Journal of Plant Production Research
Year:2011 | Volume:18 | Issue:2|Papers Count:10

In order to achieve high quality seeds, producers must be able to estimate the accurate harvest maturity time seeds. The objective of this study was to investigate changes in seed quality during seed development and maturation in the two cultivars native of the Sari and Gorgan and two cultivars modified of the Darab14 and Yellowhite. A field experiment was conducted in during 2009 at Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. The results indicated that physiological maturity (maximum dry weight of seed) achieved at about 68 (889), 70 (957), 77 (1036) and 75 (1012) days after flowering (growth degree days) for Yellowhite, Darab14, Gorgan and Sari cultivars, respectively. At this date, the seed moisture content was 29, 40, 27 and 16% (wet basis), respectively. Maximum seed quality occurred at 2 and 24 days later for cv. Darab14 and Yellowhite, and 10 and 6 days earlier for cv. Sari and Gorgan, when compared to physiological maturity of seeds. The results indicated that there was significant difference as aspect the time to achieve to maximum seed quality and physiological maturity in sesame. Generally, for to achieve high quality seeds in sesame, must was done harvest at 900-1000 degree-days after flowering. At the date, the moisture content of seeds were between 25-35% (wet basis) and color lower and middle capsules were change from green to brown or yellow (depending on cultivar). Hence, color identification of the capsules can be used as an additional indicator for sesame harvest.

Self-incompatibility is one of the most important difficulties in almond production which reduce fruit set dramatically. Therefore, breeding almond to produce self-compatible genotypes is very important. In this research, pollen tube growth was studied in 28 genotypes obtained from crossing between Touno (male parent) and Shahrood 12 (female parent) after self pollination by fluorescent microscopy. Flowers were hand pollinated with their own pollen by brush and then bagged. Flower sample were harvested at 24, 72 and 120 hr after hand pollination. Results showed that 24 and 72 hr were not enough time for pollen tube to reach base of style, but 120 hr was suitable time. At 120 h after pollination according to our classification (percent pistil with pollen tube at the base of style), 60.71% of genotypes were self-incompatible, 17.86% of genotypes were doubtful, 7.14% of genotypes were self-compatible and 14.29% of genotypes were recognized as highly self-compatible. On the other hand, according to another type of classification (mean pollen tube number at the base of style), 50% of genotypes were self-incompatible, 32.14% of genotypes were doubtful and 17.86% of genotypes were recognized as self-compatible. Therefore, pollen tube growth observation by fluorescent microscope has been known a useful and practical method to discriminate self-compatible genotypes when they start to flower.

Seed and oil yields, its components and two physiological indices including leaf canopy temperature (Tc) and relative water content (RWC) were evaluated in two spring oilseed rape cultivars (RGS 300 and Hyola 401) under non-stressed and water deficit imposed during stem elongation, flowering and seed filing stages. The experiments were conducted as a factorial consisted of 2 factors including irrigation and genotypes based on a randomized complete block design with three replications. The study was conducted in research center for agriculture and natural resources of East Azarbaijan, Iran (46° 2' E, 37° 58' N). The results indicated that occurring water deficit in all stages, increased Tc and decreased RWC, siliques per plant, seeds in silique, harvest index, seed and oil yields. Significant correlations among RWC, TC, seed and oil yields were observed. Tc and RWC indices could be used to determine water deficit effects in spring oilseed rape cultivars. Since occurring drought during flowering and seed filing stages had the most negative effects on seed and oil yields, therefore it seems that irrigation of spring oilseed rape cultivars during these stages, is important for achieving acceptable yield. Hyola 401 indicated higher amounts of seed and oil yields.

In order to have a successful breeding program, it is important to determine the relationship among the traits. This study was conducted at Research Farm of Isfahan University of Technology to evaluate relationships among some of the agronomic and physiological traits and grain yield of ten bread wheat cultivars in optimum and stress moisture (irrigation after 70±3 and 130±3 mm evaporation from class A pan) conditions in year 2006. Grain yields in both moisture conditions had significant positive phenotypic and genetic correlations with harvest index, number of grain/spike, RWC, chlorophyll a and sum of chlorophylls a and b and had significant negative correlation with RWL. Significant positive correlations were observed between peduncle weight at heading stage and difference of peduncle weights at stages heading and maturity with grain yield and RWC in moisture stresss condition. Factor analysis detected 6 and 7 factors which explained 94% and 94.6% of the total variation in moisture stress and non stress conditions, respectively. Results of canonical correlation analysis in non stress condition showed that among the agronomic traits, days to heading and 1000-grain weight and among the physiological traits, SLW and RWC had the highest contributions to the first pair of canonical variables. Results of canonical correlation analysis in stress condition showed that among the agronomic traits plant height and heading date and among the physiological characters RWC and SLW had the highest contribution to the second pairs of canonical variables.

Sugar type and growth regulators are essential fundamental components of tissue culture media. In this study, different concentrations of some carbohydrate and growth regulators during anther culture and producing somatic embryo of Datura stramonium L. was investigated in MS medium. The MS medium supplemented with 0.5 mgL-1 kinetin and 2 mgL-1 2, 4-D, and also the medium supplemented with 0.25 mgL-1 kinetin and 2 mgL-1 2, 4-D indicated the highest of callus induction. Among the four sugar type applied in this study such as sucrose, glucose, fructose and maltose, the best callus formation was observed in medium containing 4% maltose. The investigation of growth regulators on amount of embryogenesis showed that, the highest frequency of somatic embryo induction on anther-derived calli was obtained in medium containing 1 mgL-1 6-benzylaminopurine (BAP) and 0.5 mgL-1 naphthaleneacetic (NAA).

The aim of this research was evaluathng the aluminum-sulphate concentration levels in preserved solution with stem recutting on longevity of rosa hybrida cv. varlon cut flowers. The investigation was conducted in Horticultural lab, Agricultural College, Zanjan University. Rose cut stems were produced in greenhouse from biennial mother stocks and were placed under the treatment of aluminum-sulphate solution with concentrations of (0, 100, 150, and 200 mg/L) and stem recutting under 2 levels (with and without cutting). Some physiological traits were measured during the study included: longevity, a, b and total chlorophyll content, water absorption content, relative water content, total protein, peroxidase enzymes and catalase enzymes activity of petals. Results showed that different levels of aluminum-sulphate had significant affect on b-chlorophyll content and activity of anti-oxidant enzymes (P<1%), as well as longevity, total chlorophyll content and relative water content (P<5%). Also, stem recutting levels had significant effect on longevity, chlorophyll content, water absorption, relative water content, total protein and activity of anti-oxidant enzymes. The results obtained from interaction of application of aluminum-sulphate by stem recutting showed that application of aluminum-sulphate with 150 mg/l along with stem recutting caused significant increase in b-chlorophyll content, activity of peroxidase and catalase enzymes activity (P<1%), as well as chlorophyll content, water relative content, longevity (P<5%) and that in turn, caused a increase in, longevity and quality and a decrease in percentage of flower senescence.

In the present study, effect of five isolates of Trichoderma harzianum on growth parameters of tomato was carried out as CR Design with six replications under greenhouse conditions. The concentrations 0.5%, 1% and 1.5% inoculums per pot were used. Plant length, shoot and root fresh/dry weight, number of leaves and stem diameter as growth parameters were measured. The results showed that isolates were significant at levels 0.05 and 0.01 by Duncan multiple rang test (DMRT) for their effects on growth parameters of tomato. Isolate T1 had the most growth effect with growth increase of 12.18% at shoot fresh weight, 15.41% at shoot dry weight, 12.70% at root fresh weight, 16.11% at root dry weight, 20.41% at leaf number, 2.50% at stem diameter and 18.51% at plant length. The isolates also showed the most growth increasing at concentration 1.5%. Potential using of these isolates as Plant Growth Promoting has been discussed in this paper.

Chamomile (Matricaria recutita) is a highly valuable medicinal and aromatic plant of Asteraceae family and its anthodia used frequently in pharmaceutical and cosmetic industries. The aim of this study was the evaluation the effect of drought stress induced by Polyethylene Glycol 6000 (PEG) on germination percentage, germination rate, plumule and radicle length of four improved cultivars of German chamomile. The experiment in completely randomized design with two factors in three replications was conducted. The first factor included 10 drought levels (0, -1, -2, -3, -4, -5, -6, -8, -10 and -12 bar that zero bar as control) and second factor included 4 improved cultivars of chamomile. Seeds of Bona (diploid), Germania (diploid), Goral (tetraploid) and Lutea (tetraploid) cultivars were prepared. According to the results, different levels of drought stress and type of cultivar had significant effect on measured characteristics (P<0.01). Results also showed that all the measured characteristics were decreased significantly. Germination percentage in -4 and -6 water potentials decreased to 48 and 16 percent and germination rate decreased to 5.7 and 1.8 and in -8, -10 and -12 bar no seeds germinated. Plumule length decreased more than radicle length in drought stress. Different cultivars of chamomile with diversity in genotype have different responses to drought stress. It seems that Lutea and Bona cultivars have the highest drought tolerance in germination stage.