نشریه نهال و بذر
سال سی و چهارم شماره 4 (زمستان 1397)

Yellow rust (stripe rust) caused by Puccinia striiformis f. sp. hordei is an important disease that threatens barley production in some areas of the world. Host resistance is the most economical strategy to manage barley stripe rust, and slow rusting resistance, a type of quantitative resistance, has been reported to be more durable than other type of resistance. Slow rusting parameters including final rust severity (FRS), apparent infection rate (r), relative area under disease progress curve (rAUDPC), and coefficient of infection (CI) were evaluated in a set of 41 barley promising lines together with susceptible control in 2016 and 2017 cropping seasons. This study was conducted in field plots at Ardabil Agricultural Research Station, Ardabil, Iran, under artificial infection conditions of race populations of Ardabil. Seedling reaction was also evaluated under field conditions. Results of evaluation for resistance parameters showed that lines; EDC-87-3, EC-90-4, EM-88-2, EM-88-5, EM-89-19 and susceptible check had the highest values of FRS, CI, r and rAUDPC, therefore, were considered as susceptible. Ten lines were resistant at seedling and adult plant stages, seven lines showed resistance at seedling, but had moderate reactions at adult plant stage. Thirteen lines (2, 5, 8, 10, 12, 14, 15, 19, 23, 29, 31, 38 and 39) were susceptible at the seedling stage and had intermediate (MR, M or MS) reactions at adult plant stage. Therefore, these lines with low level of different measured parameters were assumed to have gene(s) for varying degrees of slow rusting resistance or high temperature adult plant resistance (HTAPR). The remaining lines had low level of slow rusting resistance. Cluster analysis based on adult plant resistance parameters and seedling infection types revealed different groups which indicated considerable variation for different level of resistance among the barley promising lines examined in this study.

Indentification of genetic variation and grouping genotypes is very important for being used in research and breeding programs. In this study various quantitative and quality characteristics in 156 pomegranate (Punica granatum L.) genotypes in the National Pomegranate Research Station in Saveh, Iran, in 2015-16, using randomized complete block design with three replications. The results showed that fruit weight had the highest correlation with number of seed in 100 gram aril and aril weight. Stepwise regression analysis revealed that fruit width, number of seed in 100 gram aril and peel thickness had the highest contribution to fruit weight. Path analysis showed the highest and positive direct effect of fruit width, number of seed in 100 gram aril and peel thickness on fruit weight. Therefore, these are very important characteristics for selection. About 71.25 percent of variation among 16 measured characteristics was explained by six principal components. The first component included, fruit weight, width and length as well as aril weight, and had the most positive effect on quality characteristics such as: fruit juice and maturity index. Anthocyanin had the most negative effect. Therefore, these characteristics play major role on variation among pomegranate genotypes. Factor analysis revealed three important factors that were called; fruit components, fruit color and fruit flavor. Therefore, characteristics related to these factors are in the first priority for selection. Genotypes were clustered in 11 groups using Ward’s method. It is predictable that crossing between genotypes from discrete groups could led to considerable variation among progenies.

In this research, morphological, leaf chlorophyll and its variations, biochemical traits related to the fruit quality and sclereid cell cluster characteristics were evaluated in 15 introductions of European pear cultivars. Morphological characteristics based on 68 traits of the national descriptors for distinctness, uniformity and stability as well as chlorophyll were evaluated during growing period. Morphological evaluation revealed distinctness in tree, branch, leaf, flower and fruit traits. Among the evaluated traits, color of branches, length : width ratio of leaf, position of petal margins, length : diameter ratio, position of largest diameter and color of fruit skin, and the characteristics of fruit stalk were highly distinctive. Length : width ratio of leaf, ranged from <1.4, 1.4-1.5, 1.5-1.6, 1.6-1.7 and >1.7 in very narrow to very broad leaves. For length : diameter ratio of fruits ranged from <1.0, 1.0-1.2, 1.2-1.4, 1.4-1.6 and >1.6 indicated extremely wide to extremely narrow fruits. In addition, quantitative traits showed that these traits were mostly consistent with the control cultivars of the UPOV descriptor, however, low stability was observed in some traits such as blooming time. Leaf chlorophyll content changes showed varied patterns, but mostly increased in the beginning of summer and decreased toward leaf fall. Meanwhile, the highest chlorophyll indices were found in Alvert, Beurre Diel and Doyenne du Comice cultivars. Based on the results of this study, Packhams Triumph, Doyenne du Comice and Bulghar No. 2 were identified as superior cultivars.

To evaluate agronomic characteristics, seed yield and yield components of faba bean (Vicia faba L.) varieties in Sistan region, an experiment was conducted using randomized complete block design with three replications in 2013 and 2014 in agricultural research station of Zahak, Sistan, Iran. Combined analysis of variance showed significant differences (P < 0.01) among varieties for all studied traits. Seed yield, green pod yield and seed protein yield were higher in the second year among the cultivars. The highest seed yield (1947 kg ha-1), and green pod yield (20557 kg ha-1) belonged to Saraziri cultivar. The highest (33%) protein content belonged to Shakhbozee cultivar. Correlation analysis showed significant positive relationship between seed yield, pod length, number of pod per plant, green pod weight plant-1, green pod yield and seed protein yield. Cluster analysis grouped faba bean varities into two main groups of high yielding and lower yielding cultivars. Shakhbozi and Saraziri had the highest seed and protein yields. Therefore, considering results of this research and important economic traits in faba bean (seed yield and green pods yield), Saraziri and Shakhbozi were identified as superior cultivars and suitable for Sistan conditions.

This experiment was conducted to investigate heritability, combining ability and genetic control of important traits of greenhouse cucumber inbred lines in 2015-2016. The genetic materials used in this experiment were 52 hybrids from 10 male and 27 female cucumber inberd lines which were examined in two separate experiments. These experiments were carried out as North Carolina Design I using randomized complete block design with three replications. The results showed that male parents 1, 2 and 13 had the highest values of vegetative traits in both experiments. Estimation of genetic parameters for vegetative traits also indicated low levels of additive variance and narrow-sense heritability. The highest total number of fruits in the first experiment was observed in male parent number 7. Regarding fruit yield related traits, male lines number 7 and 15 in the first experiment had higher fruit yield. The results of second experiment showed that the longer fruit production duration and higher number of fruit per node belonged to male parents 10 and 3, respectively. There was no significant differences for other fruit related traits. Estimation of genetic parameters showed that in many of traits associated with fruit such as fruit diameter, fruit firmness, fruit number and yield, the additive variance and narrow-sense heritability were high, therefore, it is possible to select successfully for these traits. In general, male inbred lines number 7, 13, 15, and 24 contributed to increasing of fruit-related traits and fruit yield in progenies.

Sweet cherry is one the important fruits in temperate region. Short duration of fruit production necessitates development and release of new early maturity sweet cherry cultivars. Selection in germplasm for new cultivars is practiced in fruit trees breeding programs. This research was carried out to evaluate quantitative and qualitative characteristics of five cherry cultivars: Adli, Belmarca, Pish Ras, Siah Mashhad, Siah Qazvin and Mashhad-84 promissing genotype, in Golmakan agricultural research station, Mashhad, Iran, in 2017-2018. The results of pollination showed that Mashhad- 84 promissing genotype is self- incpmpatible and cv. Dovomras, Stella and Haji Yousefi were identified as suitable pollinizers for it. Flowering in Mashhad-84 promissing genotype began on April 8 and full bloom completed in April 12. The duration of fruit ripening varied greatly aomong genotypes. Average fruit weight of Mashhad-84 promising genotype was 6.06 grams which was greater than average fruit weight of Adli (4.06 g), Pish Ras (4.04 g), and Belmarca (3.05 g). Early maturity cultivars usually have smaller fruit size, therefore, higher average fruit weight of Mashhad- 84 promising genotype is one of its advantage which will enhance its economic value and marketability.