Pyrodwarf and OH × F69 rootstocks are the main clonal rootstocks for pear trees in Iran. This research was conducted to compare growth and nutrient uptake in different commercial pear cultivars including; Louise Bonne, Dargazi and William`s Duchesse on Pyrodwarf, OH × F69 and Dargazi seedling rootstocks in two years in the nursery. Both clonal rootstocks inducted higher growth in cultivars. Cultivar Louise Bonne had the highest growth on Pyrodwarf rootstock. Calcium content varied from 1.4% to 1.5%, but nitrogen, phosphorus, potassium and manganese showed higher variation, and the highest content of these nutrients were observed in cultivar Dargazi on Pyrodwarf rootstock. The lowest and the highest variations were observed in zinc and iron content, respectively. In addition, about 30% of total iron of the leaves was active iron, indicating high level of active iron in pear in comparison with other fruit tree species. In all graft combinations, variation in micro and macro nutrients contents were in optimum range. Comparison of nutrient contents with active lime level in soil indicated that the range of 10-15% active lime in soil would not hinder growth and nutrients uptake of plants.

Common smut is an important disease of maize that occurres in many maize growing countries as well as in Iran and causes considerable damages on yield. Damage of the disease varies by race of the pathogen, susceptibility of host, agronomic procedures and nitrogen fertilizers application on crop. Damages up to 50% on susceptible cultivars have been reported frequently. Control of the disease through common methods is difficult and use of resistant cultivars is the best method for control of the disease. In the present study response of 29 maize genotypes including 16 hybrids and 13 parents to prevalent races of the pathogen was evaluated in field condition in Karaj and Isfahan in 2014. All ears of plants in each plot were inoculated with a suspension of sporidia of five isolates of the pathogen and disease severity was scored at the end of the season and respose of genotypes was evaluated. Based on the results, only line S61 was resistant and the remaining were moderately resistant except OH43/1-42 and KE 78008/212 which were highly susceptible. Among hybrids, KSC 201 (K1263/17 × S61) was highly resistant, KSC 400 (KE 72012/12 × KE 1263/1), KE 75016.321 × K 1264/5-1 and KSC 260 (K 615/1 × K 1264/5-1) were resistant and the remaining hybrids were moderately resistant or moderately susseptible.

To evaluate resistance of maize late maturity lines and hybrids to southern corn leaf blight disease (Bipolaris maydis), an experiment was performed in randomized complete block design with three replications in Karaj and Sari during 2013, using seventeen maize lines and hybrids. Artificial inoculation was carried out two times, first by injection of spore suspension into the whorls of the plants at 3-4 leaf stage, and the second by inoculation of infected sorghum seed with the pathogen into whorls by bazooka at 6-8 leaf stage. Disease severity on leaves of inoculated plants was scored one month after the second inoculation. The results of analysis of variance and means comparison indicated significant differences among lines and hybrids for disease severity. Among eight hybrids, only KSC 708 (A679 × K19) exhibited resistance response (R). Five lines were moderately resistant (MR) among them two commercial lines MO17 and K19 had disease severity less than 10%. Based on the results of this experiment, two latter lines were recognized as favourable sources of resistance to the disease. Line K19 is the paternal parent of hybrid KSC 708 (A679 × K19) which was resistant in this investigation.

Study and comparison of potential forage yield and morphological traits of imported Berseem cultivars with current clover cultivars, will increase diversity among clover cultivars and increase forage production in the country. This experiment was conducted in a randomized complete block design with thirteen cultivars and four replications in Karaj. The two-year combined analysis of variance showed that the effects of year and cultivars were significant for the fresh and dry matter forage yield and morphological traits at 1% probability level. This implies to genetic variation among cultivars and differential effect of year on forage production and morphological characteristics of Berseem clover cultivars. Mean comparisons showed that Polycross cultivar with 70.25 and 16.65 tha-1 and Isoleh-e-Mesri cultivar with 48.84 and 10.70 tha-1 had the highest and lowest fresh and dry matter yield, respectively. The effects of cultivar and year on some morphological characteristics such as plant height was significant and there was a positive and significant correlation between these traits and forage yield. The imported cultivars Wiener, Elite 2 and Selected line, and the local cultivars Tolidi-e-Dezful, Polycross Karaj and Sacromont Mazandaran with 68-69 tha-1 fresh and 16-16.5 tha-1 dry matter yield were the best cultivars, and compared to the control cultivar (Tolidi-e-Karaj) showed 7% and 10% superiority for the fresh and dry matter forage yield, respectively. There fore, these cultivars can be recommended for cultivation in Karaj.

Pepper (Capsicum annuum L.) is a self pollinated crop of Solanaceae family. Iran is known as one of the diversity zones of pepper. For genetic improvement of Iranian pepper landraces, a pure line selection program was conducted in the experimental field of Seed and Plant Improvement Institute in karaj during 2010-2012 cropping seasons. Six Iranian pepper landraces, including Ghalehbala, Khankhodi, Foroumad, Baram, Guilan and Hamedan were evaluated in this program. In the first year, Single plants were selected from each landrace based on quantitative and qualitative traits. In the second year, seeds of each selected plant were planted in separate rows together with their maternal landraces as control and at the end of season, thirty superior lines were selected. Totally 33 entries including 30 selected lines, the Singer hybrid and the two maternal landraces (Guilan and Ghalehbala) were compared in a randomized complete block design with three replications in the third year. Finally 17 high yielding pepper lines with good fruit uniformity and well known marketing quality were selected. The selected lines had significantly higher yield than their material parents, so that the yield of thick peppers was 10-40 percent and thin peppers 16-31 percent higher than those of the material landraces.

To evaluate adaptation ability of twelve cultivated olive cultivars and genotypes in Shirepanahe Ivan of Ilam province, an experiment was conducted based on randomized complete block design during 2009-2010. The variance analysis of data showed that all olive cultivars and genotypes differe significantly in fruit traits in two years. Cultivars had significant differences in fruit fresh, pulp and seed weight. Gololeh Zeiton, Shengeh and Zard cultivars had the highest fruit weight, while Genotype 1 had the lowest. Flesh to pit ratio was less than 5 in all cultivars, so that Shengeh and Genotype 2 had the highest and lowest ratios, respectively. Yield and oil percentage in fresh and dry matter were significantly different at 1% statistical level for cultivar, year and their interaction. Cultivars Zard, Manzanilla, Shengeh and Zard Cultivars had the highest yield compared to the others. The highest oil content in fruit dry and fresh matter was observed in Roghani and Zard cultivars during two years and in Shengeh it was the lowest. Based on yield and oil percent, Zard cultivar was relatively suitable in compare to the others for Ilam province.

Self and cross-incompatibility is one of the limiting factors in sweet cherry production. Scince some self-compatible exotic sweet cherry cultivars have been recently introduced to Iran, this study was conducted to investigate adabtibility of six introduced cultivars Summit, Red Dorfi clone 3, Sunburst, Samba, Blamarka and a local cultivar Siah Mashhad in Khorasan Razavi, Mashhad, Iran during 2010-2013. In most cultivars, flower buds were formed and developed on spurs, however flower formation in annual shoots was also observed. There were significant differences among cultivars for vegetative characters (height, width, crown volume and current season vegetative growth). Cultivars Summit and Sunburst had the highest and the lowest vegetative growth, respectively. There was 10 days variation in start of flowering time. Blamarka and Summit were early (27 March) and late (6 April) blooming cultivars, respectively. The results showed that fruit weight of cultivars was significantly different and Blamarka (3.14 g) and Sunburst (9.83 g) had the lowest and the highest fruit weight, respectively. Summit, Samba, Blamarka, and Siah-Mashhad were self-incompatible and cultivars Stella, Red Dorfi clone 3 clone and Sunburst were self-compatible under Khorasan Razavi province conditions.

To investigate variation and detect the genomic regions controlling quality and quantity of malt extract in barely, a study was conducted using a set of 72 double haploid barley lines as well as their parents (Steptoe and Morex) in RCBD with two replications during the cropping season 2011-12. Different characteristics including germination energy, total percentage of germination, seed dormancy, seed protein, seed malt extract, seed hull, hectoliter weight, seed plumpness, plant height, days to heading, spike length, seeds per spike, peduncle length, one thousand kernels weight, grain yield and harvest index were measured. QTL analysis was done using composite interval mapping (CIM) method for each trait by means of two environments and multiple interval mapping (MIM) method was exploited for assessment of significant interactions between loci, additive × additive epistasis and testing major effects of detected QTLs at a multiple regression model. For most of traits, transgressive segregation was observed in both positive and negative directions. A total total of forty-nine QTLs with LOD ≥ 2.5 (LR ≥11.5) were identified. Explained genetic variance by these QTLs varied from 27.74 to 81.42% and maximum LOD for the QTL controlling seed plumpness was obtained on chromosome 3H (Qplum3H) with a LOD = 9.08. The largest single QTLs belonging to the quantity and quality of barley grains malt were located on chromosomes 1H, 2H, 3H, 4H and 7H. Seven additive × additive epistatic effects between identified QTLs were significant. The results revealed that water deficit compared with the location, had a significant role in the manifestation of malt quality traits. Meanwhile, in the studied haploids and their parents great variation was observed in terms of quantity and quality characteristics of barley malt. This variation can be exploited for different breeding purposes. In addition, identified stable and clustered QTLs could be used for qualitative and quantitative traits of barley malt in marker assisted selection (MAS). However, some detected markers can be identified as an informative marker for selection and increment of the concentration in the final malt extract and malt performance.

Eight tomato cultivars (GH1, GH12, Ajeet, Karina, Cluster 5, Manisha, Tolstoi and Dartom native) were screened for resistance against the root-knot nematode, Meloidogyne javanica, under controlled environmental conditions. In greenhouse experiment, tomato seedlings were inoculated with two J2s/g soil. Eight weeks after inoculation, the reactions of the cultivars were evaluated. Based on the nematode reproduction factors, the cultivars GH12 and Ajeet evaluated as moderately resistant and GH1 and Manisha as tolerant, whereas the other cultivars were susceptible to M. javanica. In molecular studies, eight pair of microsatellite (SSR) markers were used to find markers linked to resistance to M. javanica. Second allele of the primer Tom 55-56 was the only allele in moderately resistant cultivars, whereas the second allele of Tom 47-48 found only in susceptible cultivars. These alleles showed significant correlation with number of galls produced by the nematode. The correlation coeffivients of Tom 47-48 with susceptibility and Tom 55-56 with resistance were 0.732 and -0.732, respectively. The other alleles were not related to susceptibility or resistance.

In the present study, resistance of 29 potato clones to fusarium dry rot disease was compared with some commercial cultivars and a susceptible check cultivar Lady Roseta. Tubers of the potato clones and cultivars were artificially inocutate with aggressive isolates of Fusarium sambucinum and F. solani and maintained in a growth chamber at 16°C and 95% relative humidity for four weeks. The experiment was in factorial with two factors of Fusarium species and potato clones, using three replications. Disease index, infected area of tubers and sprouting rate were recorded for each treatment after four weeks. Based on the results of experiment, potato clones 397009, 39709713, 39708-10, 397097-2, 397007-16, 397074-3 and cultivar Aria having the lowest disease index (ranging from 168.52 to 228.25) and lowest tuber infected area, were considered as resistant, while clones 396124-97 × 396151-15 and 396151-29 with highest disease index and tuber infected area were susceptible. Fusarium species had an invert effect on tuber sprouting so that susceptible potato clones and cultivars had the least tuber sprouting rate.