نشریه نهال و بذر
سال سی‌ام شماره 4 (زمستان 1393)

Extensive and deep root system play important role in wheat drought tolerance and yield in water deficient condition. Nevertheless، a little is known about root structure genetic. In this research، a half diallel mating design was generated from crosses between eight bread wheat cultivars to study the genetic of root system. Parents and F1 progenies were planted in cyclic stress condition in a randomized complete block design with four replications and root length، root weight، root number، shoot weight، root to shoot ratio، grain yield، plant height and peduncle height were measured. Results showed that additive and dominant effects were significant for all traits. However، additive-dominant model was not adequate for root number. Non-additive variation was more important in genotypic disparity of root length and root to shoot ratio. Consequently، bulk، single seed descent and double-haploid methods are recommended in breeding program for these traits. Additive variation had imperative effect on genotypic variation of root weight and plant height. Thus، despite of mentioned breeding methods، pedigree and back-cross are recommended for these traits. Cultivar Roushan had an appropriate root system and high general combining ability for the root system traits. Accordingly، in breeding programs for developing root system، Roushan is recommended as one of the mating parents.

In order to evaluate adaptation of six Greek olive cultivars (Conservolia، Thiaki، Chalkidikis، Megaron، Agouromanako and Patrini)، an experiment was conducted in a randomized complete block design in Dallaho and Taroum Olive Research Stations during 2006-2010. Trees were planted with a 6×6m distance in 2005. Vegetative and reproductive traits of olive trees were measured. Variance analysis results for different characteristics showed that tree height، canopy diameter and trunk cross sectional area differed significantly at 1% probability level in both locations. Inflorescence number per shoot، flower number per inflorescence، perfect flower percent and final fruit set also differed significantly under Sarpole Zehab and Tarrom environmental conditions. Fruit weight was between 0. 99 (for Thiaki) to 5. 7 g (for Conservolia) in Sarpole Zehab and 1. 81 (for Thiaki) to 10. 7 g (for Chalkidikis) in Taroum. Differences among cultivars for fruit yield were significant، so that fruit yield of all cultivars was higher at Taroum compared to Sarpole Zehab. Oil percent in dry matter was higher than 35% only in consevalia and Chalkidikis cultivars in Sarpole Zehab while it was higher than 48% for all cultivars in Taroum. In general، all cultivars showed better performance in Taroum condition compared to Sarpole Zehab. Chalkidikis and Thiaki were suitable cultivars for dual and oil production، respectively in Taroum.

Following the occurrence of spring frost in Khorramdarreh Agro- Industry farm in Zanjan province، Iran، during 2010، fifteen walnut promising genotypes showing frost escape response were selected. Tree، fruit and kernel characteristics of selected genotypes were assayed according IPGRI descriptors. Meanwhile، the genetic diversity، distinction and classification were also assessed using microsatellite markers. The 13 SSR primers produced 37 bands across 15 genotypes، with an average of 2. 84 polymorphic fragments per primer. The number of amplified bands varied from 2 to 4 with size of amplicons ranging from 209 to 308 bp. Two loci WGA276 and WGA071 were the highest and lowest distinguishable among genotypes، respectively. Cluster analysis based on both morphological and molecular data clarified the relatively large genetic distance among genotypes. However، clustering of genotypes within the genotypes showed low similarity when morphological and molecular derived dendrograms were compared. Although all evaluated genotypes were appropriate referring to leafing late and producing fruitful buds in terminal and lateral shoots، however، genotype T36R67 generally showed high quality characteristics and is good candidate for further complementary assessments and using in breeding programs.

To identify the barley yellow rust pathotypes، yellow rust samples of were collected from barely، wild barley (Hordeum morinum) and wheat in different provinces of Iran. Isolates were identified as P. striiformis f. sp. hordei or P. striiformis f. sp. tritici based on virulence on barley or wheat differential seedlings، respectively. Virulence factors and pathotypes of barley yellow rust were determined based on avirulence/virulence formula. Totally، ten pathotypes were identified in this study، of which seven were new pathotypes for the world. Some of pathotypes may be the result of hybridization between the two formae speciales، since they exhibited virulence on a number of wheat differentials and triticale in addition to barley differentials. The pathotypes PSH-87 and PSH-84 with six virulence factors had the widest virulence spectrum and two pathotypes PSH-51 and PSH-85 with three virulence factors had narrow virulence spectrum. None of the pathotypes had virulence on resistance genes rpsEm1 and rpsEm2 and only one pathotype had virulence on each of resistance genes Rps4 (Yr4)، rpsHF، rpsVa1، rpsVa2 and Rps1. c. The highest virulence frequency was determined for genes rpsHi1، rpsHi2 (0. 83%) and rps2 (0. 67%). The genes which were effective against all or majority of pathotypes can be used as resistance sources in breeding programme for cotrolling barley yellow rust.

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.

Apricot has specific role in fruit production industry of Iran. Asian and Iranian-Caucasian apricots show the high level of S-RNase-based self-incompatibility results in low bearing and yield of trees. In order to determine self-incompatibility in some apricot cultivars and genotypes، an artificial field pollination test and molecular experiments using specific primers were conducted. Pistil length، ovary thickness and pollen germination percentage were determined. Results of pollen germination percentage showed no male-sterility in these genotypes. The cv. Shahroodi and genotype C had the highest percentage of fruit set as well as pistil length and ovary thickness. Considering the results of field pollination test and molecular experiments، cvs. Badami، Shahroodi، Shekarpareh and Daneshkadeh as well as genotype C were self-incompatible and only genotype D was self-compatible. The cvs. Badami، Daneshkade and genotype C were cross-incompatible.

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.

Evaluation of genotype × environment interaction with the objective of selection of the superior genotypes is the most important part of breeding programs. In this study، twelve promising winter rapeseed lines with one check cultivar (Okapi) was investigated for the stability and grouping using Lin and Butler cluster analysis methods. Experiments were performed in randomized complete block design with three replications at Karaj، Kermanshah، Bojnurd، Hamedan، Isfahan، and Arak research stations during two cropping seasons (2010-12). The data of Bojnurd and Arak were omitted because of the high error mean squres shown by Bartlet''s statistic. Combined analysis of variance performed by assuming environments (years and locations) as random and genotypes as fixed factors. The results of combined analysis showed that the interaction effects of year×location and year × location × genotypes were significant at 1% and 5% level of probability، respectively. The results of clustering using the first model showed that promising lines No. L137، L201 and L119 were the most stable lines. The second model divided lines in to two groups. In the first group، the same lines with the maximum regression coefficients were recognized as stable genotypes for favorable environment. In the second group، line L63 with the minimum regression coefficient was suitable for unfavorable environments.

To investigate important physiological and agronomic traits effective under drought conditions، their relationship with grain yield and to study drought tolerance and susceptibility indices in 169 barley recombinant inbred lines population of Arigashar/Igri، an experiment was carried out using alpha lattice design with two replications during 2011 to 2013 in Yazd and Birjand Research Stations under non - stress and drought stress conditions. During cropping seasons، lines were evaluated for physiological and agronomic traits. Combined analysis of variance of studied traits under two conditions showed significant differences among environments، genotypes and genotype × environment. Under drought stress conditions، harvest index (r = 0. 753**)، biological yield (r = 0. 572**)، canopy temperature (r = -0. 522**)، leaf relative water content (r = 0. 385**) and thousand kernel weight (r = 0. 339**) and under non-stress conditions، biological yield (r = 0. 572**) and harvest index (r = 0. 753**) had significant correlations with grain yield. Among physiological and agronomic traits which had high correlation with grain yield under drought stress conditions، canopy temperature can be utilized as an important selection criteria to identify drought tolerance genotype، because of its easy measurement in all breeding program stages. Based on grain yield under drought and non-stress conditions (Ys and Yp) and tolerance and susceptibility indices (SSI، TOL، MP، GMP، STI and Harm)، liens were classified in to four distinguished groups: a)high - yielding and drought tolerant، b) high - yielding and drought susceptible، c) semi tolerant and d) low - yielding and drought susceptible.

Interspecific hybridization occurs among Cucurbia species it is commonly used for grafting، yield increasing and production of pest resistant rootstocks. In the present research probability of interspecies hybrid generation among seven lines of Cucurbita pepo (P1، P4، P5، P6، P10، P22، P25) and six lines of Cucurbita moschata (MO3، MO5، MO6، MO9، MO11، MO12) were investigated. After crossing of fruit set، fruit set with normal seed and viability were recorded. 25. 66% and 19. 41% of total fruit set and fruit set with normal seed were recorded when C. moschata were used as female parent while 19. 44% and 13. 88% and 13. 88% of total fruit set and fruit set with normal seed when C. pepo were used as female parent. The highest total fruit set were obtained when MO11 and MO9 were used as female parent while the highest fruit set with normal seed were obtained MO6 and MO9 were used as female parent in different interspecies crosses. Using line O5 as male parent lead ti the highest seed viability in different interspecies crosses. The highest total fruit set and fruit set normal seed were obtained when P5 were used as female parent in different interspecies crosses. Results showed that C. moschata as female parent is more successful C. pepo. However hybrid vigor and heterosis have to be tested in future.

Jujube (Ziziphus jujube) belongs to Rhamnaceae family. It is considered not only for medicinal usage، but also is cultivated as an ornamental plant due to its beautiful leaves and trunk. The first step in a plant breeding program is to collect native genotypes of a plant in a region and evaluate them for selection of superior genotypes. Jujube is grown naturally in some areas of Iran، as well as in Golestan province. In the present study ten ecotypes of jujube grown in this province were collected from different areas and their phonological and morphological traits as well as some fruit characteristics and qualitative factors such as vitamin C، pH and total soluble solids (SST) were evaluated during years 2009 to 2011. Different vegetative، morphogic and fruit traits such as flowering thme، branch angle. Length of one year old branch، number of thorn on branch، fruit weight، length and width، stone weight and length، flesh weight، flesh/stone ratio، vitamin C، TSS and fruit pH were measured based on jujube descry. The results showed a high diversity for different traits among the ecotypes. The results also showed that vegetative traits were affected considerably by geographical and climatical factors. Ecotypes prown in west of the province where humidity is high، showed characteristics different from those grown in eastern regions. Fruit characteristics were also influenced by environmental factors.