نشریه علوم و تحقیقات بذر ایران
سال نهم شماره 4 (زمستان 1401)

In order to study effect of planting date and seed priming on some morphological characteristics, sugar yield and yield sugar yield components of sugar beet (Beta vulgaris), An experiment was conducted on a farm land in Mahabad city at 2020 growing season. The experiment design was split plot based on randomized complete block with four replications. planting date (March 5, April 3 and May 4) assigned to main plots, and priming types (Salicylic acid, hydropriming, chitosan and control (no priming)) assigned to sub plots. In this study, the traits of chlorophylla and chlorophyllb content, carotenoids, relative leaf water content sugar content, white sugar content, root yield, sugar yield and white sugar yield were measured. In this study, the highest content of chlorophyll a, chlorophyll b, carotenoids, leaf area index, was allocated to the March 5th planting time. Also, salicylic acid priming and hydropriming had the highest content of chlorophyll a, chlorophyll b, carotenoids, leaf area index. Among the interactions of planting time with priming treatments, the highest relative water content of leaves (75.50%) , root yield (60.1 t / ha), sugar content (19.49), white sugar content (15.02), sugar yield (10.91 tons per hectare) and white sugar yield (8.31 tons per hectare) were allocated to April 3 planting time and priming with salicylic acid.The results also showed that salicylic acid priming and hydropriming at all planting times increased the white sugar yield compared to the control treatment and moderated the adverse effect of delay at planting time on the white sugar yield.

Pelleting is done by adding inert adsorbents to change seed size and shape and improve seed yield and plant ability. This present study was conducted to investigate potato minituber pelleting (Agria cultivar) to improve some key potato traits in a randomized complete block design with three replications in the research farm of Mohaghegh Ardabili University in 2018-2019. Experimental treatments included 9 different combinations of Arabic gum or cellulose adhesive, zeolite or cocopeat fillers and chitosan with control treatment (without pellets). The studied traits were leaf number of leaves, fresh yield, dry matter yield of potato tuber, leaf stomatal conductance, tuber carbohydrate content, tuber density and chlorophyll content in leaves. The results showed a significant effect of potato minituber pelleting on traits such as Number of leaves, Fresh and dry matter yield of potato tubers, leaf stomatal conductance, tuber acidity, density and chlorophyll b content. Pelleting of minitubers with Arabic gum + zeolite + chitosan had the highest number of leaves and density of potato tubers it showed an increase of 50.88 and 15.9 percent, respectively to the control treatment. According to the results, the highest fresh yield and dry matter yield of potato tuber were obtained in the treatment of Arabic gum with zeolite, which showed an increase of 47.14 and 39.46 percent, respectively, compared to the control. The highest amount of leaf stomatal conductance was observed in the cellulose adhesive + cocopeat treatment combination, which resulted in a 70.21% increase compared to the control treatment. The highest amount of chlorophyll b in cellulose adhesive + cocopeat + chitosan treatment combination showed an increase of 42.7% respectively, compared to the control treatment. In general, in terms of quantitative traits, application of Arabic gum with zeolite along with chitosan led to the improvement of most morphological, functional and physiological traits.

Infected seeds play considerable role in establishment of bacterial leaf streak disease caused by Xanthomonas translucens on cereal, which can onset disease outbreaks under favorable environmental conditions. The population of this pathogenic bacterium fluctuates over time in the seed. The present study investigated these changes and their effects on the disease establishment and seed quality. The bacterial population in the seeds harvested from the infected fields with progressed symptoms up to the flag leaves, had at least 104 to a maximum of 4×105 CFU/gr at harvest time. Ten months later the population was reduced to 102 to a maximum of 4×104CFU/gr and 24 months after harvest, the pathogen was not isolated from the seeds (except for one sample). The seed contamination evaluated in this study is higher than the seed contamination threshold (103CFU/gr) but disease transmission in the experimental field occurred from zero to a maximum of one percent. Although this rate of transmission is low, the same number of diseased plants in favorable environmental conditions can trigger an epidemic. Also, bacterial population on seed even after storage time did not have significant effects on germination and natural seedlings emergence, although on some characteristics related to longitudinal growth had significant effects. The effect of X. translucens on physiological and biochemical changes of seeds needs to be further investigated.

The sustainability of landscapes, especially in arid and sub-tropical areas with limited water resources, requires the use of suitable plants and adapted to the climatic conditions of these areas. Therefore, the study of species tolerant to salinity and drought stress for the construction of landscapes with the approach of optimal use of water resources and increase its productivity, the study of plants tolerant to drought and salinity stress is important. This study was performed to investigate the effects of salinity and drought stress on germination of four turfgrass species. In order to investigate the effects of drought stress (0, -2, -4, -8 and -16 Bar) and salinity (0, 2, 4, 8 and 16 dS/m) on four species of warm-season turfgrass (Buchloe dactyloides, Cynodon dactylon, Zoysia japonica and Paspalum vaginatom) were two separate experiments designed and performed in a completely randomized design with four replications in the Horticulture Physiology Laboratory of Agricultural Sciences and Natural Resources University of Khuzestan in 2020. The results showed that in conditions without stress and moderate salinity and drought stress, there was no difference between the four studied tropical grass species in terms of the studied characteristics, while in severe salinity and drought stresses, P. vaginatom ratio It excelled in three other ways. P. vaginatom had the highest germination rate with an average of 3.8 and 4.6 per day in the most severe drought and salinity levels. Also, in severe salinity and drought stress, B. dactyloides had the lowest percentage and germination rate, the lowest root and stem growth. Analysis of alpha-amylase activity among different species and salinity and drought stress showed that the highest activity of this enzyme was observed in all species at the control level (without stress). Alpha-amylase activity was lower in B. dactyloides at all levels than in other species. Also in severe levels of species strain P. vaginatum showed higher activity of alpha-amylase enzyme. Therefore, it will give it a better chance to establish the plant and start exploiting the facilities of the environment in conditions of drought and salinity stress.

To evaluate the effect of salinity and temperature on germination, seedling growth, and ionicrelations in Castor a factorial experiment in a completely randomized design with four replications was conducted. Treatments consisted of salinity (zero, 25, 50, 100, 200, and 400 mM NaCl) and four temperature levels were 15, 20, 25, and 30 degrees Celsius respectively. In this study, germination percentage, germination rate, average germination time, root and shoot length, root and shoot dry weight, root to shoot weight ratio, shoot and root sodium, shoot and root potassium and the ratio of sodium to potassium was measured. By the increasing salinity levels, all germination indices decreased but salinity increased Root to shoot ratio and Germination time. Results showed that 20 °c had the highest germination rate, root length, shoot length, root fresh weight, shoot fresh weight, shoot dry weight, root, shoot dry weight, plant height Compared with other treatments. In this study, with increasing salinity level, the amount of shoot sodium, root sodium, and the ratio of sodium to potassium was increased. Also, the amount of potassium in roots and shoots decreased simultaneously. The temperature of 20 ° C had the lowest shoot and root mean germination time allocated shoot to root ratio and mean germination times. With increasing levels of salinity, the sodium content of shoot, root sodium, and sodium to potassium ratio was increased. Also, amount of potassium in roots and shoots increased by Increasing salinity levels, With increasing temperature amount of potassium reduced and sodium was increased

High temperatures causes serious damage to plants, including disruption of cell hemostasis, slowness or stagnation of growth and development, and even death. When plants are exposed to high temperatures, heat shock proteins (HSP) are induced in the cell. Among HSPs are Small heat shock proteins (sHSP), which act as chaperones. They bind to proteins that have been exposed to heat stress and prevent them from incorrectly folding. The Artemin protein isolated from Artemia urmiana has a a-crystallin domain, which is characteristic of sHSP. In order to characterize the functional genomic roles of the protein in plants, artemin gene was transferred to Arabidopsis. A statistical analysis using the factorial design method was performed including two independent transgenic genotypes (art-1 and art-2) along with a wild genotype Col-0 under heat stress at 45°C. Results showed that the interaction between heat stress factors and genotypes was significant at the 1% level for most traits including germination, seedling wet and dry weight, seedling length, total protein content, catalase enzyme activity, and malondialdehyde content. All the components of germination were adversely affected by the application of heat stress. However, the transgenics still had a significantly higher seed germination and plant growth than the wild-type plants. As a result of heat stress, transgenic plants had significantly higher catalase enzyme activity and total protein content, and lower malondialdehyde levels compared with wild type plants. The results indicated that Artemin transgen in plants may cause significantly higher plant resistance to heat stress and increase plant yield.