SEED AND PLANT IMPROVEMENT JOURNAL
Year:2013 | Volume:29-1 | Issue:2|Papers Count:14

Olive is a drought tolerant plant and there is considerable genetic variation for drought tolerance among olive cultivars. In order to evaluate genetic variation of olive, an investigation was carried out in factorial experiment based on completely randomized design with three replications on one-year-old of twelve olive cultivars. Drought stress treatments included control, mild stress and severe stress (90, 55 and 35% of FC water, respectively). Results showed that drought stress reduced the relative water content and stomatal conductance in all cultivars. Dry biomass of root/shoot ratio, was increased by drought stress. Stress Tolerance Index (STI), Mean Productivity (MP), Geometric Mean Productivity (GMP), and Harmonic Mean (HARM) had the most correlation with relative growth percent in control and severe stress conditions, thus they were identified as the best indices for screening drought tolerant in seedlings of olive cultivars. Based on these indices and principal component analysis, cvs. Mission, Konservolia and Sevillano were detected as high tolerant cultivars to drought stress. Results of drough stress tolerance evaluation by drought stress indices obtained in the present study were highly consistent with other studies on traits of these cultivars.

This study was conducted to evaluate genetic diversity in eight native populations of Iranian cucumber including Birjand, Roudbar, Gorgan, Kashan, Yazd, Taft, Sanandaj, and Isfahan in comparison with Super Daminus hybrid as control in a randomized complete block design with three replications for two years (2007 and 2008) in two regions (Varamin and Isfahan). Studied traits were days to flowering, number of fertile flowers, the ratio of female/ male flowers, number of branches, days to first harvest, average number of fruits per plant, weight of fruits per plant, average fruits length per population, the ratio of three first harvest / total yield and average yield per plant. The results indicated the existence of high genetic differences between local populations and Super Daminus hybrid. Based on cluster analysis, populations were classified in three groups. According to clusters segregation in the highest difference level, Super Daminus had the highest difference with other populations showing that this hybrid has a genetic different from other populations. After control cultivar, Yazd and Taft populations had the most differences with other populations, respectively. Maximum similarity was observed between Isfahan and Kashan populations and amang Gorgan, Roudbar and Sanandaj populations as well. Furthermore, Isfahan and Kashan populations were similar to Birjand population and three of them were somewhat similar to Gorgan, Roudbar and Sanandaj populations.

In order to choose climate-compatible pistachio cultivars in Khorasan, this research was carried out in Pistachio Research Station in Feizabad on 12 pistachio cultivars namely Badami-e- sefid, Pesteh-e-ghermez, Barg seyah, Daneshmandi, Pesteh-e-garmeh, Akbari, Kalehghouchi, Owhadi, Khanjari, Abasali, Shahpasand and Momtaz, based on a randomized complete block design with three replications during three years (2006-2008). The results showed that the factors year, treatment (cultivars) and their interaction effects were significant (p<0.01) for all characteristics. The highest number of flower bud per shoot was on Barg-seyah and Akbari and the lowest on Pesteh-e-garmeh cultivars. The most early and late flowering cultivars were Pesteh-e-garmeh and Akbari respectively, which had 12 days difference at the biggining of flowering. There was significant difference between Badami-e- sefid with 20 nuts per cluster and Abasali with 7 nuts. The highest and the lowest percentage of blank pistachio were 24 and 7.4 on Badami-e-sefid and Abasali, respectively. Pesteh-e-garmeh and Pesteh-e-ghermez with 32 and 30 nuts had the smallest and the biggest nuts per ounce. Shahpasand (native of Damghan region) showed the highest percentage of early splitting (14.8%) and had significant difference (p<0.01) with other cultivars. In addition, Momtaz, Shahpasand, Khanjari and Owhadi did not show suitable compatibility, but, Badami-e-sefid, Akbari and Pesteh-e-garmeh showed more compatibility than the other cultivars.

In order to evaluate morpho-physiological traits of advanced barley lines under drought stress and supplementary irrigation and the relationship of these traits with yield, twelve lines were studied in Maragheh Dryland Agricultural Research Station during 2009- 2010 in RCBD with three replications. Different morpho-physiological traits were assessed during growth period. Under drought stress, results showed considerable differences among lines for days to heading, number of seeds in main spike, number of unfertile spikelet, spike length and harvest index. Under supplementary irrigation, the lines differed for growth vigor, days to heading, 1000 kernel weight, fertile spikelet, spike length and weight, number and weight of seeds in spike, harvest index and grain yield. Number of spike/m2 (r=0.68**) and germination percentage (r=0.65**) showed significant and positive correlation with grain yield under drought stress. Under supplementary irrigation, plant height (r=0.7*) and number of seeds in main spike (r=0.59*) had positive correlation with grain yield. Drought tolerance indices such as STI, MP and GMP had highest correlation with grain yield under drought condition and SSI, TOL, STI, MP and GMP had the highest correlation with grain yield in terminal supplementary irrigation. Line No.9 (TOKAK//STEPTO/ANTARES) with 2694 kgha-1 grain yield and high 1000 kernel weight was determined as a drought tolerance genotype.

To produce new hybrids and study the combining ability of new sunflower inbred lines, 60 F1 hybrids derived from crossing between 30 inbred lines and 2 testers along with Azargol, SHF81-85, SHF81-90 and Cms1052/1*14 as checks were evaluated using simple lattice design with two replications in Agricultural Research Station of Islamabad-e-Gharb in 2011. Analysis of variance showed that genotypes were significantly different for all recorded traits except days to end of flowering and seed oil content. Hybrids B86-353.1AF81-196, B86-284.1AF81-196 and B86-345.1AF81-196 had the highest seed yield (5583, 5331 and 5235 kgha-1, respectively). Combining ability analysis using design II of Comstock and Robinson showed that general combining ability of inbred lines and testers for seed yield was significant at 1% level. Inbred lines B86-353, B86-284 and B86-345 had the highest general combining ability for seed yield, whereas inbred lines B86-373.2 and B86-382.2 had the highest negative combining ability for days to maturity. Specific combining ability effect was significant for some agronomic traits such as seed yield, head diameter, plant height and days to maturity. The highest specific combining ability for seed yield belonged to hybrids B86-300.2AF81-112 and B86-346.2AF81-112. Hybrid B86-287.1AF81-196 had the highest negative specific combining ability for days to maturity.

In this research, relative resistance of leaf and shoot of sixteen local genotypes and seven commercial sweet cherry and sour cherry cultivars to Pseudomonas syringae was studied in glasshouse condition. Shoot evaluation was performed by inoculating winter shoots and leaf evaluation by direct inoculation, inoculation in water-agar medium and using vacuum pump. A pathogenic strain of P. syringae was isolated from an infected sweet cherry tree in Karaj, identified by phenotypic and molecular methods and used as inoculum. Based on the results, high variation was observed in leaf and shoot reactions to the bacterium. Grouping based on shoot resistance levels indicated that 43.5% of genotypes were relatively resistant, 43.5% intermediate and 13% susceptible. Hamedan and KB8 were rated as the most susceptible and resistant genotypes, respectively. The most efficient method for leaf inoculation was through using vacuum pump.The results of this method indicated that 6% of genotypes were relatively resistant, 35% intermediate and 59% susceptible. Blamarka and Dirres-e-Daneshkade were rated as the most susceptible and RD Jobileum as the most resistant genotypes. As no correlation was observed between leaf and shoot susceptibilities, leaf susceptibility level could not be indicative of resistance of shoots to bacterial canker.

Nine date palm cultivars present in Behbahan Agricultural Research Station were evaluated in a randomized complete block design with three replications for response to lesser date moth during 2008 and 2009. Three trees from each cultivar Kabkab, Khasi, Haj-Mohammadi and Zahedi (Behbahan), Gantar and Khazravi (Shadegan), Piarom and Mezafati (Hormozgan) and Shahani (Fars) were selected randomly. Percentage of infested fruits and infestation severity were recorded based on non infested and infested date fruits on eight bunchlet.Analysis of variance, mean comparison, cluster analysis and correlation analysis were used to evaluate cultivars susceptibility. Cultivars Khasi and Kabkab with 27.35 and 22.94, and Shahani, Khazravi and Zahedi with 11.24, 12.01 and 12.057 had the highest and the lowest percentage of infested fruits, respectively. Cultivars Khasi and Kabkab with 1.39 and 1.30 had also the highest infestation severity. Based on cluster analysis, the date palm cultivars were classified as susceptible (Khasi, Kabkab, and Mezafati) and non susceptilde (Shahani, Zahedi, Piarom, Khazravi, Gantar, and Haj-Mohammadi). Correlation analysis showed that there was a significant positive correlation between infestation severity and bunch number and ratio of fruit weight/kernel weight and a significant negative correlation between infestation severity and fruit skin thickness.

This research was conducted in 2009 and 2010 to survey the efficiency of indices used for fire blight resistance evaluation on 30 genotypes from national quince collection of Kamalshahr, Karaj, Iran in orchard condition. Disease susceptibility was monitored by three indices including index of Beltsville, developed by USDA (IUSDA), index of susceptibility of varieties (ISV) and index of frequency (IF), and the results were compared then with total percentage of fire blight damage on trees (IT). IF had the highest correlation with IT, but each single index also demonstrated various efficiency for evaluation of real disease damage and severity on the quince trees, therefore, due to the variant results, the genotypes were classified differently in resistant classes. In order to obtain more reliable judgment on the susceptibility of quinces by accumulated indices, cluster analysis of the results was found to be more effective scale for assessment of susceptibility compared to a single index. Based on these results, quince genotypes derived from Guilan province showing highest level of fire blight resistance were identified as the most suitable genotypes for using as source of resistance in breeding programs.

In order to study genetic diversity and relationships between yield and some morphological traits, 648 common bean accessions were selected from the Gene Bank of Agricultural College, University of Tehran, Karaj, Iran.The accessions were planted in 2009 in the Augment Design without replication under normal and limit irrigation conditions. Traits such as days to 50% flowering, days to maturity, period of seed filling, number of seeds in pod, 100 seed weight and total yield were recorded during the growth period. The means and ranges of variation for the evaluated traits showed a high diversity among the genotypes. The results of correlation analysis showed that total yield had a positive correlation with studied traits in both normal and limit irrigation conditions. Factor analysis showed that three factors in normal and limit irrigation conditions, explained 72.57 and 73.37 percent of the total variance changes, respectively. Cluster analysis classified genotypes in to eight clusters in both conditions.

Many barley cultivars especially hull-less genotypes are susceptible to covered smut caused by Ustilago hordei (Pers.) Lagerh. Artificial inoculation of disease for resistance evaluation is also difficult and common methods of artificial inoculation are inefficient. The present study was conducted for three years to evaluate resistance of 27 hulled and hull-less barley advanced lines and cultivars to covered smut with three inoculation methods. A factorial experiment based on complete randomized block design with three replications was performed for two years. Three inoculation methods including inoculation only in field by spore spraying, inoculation only in laboratory by spore suspension and inoculation in field+laboratory, together with a non-inoculated treatment (check) were considered as the first factor and barley genotypes as the second factor. Number and percentage of infected heads were recorded at harvest time. Based on the results, inoculation in field+inoculation in laboratory was the most effective method for artificial infection of covered smut followed by inoculation only in laboratory. Inoculation only in field did not lead to induction of sufficient infection. Therefore, considering the easy application, inoculation only in laboratory can be recommended as the most practical method for artificial inoculation of the diseases. In this study line MOLA/SHYRI//ARUPO*2/JET/3/…. Was assessed as the highly resistant and cultivar Jonob as the highly susceptible genotypes.

To improve commercial grapevine cultivars, it is necessary to apply such methods that by cultivation of a certain number of vines in a certain area, higher yield could be harvested. To achieve such a goal, healthy stocks with resistant to pests and diseases, high fructification and high quality of vines are needed. All these properties can be obtained successfully through clonal selection. Viticulture in Iran is threatened traditionally by propagation and distribution of vines very likely infected with bacteria and viruses. To select virus free and superior clones of grapevine cv. Keshmeshi Sefid, this study was performed in vineyards of Orumieh region, in northwest of Iran.Based on qualitative and quantitative traits, several superior and stable accessions were selected during three years at mass selection phase. DAS-ELISA by poly clonal antibodies was used for detection of clones infected with Grapevine fan leaf virus: GFLV, Arabis mosaic virus: ArMV and Grapevine leaf roll virus: GLRV at sanitary selection phase. Based on the results, all 27 superior clones were free of ArMV and GLRV, while nine clones namely Gol102, Beh-1, Beh-2, Lash1-2, Kah-5, K11, Gol1-3, Kaz1-1 and clone 59 were infected with GFLV indicating the prevanlence of GFLV in Orumieh vineyards.More investigation is underway to introduce the superior clones with high yield quality and quantity and resistant to viral diseases.

Blast (Magnaporthe grisea) is the most important disease of rice in Mazandaran province, north of Iran, which causes severe damages annually on susceptible cultivars. Tarom Mahalli is a local aromatic cultivar with high cooking quality and marketability, but very susceptible to blast. To protect this cultivar and similar susceptible cultivars against rice blast, farmers have to use high amounts of chemicals every year. In the present study, an attempt was done to transfer rice blast resistance genes Pi -1 and Pi -2 from near isogenic lines C101LAC and C101A51 (as male parents) to Tarom Mahalli (as femate parent) to develop a resistant cultivar with high cooking cultivar. Necessary crosses and backcrosses were accomplished between parents and hybrids developed during three years were selected based on morphological, virulence and molecular markers (RG64 and C481). Selected plants were finally exposed to a mixture of races of the pathogen prevalent in Mazandaran. Based on the results of this investigation, several plants were selected that had morphological and physiological characteristics of Tarom Mahalli and carried Pi -1 and Pi -2 resistance genes. The infection types of the hybrids were 1-2, while those of the Tarom Mahalli were 4 and 5. Although some morphological and qualitative characteristics of the progenies were slightly different from those of Tarom Mahalli, but transferance of resistance genes gave it a satisfactory protection against the disease.

Development of new cultivars with high seed yield and desirable characteristics are major goals of lentil program for Moderate and Semi Warm Climate of Iran. Kimiya is a new lentil (Lens cultivars Medik) cultivar with high-yield, yield satability and adaptability to rainfed conditions. The Iranian Agricultural Research, Education and Extension Organization issued registration for Kimiya on 9 August 2009. This cultivar originated from a cross between ILL5582 (origin of Jordan) and ILL 707 (origin of Tunisia) made in ICARDA and received as a pure line (FLIP 92-12L) in 1995. The new line was entered in to A and B test experiments and evaluated for seed yield and agronomic performance in Kermanshah (Sararood), Gonbad, Shirvan, Gachsaran, Koohdashat and Ilam (Shirvan Chardavoul) Stations during 1995-2007. Due to high yield potential and desirable characters, it was selected and forwarded to yield stability traits carried out in Kermanshah, Lorestan, Ilam, Shirvan and Gonbad during 2001-04 under rainfed condition. Line FLIP 92-12L with a mean yield of 1263 kgha-1 in Kermanshah, Lorestan, Ilam, Shirvan and Gonbad produced significantly higher yield than local check. Results of statistical analysis on seed yield, using different methods of stability showed that this line was one of the most stable genotypes. Based on the results of on-farm experiments in five locations in Kermanshah and two locations in Lorestan during 2002-04, the new this line with 1289 kgha-1 produced 50 percent higher yield than local checks. In de monstration field s in four locations of Kermanshah during 2003-07 this line with 1093 kgha-1 produced 47% higher yield than local check.

Line TO/CAL/3/7C//Bb/CNO/5/CAL//CNO/Sn64/4/CNO//Bad/DAR/3/KL/6/Sabalan was received from ICARDA under International Winter Wheat Improvement in 1999-2000 cropping season. Based on its favorable agronomic characteristics, it was selected for further evaluations in advanced and elite yield trials in main research stations of Dryland Agricultural Research Institute (DARI) and on farm yield trials in moderate cold and cold regions of Iran. The results of these experiments revealed that this line was more tolerant to drought and yellow rust, produced significantly higher and more stable yield than the check cultivars and showed good performance in rainfed and supplemental irrigation conditions. One of the best features of this line is its earliness. Days to heading and maturity in this line were 10 to 12 days earlier than those of Sardari and Azar-2 check cultivars and due to this feature it escapes from terminal drought and heat stresses, therefore grain shriveling in this line is relatively less than in Sardari and Azar-2. Grains of this line also have very good bread quality with 12.5 percent of protein. Based on its superiority and good performance compared to the check cultivars in main stations of DARI and farmer’s field, this line was introduced and named “Rijaw” in 2010 and recommended for cultivation at rainfed and supplemental irrigation conditions in moderate cold regions of Iran.