مجله علوم باغبانی ایران
سال چهل و چهارم شماره 3 (پاییز 1392)

The genus Ocimum belonging to Lamiaceae is considered as one of the most economical medicinal plants throughout the world. It is used in medicinal tea، and essential oil production، in spices، as vegetable، and also as a pot herb. The aim followed in this study was to evaluate the genetic diversity of 38 native populations collected from different geographical origins of Iran along with two foreign breed cultivars (Opal and Keshkeni Luvelou) as control. A number of 32 field conditions qualitative and quantitative morphological traits were taken into account. Taxonomic studies revealed that the samples belonged to 3 species of: O. ciliatum (23 populations)، O. minimum (1population)، O. basilicum (15 populations). According to analysis of variance highly significant differences were observed among the populations. Duncan’s Multiple Range Tests indicated that the accessions were significantly different in all the evaluated parameters. The highest plant height (49/5 cm) and inflorescence whorl number (11/3) were obtained from population 24، while the highest inflorescence heights obtained from accessions 6 and 13 (15/1 cm). The accessions 4 and 5 benefited from the highest leaf dimentions of length and width.

To investigate the role of Silicon (Si) in alleviating the effects of salinity on quality and quantity of cut rose flowers ‘Hot Lady’cultivar was grown in hydroponic culture media. Different levels of silicon (0، 50، 100 and 150 mg L-1) as Si were mixed with 28 mM NaCl (EC ≈3. 8 dS m-1) levels، used in an RCBD experimental design. The results indicated that Si in 50 and 100 mg L-1 had beneficial effects on growth and quality of cut roses and also could alleviate the deleterious effects of salt stress on storage life and quality of cut flowers by decreasing electrolyte leakage percentage. K، Ca and P absorption increased and Na decreased in leaf and shoot of Si received plants. However، 150 mg L-1 Si with or without NaCl couldn’t affect all of measured traits. This finding indicated that the stimulation of the vegetative growth of roses by Si under salinity conditions was due to mitigation of toxic Na or Si effects on cell wall and ion distribution in treated plants.

A Study of the combining ability and gene effects، that can obtained through diallel cross analysis provides considerable information to breeders for a design of breeding programs. Inheritance and genetic control of yield and its components were studied in a full diallel cross for seven Iranian cantaloupe cultivars namely: Rish-baba، Shah-abadi، Samsouri، Dastjerdi، Magasi-neyshabour، Till-toroq، and Savei. Analysis of variance revealed significant differences within genotypes. The general combining ability، specific combining ability and reciprocal effects were significant for all the traits. Rish-baba parent benefited from the highest positive general combining abilities for the number of fruits، flesh thickness، and as well for yield. Furthermore، the cross Rish-baba × Savei exhibited the highest specific combining ability for the traits yield and number of fruits. Favorable heterosis based on the superior parent was observed for yield، fruit weight، number of fruits، and as well for fruit length. Additive gene actions played a more important role in controlling the traits of fruit length، fruit width، and flesh thickness، while the role of non-additive gene actions was more conspicuous than those of additive gene actions in controlling the traits of number of fruit، fruit weight، and yield.

A set of 18 Simple Sequence Repeat (SSR) primer pairs was employed to assess the genetic diversity in a collection of 52 melon genotypes that consisted of 24 melon accessions representing different horticultural groups of Iranian cultivated melons، along with 28 reference accessions from diverse foreign geographical origins. All the studied SSR loci were polymorphic، confirming their potential for genetic analysis in melons. A total number of 141 alleles were detected among all the genotypes، out of which 79 alleles with an average of 4. 38 alleles per locus were observed for the Iranian accessions. The low variability within Iranian melon accessions was reflected by the low values of the observed heterozygosity (with an average of 0. 12)، indicating either a lack of intercrossing between accessions or a high rate of inbreeding. Consecutive selections by farmers for keeping accession traits might be considered as an explanation for the relatively high observed homozygosity. Values of observed homozygosity for ‘Suski-e sabz’ and ‘Khatouni’، as the most cultivated melons in Iran، amounted to 0. 98 and 0. 99، respectively. The highest level of polymorphism was detected among the Group Dudaim populations (with 100 percent of polymorphic loci).

The initial step in any breeding program including the breeding of walnut is an evaluation of the genetic diversity of its population and on identification of its superior and promising genotypes. This research was carried out during 2009-2010 growing seasons to evaluate the walnut genotypes، population grown in the vicinities of Eghlid city، as one of the richest walnut population regions in the North of Fars Province، Iran. According to local Ministry of Jehad Agriculture Office expert،s recommendations، and also orchard owners، views، 110 walnut genotypes were selected. Following primary observations based upon the fruit، not showing any symptoms of blight and chilling with nut weight being more than 6. 5 g، 48 genotypes were selected for further evaluations. Phenological and pomological traits of selected genotypes were evaluated according to UPOV and IPGIRI descriptors. The results revealed that nut weight، kernel weight، kernel percentage and shell thickness varied in the ranges of: 8. 6-18. 8 g، 2. 8-9. 5 g، 17. 5-62. 6 % and 0. 86-3 mm، respectively. The superior and promising genotypes included E5، E9، E20، E22، E26، E28، E30، E34، E35، E35 and E49، for which the nut and kernel weights varied within the ranges of 11-19. 8 and 6. 5-9. 2 g.

Almonds are self incompatible، the incompatibility being controlled by a multi allelic (S-alleles) single gene. The incompatibility alleles were studied in 96 samples of wild almonds and related Prunus species from 10 taxonomic groups. Polymerase Chain Reactions were carried out with six primer sets including: three degenerate primer pairs (PaConsI-F(FAM) /EM-PC1consRD، PaConsI-F (FAM) /EM-PC3consRD، EM-PC2consFD/EM-PC3consRD)، one primer pair (AS1II/AmyC5R)، one allele specific primers pair (CEBASf/AmyC5R)، and a set of multiplex primer (AS1II/CEBASf/AmyC5R). The number of amplified bands (155) as well as their size ranges were recorded as higher than those in the previous reports. None of the primer sets amplified self compatibility allele (Sf). The sizes of amplified alleles compared with previous reports in almond cultivars، and the alleles were labeled accordingly. Alleles S9، S2، S13، and S25 had highest frequencies (12. 26، 8. 39، 7. 74 and 7. 74 respectively). Alleles S16، S17، S18، S19، S22، and S28 were not observed، and while S15 S26 were of the lowest frequency (0. 65) in the studied samples. Presumably، geographical distribution of these species had influenced their S-allele frequencies. The putative groups were clustered by using amplified allele sizes from the first degenerate primers (PaConsI-F(FAM) /EM-PC1consRD). This clustering was in match with botanical classification.

Drought stress is one of the phenomena that adversely affects growth and quality of plants، with turfgrass being no exception. For a study of the responses of Poa pratensis L. cv. ’Barimpala‘ to time periods of drought stress، turfgrass seeds were cultivated at 60cm depths in cylindrical pots of 15cm diameters and placed outdoors. Plants were daily irrigated to the point until drainage occurred. Following the establishment of the plants irrigation was withheld until leaf wilting occurred in most plants to a level of 80% when they were rewatered. All the traits were assessed within 5d intervals throughout the experiment. Drought stress declined shoot growth، shoot height، grass quality and chlorophyll content، while electrolyte leakage، leaf wilting and proline contents being increased with prolonged stress. Leaf wilting decreased during rewatering and at 11d was similar to control plants. In stress conditions، RWC decreased after 5d past. Oxidative injury was induced due to increase in lipid peroxidation. Drought stress had no effect on height and dry weight of roots. Activities of Catalase (CAT)، Ascorbate Peroxidase (APX) and Peroxidase (POD) were not significantly different from control plants up to 5d past then began to increase at 10d.

This study was performed in year 2010 to evaluate the effect of locality and date of collection on germination and growth of Pimpinella aurea DC. seed. The experiment was a factorial one، based upon a completely randomized design of four replications. Seeds were collected from three localities in Tehran Province (Tochal، Vardavard and Lavasanat)، at their initial developmental and fully developed stages. Assessed traits included: germination percent، Mean Germination Time (MGT)، R، Seed Vigor Indicator (SVI)، Radicle length، Plumule length and 1000-grain weight. The results revealed that locality significantly affected germination and MGT، but the date of collection did not significantly affect it. The effect of interaction between locality and date of collection significantly effected germination، MGT، R، 1000-grain weight، SVI and Plumule length at a 1%. Level of probability. Mean comparison showed that the most germination (65. 50%)، the highest 1000-grain weight (1. 900 gram) and SVI (16. 26) belonged to Lavasanat seed whilst the lowest germination belonging to Tochal with no significant differences evident with Vardavard seed. According to the obtained results Lavasanat seed is finally recommended to be introduced for cultivation.

Five levels of Salicylic Acid (SA)، (0، 2، 4، 6 & 8 mM) were sprayed on strawberry cv. Comarosa fruit bearing plants in a hydroponic culture. Growth، yield & fruit quality attributes were assessed. Vegetative characteristics (crown number، root & shoot weight)، reproductive traits (yield، fruit number as well as shape)، fruit quality، macro elements (Ca، Mg، K & P)، dry weight & ash were evaluated. Among treatments، the 6 mM of SA resulted in the most favorable effect on quality، growth & yield of strawberry. It also led to the highest yield، firmness، vitamin C، TSS، fruit redness rate (a*) and pH of the fruit juice. However fruit lightness (L*) and titrable acidity were relatively high for this concentration. Effect of control treatment on plants and fruit attributes was undesirable، except vitamin C & dry matter. SA of 8mM concentration produced larger fruits with higher moisture. However، TA، pH of fruit juice and TSS were high in this treatment، but the quality was very low. Effect of 4mM of SA on yield، firmness، a*، K content and moisture was favorable، but such other attributes as vitamin C content، dry matter and TA were very low.

Postharvest senescence is a major factor، limiting the marketing of many species of cut flowers، including roses. Considerable efforts have been devoted to developing postharvest treatments to lengthen the extend of the marketing period. The purpose of this study was to determine the most suitable nitric oxide، and Thidiazuron concentrations to increase the antioxidant activity as well as protein content in Rosa cut flowers. The experiment was conducted in a completely randomized design of three replications. Treatments consisted of: four different Sodium Nitro Prusside (SNP) concentrations (0،20،40 and 60 µm/l) along with Thi Diazuron (TDZ) in three levels (0،20 and 40 µm/l)، and as well with 20% pulsings of sucrose. Some such physiological traits as peroxidase and catalase activities as well as the protein in leaf and in petals of Rosa cut flowers were assessed throughout the study. Results showed that the 40µm/l of TDZ treatment increased protein in the leaf and petals، and as well the catalase activities in the leaf.