نشریه نهال و بذر
سال سی و یکم شماره 3 (پاییز 1394)

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.

This study was carried out to investigate the genetic structure of the 36 maize hybrids established from eighteen female lines and two male testers according to line × tester method under normal irrigation and drought stress conditions. Two separate experiments، normal irrigation and drought stress at grain filling stage were performed in Moghan for two years، using a RBCD with three replications. The results showed that the effect of gene action could be both non-additive and additive in the expression of grain yield under both conditions. However، GCA/SCA variance ratio revealed that non-additive genetic variance was more important for grain yield than additive variance. Analysis of general combining ability indicated that the variation of combining ability of lines in non-water stress condition was higher than that in water stress condition. The reactions of general combining ability of lines in both conditions were not similar. Lines L8، L11 and L17 in normal irrigation and lines L15، L16 and L17 in stress condition showed better general combining abilities for grain yield. The K3653/2 tester showed better general combining abilities for grain yield in both conditions. The crosses such as L1×T1، L4×T1 and L8×T1 in normal irrigation condition and L9×T2 in drought stress condition showed better specific combining abilities for grain yield.

This research was undertaken to study genetic diversity among 25 wheat genotypes (21 durum wheat breeding lines، two durum wheat landraces Zardak and Gerdish، Saji durum wheat cultivar and Sardari bread wheat landrace) based on agro-physiological traits under rainfed conditions in research farm of Dryland Agricultural Research Sub-Institute (Sararood station) during 2011-12 cropping season. The genotypes were also investigated based on molecular markers in biotechnology laboratory of Islamic Azad University، Kermanshah، Iran. The results of ANOVA and mean comparisons indicated significant differences among genotypes for most of the studied traits. Genotypes No. 11 (18E-BCRIS/BICUM) and 10 (18E-BCB509CHILE/SOMAT-3. 1) had the highest and lowest yield productivity، respectively. Cluster and discriminate analyses، based on the traits entered in stepwise regression analysis، classified the genotypes in four groups. Evaluation of genetic diversity by eleven ISSR primers indicated that the most polymorphic information content (PIC) belonged to primer No. 6 (PIC = 0. 36) and the least one belonged to primers No. 1 and 5 (PIC = 0. 22). Cluster analysis using UPGMA and based on dice similarity coefficient (DSC) classified the genotypes in three major groups، where the genotype No. 25 (Sardari bread wheat) was classified in a distinct group. Based on DSC، the genotypes No. 9 (18E- CAMAYO) and 10 had the highest similarity coefficient and the least one was observed between the genotypes No. 1 (18E-SORA/2*PLATA) and 25 (Sardari).

The soil samples containing the pathogen، Plasmopara halstedii، were collected، refreshed and mass-produced on susceptible cultivar Record، using whole seedling immersion method. The isolates were inoculated on standard differential lines to investigate the physiological races. Using the dominant race (race 100) of the pathogen in sunflower planting areas، 77 new Iranian sunflower genotypes including hybrids، restorer lines، CMS lines and individuals were evaluated against the disease under controlled conditions. Fifteen days post inoculation، the treated plants were evaluated based on six qualitative disease characteristics including damping-off، sporulation on cotyledons، sporulation on leaves and cotyledons، stunt، leaf mosaic or chlorosis and deformation. They were then converted to quantitative means based on their importance in disease development. Finally the average of the means as disease severity index (DSI) was used for evaluations. Based on the results، 64 genotypes were categorized as resistant and the rest were identified as moderately resistant، moderately susceptible، susceptible، and highly susceptible.

Apple (Malus domestica Brokh.) as other fruit trees of Rosaceae family is self-incompatible (SI). The apple SI system is controlled by a multi allelic single locus; S-locus. In this study، the results of orchard based phenotyping of 25 apple genotypes were compared with the results of on-going S-allele genotyping of them. A more common consensus primer pair، FTQQYQ and FI (D/N) CP (H/R) was able to amplify the S alleles fragments of all samples. Then، using eight pairs of allele specific primers were able to detect S1، S2، S3 and S4 with certain indicating the rather high frequency of these S-alleles in the studied apples. Narsib-e-Mashad، Ardebil2 and also، Englisi-e-Shiraz with three detected S-alleles could be considered as triploids، probably. These primers could not produce any bands for half of the samples leading to apply the remained list of specific primers. Despite of self-incompatibility of apples، some of the cultivars including Payize-e-Mashad، Sheikh Ahmad، Morabbayi، IRI1 and IRI4 showed auto fertility. The genotype IRI6 with highest percentage of fruit set was considerable. According to the results of this research، the PCR based techniques in apple S-genotyping is more useful to recognize cross-compability situation of genotypes.

To evaluate the genotype environmental interaction and determine seed yield stability and adaptability of dryland promising lentil genotypes، this study was conducted during three cropping seasons (2011-2013) in three regions of cold dryland areas including Zanjan، Maragheh and Ardebil. Experiments consisted of 12 promising lentil genotypes with a check cultivar arranged in randomized complete blocks design with four replications. Combined analysis of variance was done for three years in three locations. Lin and Binns parameter، coefficient of variation of seed yield and ranking method were used for determination of the stable genotypes. Results showed that year، location، genotype and interactions of year × location، location × genotype، year × genotype and year × location × genotype were significant (p<0. 001). The highest and least seed were obtained in Ardebil (714. 36 kgha-1) and Zanjan (298. 78 kgha-1) stations، respectively. Genotypes No. 1 (Flip96-59L)، 3 (Flip05-58L) and 6 (Flip04-31L) with seed yield of 520. 87، 505. 90 and 504. 17 kgha-1، respectively were better than check and other genotypes. Regarding to the seed yield and other agronomic traits، genotype No. 1 had the lowest R and SDR and had higher seed yield (stable). Genotype No. 6 had the lowest environmental variance، CV and R and genotype No. 3 had the lowest SDR (stable).

In this study، resistance of 230 wheat elite lines and commercial cultivars was evaluated to Mycosphaerella graminicola، the fungal pathogen of septoria leaf blotch، at seedling and adult plant stages (in greenhouse at Cereal Pathology Unit، Seed and Plant Improvement Institute، Karaj، and in experimental fields of Gorgan Research Station، respectively). The first leaves of seedlings of wheat genotypes were separately inoculated with three high virulent isolates of the pathogen. Seedling resistance was visually assessed based on percentages of leaf necrotic area and pycnidial coverage at 21 days post inoculation. Results showed that 49، 25 and 34% of genotypes were resistant to the pathotypes 87001، 87051 and 88005، respectively، whereas the rest showed various levels of susceptibility. The wheat cultivar Darya and the lines S-87-1، S-87-10، S-87-15، S-87-16، S-87-17، S-87-18، S-87-20، S-87-22، C-86-1، C-86-5، C-85-4، C-85-6، C-85-9، C-81-10، C-80-4، N-86-12، N-83-3 and M-85-16 were resistant to all three isolates. Evaluation of adult plant resistance scored by 00-99 modified scale، showed the resistance reaction for 39% of the genotypes. Over 50% of plant materials were susceptible to the pathogen isolates at seedling and adult plant stages. Wheat genotypes with acceptable levels of resistance could be used as sources of resistance in wheat breeding programs.

Rusts are important diseases of wheat in case of economy and distribution in the world and use of resistant cultivars is the best method to control them. In the present study، reaction of 124 Iranian wheat genotypes were evaluated against five dominant isolates of each yellow rust (YR)، leaf rust (LR) and stem rust (SR) at seedling stage. All genotypes were also evaluated at adult plant stage in field and area under disease progress curve (AUDPC) was calculated for them. The results showed that from 124 genotypes، 35، 24 and 7 genotypes were resistant to all isolates of YR، LR and Sr respectively. Line N-87-13 was resistant to all three rusts. Line M-87-18 that carries Lr24/Sr24 genes showed resistance reaction to leaf and stem rust isolates. Nine genotypes DM-84-3، DM-79-2، M-86-5، N-87-13، Arta، Dena، Bahar، Sepahan and Sivand were resistant to all YR and LR isolates. Five genotypes N-86-4، N-87-4، N-87-13، WS-86-8 and SS-85-20 showed resistance reaction to all isolates of YR and SR. Totally، 28% of genotypes were resistant to YR، 19% to LR and 5% to SR isolates. Twenty-nine genotypes were known carrying resistance gene Lr34 showed low levels of AUDPD in field. Based on the reaction of cultivar Aflak and line M-85-7 to LR both at seedling and adult plant stages، it seems that they may carry other adult plant resistance gene (s) in addition to Lr34.

One of the growth limiting factors of onion plants is root and basal plate rot disease، caused by Fusarium oxysporum f. sp. cepae. In this research، eight Iranian onion genotypes، Azarshahr Red، Ghom White، Herssin، Isfahan Dorcheh، Kashan White، Nishabour Ishaghabad، Yazd Abarkoh، Zanjan Gholigheseh and two commercial genotypes، Texas Erly Grano and Yellow Sweet Spanish were investigated. Genotypes were first divided in to resistant، tolerant and susceptible groups depends on disease factors. The root anatomical components including epidermis size، derma parenchyma (size and layer numbers)، endodermis size، pericycle size، different xylem sizes، Phloem size، central cylinder size، and sizes of sclerenchyma layer of root cortex were also assessed in genotypes. The results indicated that some of these anatomical components were different among onion genotypes. There was a direct and high correlation between some of these anatomical components and resistance of onion genotypes to root and basal plate rot disease. Layer numbers of derma parenchyma had the most important and significant role in the resistance level of onion genotypes. Resistant genotypes such as Kashan White and Ghom White had the maximum layer number of derma parenchyma but susceptible genotypes such as Hersssin and Zanjan Gholighese had the minimum layer number.