IRANIAN JOURNAL OF HORTICULTURAL SCIENCE AND TECHNOLOGY
Year:2006 | Volume:7 | Issue:2|Papers Count:8

Onion (Allium cepa L.) is one of the most important vegetables in Iran and the world. Since Iran is located in dry areas of the world, drought occurrence can affect onion yield, prevalence and outbreaks of onion pests, especially onion thrips. In order to study the effects of different irrigation regimes and insecticide application on onion thrips and bulb yield, four irrigation regimes (irrigation after 40, 50, 60 and 70 mm cumulative evaporation from class A pan) with and without insecticide application were used in a 2´4 factorial experiment in a complete randomized block design with 4 replications in 2004. Each experimental plot was consisted of 4 photometers with 50 and 90 cm diameter and depth, respectively, and was planted with 12 onion seedlings. The population density of onion thrips was determined weekly by testing two plants. Mean number of leaves, plant height, fresh and dry weights and bulbing ratio were measured in mid and late August and mid September. Results showed that the longer irrigation interval reduced population of the onion thrips and fresh and dry weights, but did not significantly affect number of leaves and plant height. Bulbing ratio was higher in longer irrigation interval sprayed plots than shorter irrigation interval unsprayed plots. Maximum and minimum bulb yield was obtained in 50 and 70 mm irrigation treatments, respectively. Spraying reduced thrips density and consequently increased fresh and dry weights, plant height, bulbing ratio and bulb yield. There were significant interactions between irrigation regimes and spraying for most agronomic traits and thrips populations.

Due to the special medicinal benefits of the juice and mucilage of Aloe (Aloe vera L.), which are obtained from the leaves, today, these are widely used in pharmaceutical industries and cosmetics. Generally, Aloe can be propagatesd vegetatively but its propagation rate is too low.  Therefore, a research was conducted to increase the rate of vegetative propagation and to obtain the best method of callus induction through in vitro culture of segmented leaves in tissue culture laboratory of Ramin Agricultural University of Ahwaz in 2004. The research was arranged in a completely randomized design. After surface sterilization, the leaf explants. were cultured aseptically in MS medium containing 3% sucrose and 0.8% agar supplemented with different concentrations and combinations of BAP, kinetin and 2,4-D, NAA and IBA for callus induction and shoot regeneration. The rate of callus induction and shoot regeneration were recorded after 4-5 and 12 weeks, respectively. Rooting media were MS medium containing 3% sucrose and 0.8% agar supplemented with different concentrations of NAA or IBA or without plant growth regulators. Root number, root length and root thickness and branching were compared between different rooting media after 6 weeks. Results showed that the basal portions of young leaves were suitable for callus induction. In this research the incidence of callus was better in darkness than in light. Actually, the rate of callus induction was very low in light. The combination of 2, 4-D and kinetin was the best for callus induction. Shoot regeneration was observed in MS medium containing BAP and combination of BAP and NAA or IBA. The best rooting medium was MS supplemented with 0.5 mg l-1 IBA.

Inter Simple Sequence Repeat (ISSR) markers is a technique that is based on PCR and using micro satellite sequences in order to produce multilocus markers. Genetic diversity of 15 olive cultivars of Isfahan University of Technology collected from different origins (Iran, Spain, Syria, America and Greece) was evaluated using ISSR markers. Ten single ISSR primers and 2 combined ISSR primer pairs were used. A total of 243 loci were amplified in which 203 loci were polymorphic among olive cultivars. ISSR banding patterns were transformed into binary data of presence–absence and matrices were analyzed with NTSYS pc 2.02 software program. Mantel correspondence test was conducted to choose the best similarity coefficient. A dendrogram constructed using the Simple Matching (SM) coefficient with unweighted pair group mathematical average (UPGMA). Cluster divided cultivars into two groups of 3 and 9 cultivars and three single groups. The PCA data confirmed the results of clustering. Most of the Iranian olive cultivars were clustered in one group confirming their morphological characters similarity. On the other hand, these cultivars were located close to Spanish cultivars; therefore it is possible to have the same evolutionary origin.

To select suitable and compatible pollinizers and also to facilitate breeding programs in fruit trees, the genotype with S alleles in each cultivar should be determined. Because of the juvenile period of fruit trees, traditional methods are costly and time consuming. More recently, an easy and reliable identification of S-alleles by PCR is of great interest. In order to identify the genotype of S-alleles, genomic DNA from young leaves of nine apricot cultivars and also segregating progenies from a breeding program in Spain, was extracted. PCR amplification was carried out using specific primers. Results showed that in all studied cultivars S-alleles were amplified with specific primers designed based on the first and second introns. Self-compatible cultivars shared the same band with 'Currot' as a Spanish self-compatible cultivar. Two out of the nine cultivars showed the same bands for S-alleles. S-genotypes in progenies from 'Goldrich'×'Pepito' cross was detected as ScS1 and ScS2 in 6 and 3 seedlings, respectively. Furthermore, self-compatible progenies were determined when self-compatible cultivars were crossed together or with self-incompatible ones.

Nine commercial almond cultivars ('Sahand', 'Yalda', 'Shukofeh', 'Azar', 'Ferragnes', 'Nonpareil', 'Monagga', 'A200' and 'A230') were used for determination of the flower initiation time, stages of morphological development of flower bud, flower buds density in spur, branch spur number of and pistil length. The experiment was conducted in 'Sahand' Horticultural Station during three years. For determination of flower initiation, buds were sampled weekly since 15 August. Results showed a positive correlation between initiation and flowering times. The first flower initiation period was observed in 'Monagha' (27 August) and the last flower organogenesis period was observed in 'Sahand' (26 November). Analysis of variance showed significant differences among cultivars in all studied characteristice (P≤5%). 'Sahand' produced the highest spur in each meter of branches with average of 46 spurs and 'Monagha' produced the highest pistil length with average of 1.85 cm. The important point in all the cultivars used was normal fruit setting despite short pistil production in some of them.

Experiments were conducted in the southern part of east Azarbaijan in 2004 and 2005 on the 18 year-old grapevines in Malekan area, to investigate the effects of spraying of boric acid and urea on the qualitative and quantitative characteristics and some physiological parameters of Vitis vinifera 'Soltani'. The plants were sprayed with 0, %1 and %1.5 of urea and 0, 1500 and 2500 mg l-1 of boric acid. Experiments were arranged in a randomized complete block design. Foliar application of boron with different concentrations and different periods affected the berry set percentage, total soluble solids (TSS), berry sugar, cluster weight and other characteristics. Application of urea increased the next year number of clusters per bud in the periods of prebloom and post petal abscission. In this research, although increase in total leaf protein was not significant using urea treatment, there was a positive correlation between the amount of total leaf protein and the number of clusters per bud. The amount of bud soluble carbohydrates increased in some treatments using boric acid. This increase did not affect the fertility of buds.