission is by Laodelphax striatellus . In order to study the effects of planting date and commercial maize hybrids on infection of these viruses, an experiment was conducted in Kabutarabad Agricultural Research Station in Isfahan for two years (2000 and 2002). The experiment was in a spilt plot design that the main factor was various planting dates (5May, 24May and 10June) and sub factor was corn hybrids KSC704, KSC647, KSC604 and KSC301, with four replications. Mean Percentages of plants infected with each virus were determined by samples collected from two central rows in each treatment. Data were converted to Arcsin x/100 and were compared by Duncan’s multiple range test. Results showed that infected plants to IMMV was lower in the third planting date and was significantly different from other planting dates. Percentage of plants infected with IMMV in different hybrids were significantly different. Hybrid KSC301 had the lowest and KSC704 had the highest percentage of infected plants. Mean Percentage of plants infected with MRDV was significantly different in various planting dates. The highest and lowest infections were found in the second and third planting dates, respectively. Mean percentage of infected plants of hybrids to MRDV was significantly different in all plating dates. Hybrid KSC301 had the lowest and hybrids KSC604, KSC647 and KSC704 had the highest infected plants respectively.

  Maize Rough Dwarf Virus (MRDV) and Iranian Maize Mosaic Virus (IMMV) are dominant and common viral diseases in Isfahan province. Their transmission is by Laodelphax striatellus . In order to study the effects of planting date and commercial maize hybrids on infection of these viruses, an experiment was conducted in Kabutarabad Agricultural Research Station in Isfahan for two years (2000 and 2002). The experiment was in a spilt plot design that the main factor was various planting dates (5May, 24May and 10June) and sub factor was corn hybrids KSC704, KSC647, KSC604 and KSC301, with four replications. Mean Percentages of plants infected with each virus were determined by samples collected from two central rows in each treatment. Data were converted to Arcsin x/100 and were compared by Duncan’s multiple range test. Results showed that infected plants to IMMV was lower in the third planting date and was significantly different from other planting dates. Percentage of plants infected with IMMV in different hybrids were significantly different. Hybrid KSC301 had the lowest and KSC704 had the highest percentage of infected plants. Mean Percentage of plants infected with MRDV was significantly different in various planting dates. The highest and lowest infections were found in the second and third planting dates, respectively. Mean percentage of infected plants of hybrids to MRDV was significantly different in all plating dates. Hybrid KSC301 had the lowest and hybrids KSC604, KSC647 and KSC704 had the highest infected plants respectively. Â

For determination of optimum planting density and harvesting date for potato cultivars, a split split plot experiment in basis of RCBD design with four replications was conducted for two years (2001-03) at Behbahan Agricultural Research Station. Main plot consisted of three cultivars Arinda. Piccaso and Sante. Sub plot were three planting densities 5.3, 7.6 and 8.9 plants per square meter (15 75, 20 75 and 25 75 cm) and sub sub plot were three harvesting dates of 30 April, 15 May and 30 May. Combined analysis of variance showed significant effects of cultivar, planting density and harvesting date on total yield, marketable yield and yield components. Effects of cultivar and harvesting date on unmarketable yield and its components (small tubers, rotted tubers and secondary growth) were also significant. Effect of planting density on small and rotted tubers were not significant. Cultivar Sante produced the heighest total and marketable yield. Increase in planting density decreased mean of tuber weight and tuber number per plant. Planting density of 8.9 plants per square meter produced the highest total and marketable yield. The highest total yield was produced in the latest harvesting date, but unmarketable yield was high in this harvesting date. Based on the results, cultivar Sante, density of 8.9 palnts per square meter and harvesting date of 15 May can be recommend for Behbahan region.

Date palm spider mite is one of the major pests of date palm in Khuzestan.This pest damages fruits in orchards. In the present study responses of 30 native date palm cultivars of Khuzestan were evaluated by assessment of pest infestation severity and fruit damage characteristics. Based on the responses, cultivars were clustered into four groups as very highly infested cultivars including Liloei, Berhee, Zahedi, Deiri, Ashkar, and Berim, highly infested cultivars including Halavi, Beliani, Sovidani, Hadak, Shkar, Bent Alsabae, Dagal zard, Khazravi and Sayer, moderately infested cultivars including Bobki, Chabchab, Mashtom, Jahromi, Amobahri, Dagal sorkh, Fersi and Hadal and less infested cultivars including Khasab, Hamravi, Hasavi, Ashagh, Jozi and Gantar. The characters such as bunch weight, fruits number, fruit skin thickness had significant correlation with the date palm spider mite injury. Other characteristics did not show significant correlation with the mite injury.

Eight promising lines of bread wheat which had been selected through the preliminary and advanced traits, together with two check cultivar Shiroudi and Tajan were evaluated for yield, adabtability and response to cereal diseases in an on farm experiment conducted in two sites in Moghan. Combined analysis of variance on yield and yield components showed significant differences of lines in yield and other traits. Lines Sw89.3064/Star… and Attila/Milan with 5.7/8 and 5.709 tonha-1 had the highest yield in both sites. Although other lines produced yield as high as the check cultivar Shiroudi, but due to high resistance or tolerance to yellow rust, leaf rust, fusarium head blight and powdery mildew which are prevalent diseases in the region, two lines Sw89.3064/Star… and Sha4/Chil were selected as superior lines in this experiment.

  Dorfak (Line No.424) is a single cross derivative between Sepidrood, a high yielding improved rice cultivar used as male parent and Salari, a traditional landrace with premium cooking quality and poor in yield as female parent. The cross was attempted in 1988 and the F2 generation onwards of the cross was raised in the pedigree breeding approach. The F2 single plant selections were based on early, synchronous flowering habit, increased number of tillers, high yielding potentials with reduced plant height and resistance to blast disease. However, the selections based on grain quality were initiated from F5 generation (1994) onwards. Amongst the different selected pedigree families of the selections made earlier, the line 424 was identified as high–yielding, semi-dwarf, resistant to blast and possessing good cooking quality characteristics in 1995. This selected line was entered into preliminary yield trials and advance yield trials in comparison to improved cultivars like Khazar and Sepidrood. Multi-environmental trials were conducted at three sites over 3 years (1996-98) and the pooled analysis of these trials averaged over sites and years, revealed highly significant differences (P 1) for yield. The line 424 performed consistently, yielding in the range of 5.5 to 6.3 tha-1 with an yield advantage of 17.4% over improved cultivars like Khazar while 34.5% over traditional check cultivar Binam in three on-farm trial sites. The selected line 424 was named as Dorfak and was released for cultivation in Guilan province in 2002. Dorfak is a semidwarf (plant height 110 cm), aromatic, short duration cultivar (120 days) with 17 productive tillers, 115 grains per panicle, good grain and cooking quality features. Rice kernel characteristics clearly showed that line 424 was a highly transgressive in nature especially for kernel length and length/width ratio. However, for all other grain quality traits, Dorfak was much closer to the traditional landrace parent i.e. Salari. Dorfak, was released in 2002 for cultivation, to a large extent combined the premium cooking quality features of the traditional landraces and the yield of improved cultivars, hence becoming popular with the farmers and consumers alike.   Â