SEED AND PLANT IMPROVEMENT JOURNAL
Year:2016 | Volume:32-1 | Issue:1|Papers Count:9

Producing hybrid lettuce is prevented by flower structure and usually lead to selfing. Based on it, this experiment was carried out to evaluate the performance of different physical and chemical emasculation methods for producing lettuce hybrid seed. A numbers of cultivars with dominant and recessive traits were used as male and female parents, respectively. In the first experiment, physical emasculation methods including washing, forceps and combination of them together with a control treatment were compared. In the second experiment, the effects of gibberellin concentrations of 50, 100, 200 ppm and control were evaluated. The results of analysis of variance in the first experiment showed that method of emasculation had significant effect on the percentage of produced hybrid seeds, while the effect of parent pollen was not significant. However, the mean comparison results showed no significant difference among emasculation treatments. In the second experiment, different concentrations of gibberellin had significant effects on the percentage of produced hybrid seeds and non-fertile pollens. The highest percentage of hybrid seeds (about 85 percent) and non-infertile pollens (about 80 percent) were obtained by using 200 ppm gibberellin.

Study and comparison of potential forage yield and morphological traits of imported Berseem cultivars with current clover cultivars, will increase diversity among clover cultivars and increase forage production in the country. This experiment was conducted in a randomized complete block design with thirteen cultivars and four replications in Karaj. The two-year combined analysis of variance showed that the effects of year and cultivars were significant for the fresh and dry matter forage yield and morphological traits at 1% probability level. This implies to genetic variation among cultivars and differential effect of year on forage production and morphological characteristics of Berseem clover cultivars. Mean comparisons showed that Polycross cultivar with 70.25 and 16.65 tha-1 and Isoleh-e-Mesri cultivar with 48.84 and 10.70 tha-1 had the highest and lowest fresh and dry matter yield, respectively. The effects of cultivar and year on some morphological characteristics such as plant height was significant and there was a positive and significant correlation between these traits and forage yield. The imported cultivars Wiener, Elite 2 and Selected line, and the local cultivars Tolidi-e-Dezful, Polycross Karaj and Sacromont Mazandaran with 68-69 tha-1 fresh and 16-16.5 tha-1 dry matter yield were the best cultivars, and compared to the control cultivar (Tolidi-e-Karaj) showed 7% and 10% superiority for the fresh and dry matter forage yield, respectively. There fore, these cultivars can be recommended for cultivation in Karaj.

In Iran quince cultivar Isfahan is the dominant commercial cultivar that demonstrates low fruit set and limited crop load in the orchards without pollinizers. This research was performed to determine the self–incompatibility and the most suitable pollinizer for Isfahan cultivar. For this purposes, effects of four different pollinizers including KM1, PK2, KVD2 and NB4, and two control treatments, self pollination and open pollination were evaluated on fruit set and fruit quantitative and qualitative characteristics of cultivar Isfahan for three years (2006-2008). Based on the results of mean comparison of fruit set percentage, there were a significant difference among different pollination treatments, except KVD2 and NB4. The maximum percentage of fruit set was 23.42 which gained by KM1 genotype, and the minimum 8.4% was related to the self pollination. The mean comparison of self pollinated treatments on fruit weight showed a significant difference between KM1 and other treatments. The KM1 genotype with high overlap blooming period and highest percentage of fruit set and seed number per fruit was recognized as the best pollinizer for quince cultivar Isfahan. Parallel assessment for isolation and evaluation of diversity in S locus of quince genomes revealed the presence of S alleles in this locus in most tested genotypes. Interestingly, more suitable quince genotypes for using as pollinizers, KM1 and NB4, contained two divergent S alleles in this locus.

Fusarium wilt is considered as the second important pathogen of chickpea. Annual yield reduction caused by the disease has been estimated 10-90%. The ability of the pathogen to survive in soil for several years, even without the host, makes the control of disease very difficult. However, using chickpea cultivars that are resistant to fusarium wilt is the most effective and environment friendly method. In the present study, molecular markers (RAPD and SCAR) were used to identify chickpea genotypes containing the resistance genes to races of 1, 2, 3, 4 and 5. Genomic DNA was extracted using CTAB method from 42 chickpea genotypes. Then, polymerase chain reaction was carried out using CS-27 and CS-27700 molecular markers. Results showed that out of the 42 genotypes, 41 ones were susceptible to all the five tested races which had no resistance gene. Only Flip 06-152c line was resistant to these five races. The results of phenotypic resistance evaluation of genotypes under greenhouse condition confirmed the results of molecular evaluations.

This study aimed to evaluate the characteristics of fruit and seed of some citrus genotypes and their progenies obtained from open pollination, grown in the collection garden of Citrus Research Institute in Ramsar and Darab (Fars), using 27 pomological and morphological characteristics. According to the results, significant differences in most traits related to fruit characteristics of parents and vegetative characteristics of progenies were observed among genotypes. Results of simple correlation analysis of fruit characters showed significant positive and negative correlations between some traits such as fruit length and width, fruit skin thickness and number of seeds and pulp per fruit, fruit pH and EC, seedling height and diameter and leaf number, progenies leaf and petiole length and width and leaf length, width and leaf number. Cluster analysis using all traits, divided genotypes into two main groups at distance of 25. Most genotypes (28) placed in the first group while six genotypes in the second group, which had the highest number of seeds per fruit and maximum fruit skin thickness and weight. First cluster was divided into two subgroups at distance of 14. Genotypes of the first group had more seeds per fruit and higher fruit skin thickness than the second group. They had also minimum soluble solid content. The second group had the lowest fruit skin thickness and lower number of seeds per fruit. This group had more soluble solid content than the other groups. Cluster analysis of vegetative characters using all traits separated lemons and Cleopatra from other genotypes. These genotypes had the highest number of leaves, but smaller in size than other genotypes and had the highest number of thorns.

This study was conducted to investigate the genetic diversity and classification of 52 barley genotypes from Egypt, Iran and China (obtained from Dryland Agricultural Research Institute, Maragheh) using microsatellite markers. DNA was extracted from young barley leaves and amplified PCR products were separated on 4.5% polyacrylamide denaturing gel electrophoresis using 59 microsatellite primer pairs. From 40 microsatellite primer pairs with good amplification, 134 polymorphic alleles were identified with average alleles of 3.4 per marker and the PIC average for all of the markers was calculated 0.47. Based on the results, microsatellite markers showed high polymorphisms in barley genotypes. In cluster analysis based on UPGMA method, genotypes were classified into two main groups and two-rowed and six-rowed genotypes were diverged mostly from each other. Desirable genetic diversity was also detected within and between groups. Based on association analysis, 18 informative markers for drought compatibility were identified, which after confirmation in other tests could be used in breeding programs. In addition, these markers can be used efficiently for assessment of genetic diversity and classification of barley germplasm.

Hazelnut is one of the important economical products of Iran which due to high environmental variation of the country, its cultivation could be extended. In this research, the adaptibility of eight local and imported hazelnut cultivar including Fertile de Coutard, Rond de Pimont, Negret, Rasmai, Shastak 2, Pashmineh 89, Gercheh and Gerdoe 89 was studied in Alamout of Qazine. The plants were cultured at 4×4 meter distance in 1989 in Ornamental Plants Research Station of Alamout and their vegetative and reproductive characteristics were studied during years 2011 and 2012. Results indicated that the fruit set date was earlier in cultivars Pashmineh 89, Gercheh, Negret and Gerdoe 89. Tree yield, number of suckers and oil percentage differed in cultivars and the highest yield was produced by Pashminh 89, Gercheh and Gerdoe 89 (3.58, 3.34 and 3.00 Kg/tree, respectively) and the lowest by cultivar Fertile de Coutard (0.36 kg/tree). The lowest oil percentage was recorded in Fertile de Coutard (57.06%) and the highest in Rond di Pimont and Negret (66.80% and 66.77%, respectively) cultivars. Based on the result, among local cultivars, Gerdoe 89, Pashmineh 89 and Gercheh and among introcuced cultivars, Negret were recognized as the most adaptable cultivars and Rasmi was the best pollinizer for Alamout area. Cultivars Rond de Pimont and Shastak 2 exhibited moderate adaptability and Fertile de Coutard did not show a suitable adaptability in Alamout condition.

To evaluate resistance of maize late maturity lines and hybrids to southern corn leaf blight disease (Bipolaris maydis), an experiment was performed in randomized complete block design with three replications in Karaj and Sari during 2013, using seventeen maize lines and hybrids. Artificial inoculation was carried out two times, first by injection of spore suspension into the whorls of the plants at 3-4 leaf stage, and the second by inoculation of infected sorghum seed with the pathogen into whorls by bazooka at 6-8 leaf stage. Disease severity on leaves of inoculated plants was scored one month after the second inoculation. The results of analysis of variance and means comparison indicated significant differences among lines and hybrids for disease severity. Among eight hybrids, only KSC 708 (A679 × K19) exhibited resistance response (R). Five lines were moderately resistant (MR) among them two commercial lines MO17 and K19 had disease severity less than 10%. Based on the results of this experiment, two latter lines were recognized as favourable sources of resistance to the disease. Line K19 is the paternal parent of hybrid KSC 708 (A679 × K19) which was resistant in this investigation.

Having knowledge and correct understanding on genetic control and architecture of agronomically important traits are essential keys in breeding programs. In this investigation, genetic parameters of some agronomic traits of seven cultivars and lines of sesame Ultan, Darab 1, Varamin 2822, Dashtestan 2, Karaj 1, early maturity Palestinian, and TLHE, which were crossed directly and reciprocally, and their progenies (N=42), were evaluated using Greefing method 1 and mixed model B. Analysis of variance results indicated significant differences among the parents and their hybrids for all the traits, except seed oil content, general combining ability (GCA), and specific combining ability (SCA). The reciprocal effects for all traits except seed yield were significant. Relative contribution of GCA to SCA indicated that number of capsule in main stem, height of the first capsule, capsule length, and seed oil content were more prominently controlled by genes with additive mode of action, and the rest of the traits were mostly governed by non-additive mode of actions. Estimation of broad sense heritabilities varied from 48.9 to 90.5 for fertile length of the main stem and number of capsule on the main stem, respectively. Number of capsule on the main stem with 67.64% and height of the first capsule with 60.43% had the high narrow sense heritability, indicating the validity of these traits in selections. The analysis was able to define the lines showing the best general combining abilities.