نشریه نهال و بذر
سال سی و سوم شماره 4 (زمستان 1396)

To evaluate yield and some quantitative and qualitative characteristics of tomato cultivars in Jiroft region and to determine suitable cultivar for this region, thirteen tomato cultivars were evaluated in an experiment using randomized complete block design (RCBD) with three replications during 2013-14. Cultivars consisted of Sun Seed, Rio Grande, Eden F1, Yagi, Kimia, Superchef, Calj N3, Yaghoot, Titan F1, Italian CH, Falat Ch, Falat Chef and Primo. In this study, traits of fruit yield, plant height, number of shoot and leaves per plant, days to flowering and harvest, fruit weight, length and diameter of fruit, total soluble solids (TSS), titratable acidity (TA) and vitamin C were recorded. Results of analysis of variance showed that the effect of cultivar on all traits was significant. Cultivars Eden and Kimia had the highest yield (61.62 and 58.78 ton ha-1, respectively). The results of evaluations showed generally that cultivar Kimia had better quantitative and qualitative characteristics and were determined as suitable cultivar for Jiroft region.

To study the resistance to powdery mildew and determine the resistance genes in Iranian germplasm of Hordeum spontaneum, a total of 29 genotypes belonging to wild barley collection of National Plant Gene Bank of Iran were investigated. For this purpose, the isolates of the causal agent of the disease were collected form infected fields of Karaj, Sari and Zarghan. The isolates were inoculated on seedlings of susceptible variety 'Afzal' and propagated as single clones. Five different pathotypes were distinguished by using 19 near isogenic lines. Evaluation of resistance of genotypes was performed by the pathotypes in greenhouse at seedling stage. The reaction of differential lines indicated that the isolate Karaj2 had higher pathogenisity than other isolates. The isolates lacked virulence factor for Mlal+Ml(A12), Mla3, Mla9, Mla13+Ml(Ru3) and mlo5 resistance genes. Hence, these genes were identified as having effective resistance in all three regions. The relationship among isolates was studied through biplot of multi-dimensional scaling method based on dissimilarity matrix. Among the studied genotypes, only genotype 314 was resistant to all isolates. The reaction patterns of genotypes 434, 1006, 451, 1040, 495 and 555 to the isolates were not consistent with any those of the differential lines indicating the probable presence of gene(s) different from those existing in the lines. The total results of this research demonstrated the existence of resistance sources to powdery mildew in Iranian germplasm of H. spontaneum and possibility of finding new resistance gene(s).

To evaluate the quantitative and qualitative characteristics of eight promising clones and three commercial cultivars of potato, an experiment was conducted based on a randomized complete blocks design (RCBD) with four replications in five regions (Karaj, Ardabil, Mashhad, Esfahan and Hamedan) during 2013-14. In this study, traits of average tuber weight, number and weight of tuber per plant, tuber yield, plant height, number of main stem per plant, tuber shape, eye depth, color of tuber skin and flesh, growth period, tuber hollow heart and tuber inner ring were measured. Results of combined analysis of variance showed that the effects of region, region × year, genotype, region × genotype and region × year × genotype on tuber yield were significant. Results of bi-plot analysis showed that clones 5 (397031-16), 11 (397045-13) and 9 (397009-8) had higher tuber yield and stability. These clones had cream, light yellow and cream tuber flesh, yellow, yellow and yellow tuber skin, round oval, round oval and round tuber shape and shallow, medium and medium eye depth, respectively, and the tuber hollow heart and inner ring were very little in them. The clones 11 and 5 had a high tuber dry matter (22.99 and 22.27, respectively). Overall, based on tuber yield stability and quantitative and qualitative characteristics, the clones 5, 9 and 11 were selected.

Cytoplasmic-genetic male sterility is widely used for production of sunflower hybrid seeds. In sunflower, an ORF, ORFH522, presented at 3′ end of atpA gene cause male sterile phenotype. This investigation was carried out to find the molecular marker for PET1 cytoplasmic-genetic male sterility system in sunflower. To this end, five male sterile, 24 maintainer and 32 restorer lines were used as genetic materials. The gene sequences for both male sterile and male fertile were extracted from NCBI and upon their alignment, a primer pair was designed based on their different regions. The primer pair amplified a fragment of 182 bp in cytoplasmic male sterile lines, while no amplification in male fertile ones was observed; Thus, the primer is considered as a marker for male sterile cytoplasm. Also it was confirmed that all restorer lines have male sterile cytoplasm. Thus, the primer can be used efficiently in breeding programs of sunflower either in transferring male sterile cytoplasm to elite lines, or in restorer line production and purification.

To identify the superior lime genotypes in Southern region of Iran, fruit characteristics of 35 genotypes were investigated during 2014-15. In this study, traits of peel thickness, weight, length and diameter of fruit, total soluble solids (TSS), seed number, volume and density of fruit, juice percent, juice pH, vitamin C and titratable acidity were measured. The results of descriptive statistics showed that the highest coefficient of variations were related to fruit volume, fruit density, seed number and fruit weight (83, 77, 75 and 61 percent, respectively), which showed there is a diversity between genotypes. Furthermore, cluster analysis of Ward's minimum-variance method, divided studied genotypes into three groups. The first group with lower peel thickness, the higher juice percent and higher acidity was categorized into superior group. Overall, The results showed that fruit of some studied lime genotypes had high quantitative and qualitative characteristics and depending on the purpose (in processing or food industry), it could be used to improve various traits for breeding programs.

In this study, the genetic diversity of 90 accessions from 12 populations of Triticum boeoticum was evaluated using randomized complete block design with two replications. These populations were collected from the Western and Northwestern of Iran. Each experimental unit was 0.5 m long and consisted of one row spaced 20 cm apart. During the growing season, 15 agro-morphological traits were evaluated. Analysis of variance revealed significant differences among the accessions at 1% level of probability. Grain yield had a significant correlation with all of the traits except harvest index. The highest correlation of grain yield was observed with biomass and number of fertile and total tillers. Multiple regression showed that the number of fertile tillers, leaf length, leaf width and grain weight in the main spike had the highest direct effect on the grain yield. Factor analysis resulted in three factors that explained 77.38% of the total variance. Factors were named as 1) main spike and leaf, 2) yield and its components and 3) phenological characters. Canonical correlation indicated the latitude as the most effective geographical factor and leaf width, length of main spike, leaf length and number of spikelets were mostly affected by the geographical factors. Overall, a high diversity was observed for all of the studied traits in the surveyed accessions. Kordestan, West Azarbayjan and Kermanshah provinces were recognized as the diverse geographical regions.

Breeding for resistance to damping off is one of the main aims in sesame breeding scheme. Since the most important causal agents of damping off are soil- borne fungi, using resistant cultivars is the best strategy to control this disease. The fungi, Macrophomina phaseolina (causing charcoal rot) and Fusarium oxysporum f.sp. sesami causing root (causing crown and stem rot of sesame) are the most important causal agents of damping off in sesame in Iran. In this research for screening of sesame germplasm to damping off agents, 81 native and improved genotypes of sesame were cultivated in a farm infested by infected plant debris. The experiment was conducted as simple lattice with two replications during 2002-2004 growing seasons at the Research Farm of Seed and Plant Improvement Institute, Karaj, Iran. The results showed that four genotypes of Moghan 17, Moghan 19, Moghan 3 and Iraqi 2 had the highest level of resistance to damping off in field condition. Sixteen genotypes grouped as moderately resistant, 15 genotypes as moderately susceptible and the rest grouped as susceptible or highly susceptible ones.