محمدحسن جعفری صیادی

Garlic has the second rank in Allium species in the case of highly used plant species after onion with high nutritional and medicinal values. Garlic is a vegetative product and is contaminated by many pathogens and viruses. Meristem culture is an in vitro bulblet production method for removing the viral diseases. The purpose of this study is to evaluate effect of growth regulators on micropropagation and bulblet formatiom in local clones of garlic in Hamedan province by meristem culture. This research was done as a factorial experiment in a completely randomized design with ten clones and four growth regulators including: MS, MS+1µM BA, MS+1µM BA+1µM NAA and MS+10µM BA+5µM NAA. After the first stage and plantlet production, a factorial experiment in a completely randomized design with 10 clones and 4 hormonal treatments was used in MS medium containing 6% sucrose with three replications. The cultured samples were placed in a refrigerator at a temperature of 4 ° C for four months and then transferred to the growth chamber with 25ºC temperature and photoperiod of 16/8 h (day/night). A month later, take notes of samples. In order to normalize the data logarithmic transformation and uniformity test of variances were used and then Data were analyzed by SAS software and the meanings were compared using Duncan's test. In the first experiment, the use of growth regulators in the culture medium causes significant changes in the production seedling growth characteristics. MS + 1μM BA medium produced the highest seedling weight and leaf length. Garlic clones significant difference in the number of leaves, leaf length and weight of seedling showed. Sheverin clone highest number of leaves, leaf length and the maximum weight the seedlings produced. Interaction between hormonal treatments in clones was not significant for any of the studied traits. In the second stage of the experiment, the interaction of clones in hormonal treatments was significant at 1% level for all traits (plantlet weight, Bulblet weight, Bulblet number, Root weight and Leaf weight). Sheverin clones in MS + 10μM BA + 5μM NAA were highest in all studied traits. totally, the results of this research showed that we can identify the responces of the top clones of the garlic province of Hamedan in meristem culture. Also we achieved the suitable concentration and combination of plant growth regulators on regeneration of different clone garlic in vitro conditions. As a result, a better protocoles were introduced for micropropagation and bulblet formatiom of the garlic in tissue culture.

In order to evaluate the effects of pigweed (Amaranthus retroflexusL.)on growth properties of cotton (gossypium hirsutum), this research was conducted in Agriculture and Natural Resources Research Center of Tehran province in 2014. Field trial was based on randomized complete block design with 9 treatments (consisting of three Amaranthus retroflexus emergency times coincide with cotton cultivation, two-leaves and four-leaves of cotton and three plant densities including (3, 6 and 12 Amaranthus retroflexus per square meter) in three replications. The results showed that all cotton quantity properties consisting of plant height, number of sympodia and monopodia, height and lenght of the first sympodia, leaf area index, leaf and stem biomass, number and weight of boll, and cotton yield in all treatments reduced compared to control treatment (cotton cultivation). The difference among treatments was significant in all traits except quality traits at the level of 1% so that emergence of pigweed coincide with cotton emergence by density of 12 plant pigweed, Morphological traits and cotton yield decreased. Due to the significant reduction in cotton yield in the presence of weed compared to conrol treatment,consideration of Amaranthus retroflexus time weeding is mandatory. Considering that the highest cotton yield reduction was related to plant density of 12 pigweed and coinciding germination of pigweed with cotton cultivation time, it is necessary weed control of pigweed from the beginning growth season and timely weeding at sowing time before formation of boll

To study the effect of gibberellic acid and cold shock on dormancy breaking of potato minitubers Var. Agria, a factorial experiment based on completely randomized design with four replications was used. Studied factors included: 1. Gibberellic acid (1000 ppm and Control) and 2. Cold shock at 2°C (C1: no cold, C2: a week of cold, C3: two weeks of cold, C4: three consecutive weeks of cold, C5: three intermitant weeks of cold). Germination percentage, number of sprouts/minituber, length of sprouts,field establishment of minitubers and yield/unit area were studied. Results showed that GA significantly stimulated minitubers germination. In the case of 1000 ppm GA, the number of sprouts/minituber was the highest in all levels of cold shock, while in the absence of GA, cold shock significantly increased number of sprouts/minituber and this trait significantly reduced by prolonged cold period. GA significantly increased field establishment of minitubers. In the case of GA, number of produced tubers/unit area was not significantly different in cold shock levels while in the absence of GA, this trait significantly increased by prolonged cold shock.

Genetic resources are the most valuable national treasure of a country and it is vital to identify, conserve and use them. The Persian walnut (Juglans regia L.) is one of the most valuable genetic resource in Iran due to its multi benefits (nutrition, wood, environment conservation, genetics and medicine). For this reason, 32 leaf morphological characteristics of J. regia were studied on nine populations (four native and five cultivated) and 243 individual trees. Leaf sampling was made two years for the native populations and one year for the cultivated populations. The effects of year variation on leaf characteristics and the effects of leaflet numbers on wealth variation of the characteristics within each genotype were studied. The ANOVA analysis showed that there were significant differences between the walnut genotypes in respect to their leaf characteristics (P<0.001). After correction of variance coefficient (C.V.) of each genotype, based on deduction of corrected C.V. within genotype (C.V.G.) according toleaflet numbers (5, 7, 9 and 11 leaflets) from primary C.V., a high real value of C.V. was achieved. The Duncan method was used to compare the means and identify the less variable leaf characteristics, based on C.V.G. and correction of leaflet numbers. Correlation coefficient of leaf characteristics according toeach leaflet number groups (5, 7 and 9 leaflets) was investigated. Using cluster analysis (UPGMAmethod) to classify the 32 leaf morphological characteristics for the 243 trees, resulted in 19 clusterswhich seven clusters contained one individual members and four clusters contained double or triplemembers. The results showed that the most important, distinctive and reliable leaf morphologicalcharacteristics of J. regia were as follows: length of biggest leaflet, petiol length, leaflet marginal form,Arctangent of average leaflet length to average leaflet width, Arctangent of half leaf width to petiollength.