Iranian Journal of Seed Science and Research
Year:2014 | Volume:1 | Issue:2|Papers Count:6

In order to study the effects of seed wheat inoculation with VA mycorrhiza and azotobacter bio fertilizers on reduction of late season drought stress damage, an experiment was conducted in agricultural and natural resources research center of Tehran province on 2011-12. Four levels of seed inoculations (non-inoculation, inoculation with VA mycorrhiza fungus, inoculation with azotobacter and combined inoculation (fungus plus bacteria) in a randomized complete block design with three replications were evaluated. Another same experiment (same treatments, same soil type and same planting, cultivation and harvest condition), but in drought stress environment (non-irrigation at start of flowering stage) conducted. Drought stress at start of flowering stage caused a significant decrease by 21.3% on grain yield from 7763 to 6108 kg/ha that was mainly due to significant reduction of number of seed per spike, number of fertile tiller, biological yield and TKW. Seed protein percentage and seed phosphorus percentage increased at stress condition but this was significant only for protein percentage. Effect of seed inoculation with bio fertilizers was significant for all traits except harvest index. All three levels of inoculation increased wheat grain yield significantly, but the positive effect of mycorrhiza was more than the others. The difference between seed inoculation with each one of micro organisms and dual inoculation was not significant. The amount of grain yield for S2I1 treatment (drought stress condition and without inoculation) was 5437 kg/hac, but inoculation with mycorrhiza (S2I2), azotobacter (S2I3) and dual inoculation (S2I4), increased the grain yield to 6463, 6129 and 6403 kg/hac respectively. Protein yield and percentage and phosphorus yield and percentage increased significantly for all three inoculation treatments. Drought stress effect on RWC was not significant but seed inoculation had a significant effect on RWC.

In this study, soybean seeds (cv. Katool) were collected randomly from fields in the various parts of Golestan province, including Bandargaz, Kordkuy, Gorgan, AliAbad, Azadshahr and Kalaleh. To recognize the seed borne fungi, soybean seeds were plated on acidified potato dextrose agar acidified medium (pH=4.5). After identification of fungal pathogens, seed germination test were carried before and after accelerated aging to determine seed quality. A total of four genera of seed borne fungies were identified in different regions of this province. Incidence rate of These four pathogens that included Alternaria sp., Fusarium sp., Phomopsis sp., and Cercospora sp., were very different in distinctive regions of the province. The most and least of fungual infections in seeds of the province produced by Alternaria sp. (22%) and Cercospora sp. (6.07%), respectively. Total fungal infections in seeds of Kordkuy (71.33% of the total seeds) were more than the other regions. The least seed infection (7.33%) were observed in seeds of Kalaleh. With the exception of Alternaria sp., other fungies reduced seed germination and vigor in the some areas. The fungus Phomopsis sp. was much more important than the other fungies. As, in all areas that seed infection by Phomopsis sp. were high (Bandargaz, Kordkuy and Gorgan), a seed germination and vigor decreased linearly. Due to the high amount of fungal infections of soybean seeds in Golestan province, and negative impact of these pathogens on seed germination and vigor, Researchers and seed producers inform about the type and incidence of fungies in each of these areas, and efforts to find appropriate solutions and adapted to areas for control and reduce the negative effects of pathogens on seed quality characteristics, will be cause for increasing of health and efficiency of agricultural ecosystems in the province.

Seeds have many different adaptions for dispersal. Seed morphology has an important role in the type and amount of seed dispersal. The aim of this study was to examine some morphological characteristics of seeds, seed persistence in the soil and their dispersal mechanisms for 29 species in Kelardasht rangelands in Mazandaran province, Iran. The seed length, seed width and thickness were determined using a digital caliper with an accuracy of 0.01 mm. These dimensions were used to calculate seed shape. Seed color and some features of seed surface were studied using binoculars and published references. Seed germination as a quantitative parameter also was measured in laboratory. Seed length varied between 1.10 for Trifolium arvense and 4.43 for Calystagia sepium. The minimum and maximum widths of seeds were 0.71 and 6.97 mm, respectively for Plantago major and Heracleum persicum. The maximum seed thickness was found for Calystagia sepium with 3.27 mm and the minimum for Lactuca serriola with 0.38 mm. Seed shape ranged between 0.015 to 0.17 mm. The results showed that seed longevity was not significantly correlated with seed shape and seed size. Dispersal mechanisms by animals, human activity and wind have the most effect on seed dispersal in Kelardasht.

In order to evaluate the allelopathic effects of shoot and root water extract of wild mustard (Sinapis arvensis) on germination properties and seedling growth of wheat cultivars, an experiment was conducted in factorial based on completely randomized design with three replications at the physiology laboratory of Golestan Agriculture and Natural Resources Research Center, Iran in 2011. Experimental treatments were different consentations of water extract of shoot and root Wild mustard (0, 2.5, 5 and 7.5%) and wheat cultivars (Morvarid, Moghan, Tajan and Arta). Also, in order to separate the osmotic effects of different concentrations of wild mustard water extract from allelochemicals effects, the polyethylene glycol 6000was used. The results showed that with increasing the concentration of shoot and root water extract of wild mustard, percentage and rate of germination, shoot and root length, shoot and root dry weight and seedling dry weight of different wheat cultivars decreased significantly., and it was different among the wheatvcultivars, whereas in the highest concentration, Moghan and Morvarid cultivars showed the least influence and Tajan and Arta cultivars showed the highest influence. Furthermore the different concentrations of polyethylene glycol had no effect on the traits mentioned above. This confirms that the osmotic potential of extracts had no influence in intensifing of allelochemicals effects. Fitting of three-parameter logistic model provided a successful estimation of the relationship between different levels of water extract and germination percentage. Generally, wild mustard shoot showed more inhibitory effect than the root.

Positive and beneficial effects of mycorrhizal symbiosis on growth of different plants have been demonstrated in the past. These fungi by creating a symbiotic relationship with the roots of plants leads to improved morphological and physiological characteristics and are balancing on soil biodiversity. Most of the crops are capable of establishing symbiosis with endo-mycorrhizal fungi, but so far, no study has been done on the possibility of establishing a symbiotic relationship between these fungi and lily. For this purpose, this study was performed to investigate the effect of different species of mycorrhizal fungi, including Glomus intraradices, Glomus etunicatum, Glomus mosseae and Glomus clorum on yield of Lily longiflourm and Lily ledebourii. This research carried out as a factorial in a Completely Randomized Design with three replications. The results showed that the root of L. longiflourm and L. ledebourii has developed a symbiosis at an acceptable level and the interaction of mycorrhiza on two species of lily is significant on investigated traits. The highest of root colonization percentage was observed in L. longiflourm inoculated with G. etunicatum, while, there was the lowest of root colonization percentage in L. ledebourii inoculated with G. clorum and L. ledebourii without inoculation. Also, the highest and lowest of plant height was observed in L. longiflourm inoculated with G. etunicatum and L. ledebourii without inoculation, respectively. Interaction effect of lily×mycorrhiza showed the highest absorption of phosphorus, iron and zinc was observed in L. longiflourm and L. ledebourii inoculated with G. etunicatum. Actually, the results of this study indicate to affect symbiotic of G. etunicatum on growth and nutrients uptake that provides background to investigate the feasibility of its application to improve plant growth in lily.

Nowadays, the use of biofertilizer is steadily increasing in sustainable agriculture, therefore the present study was aimed to evaluate the effect of seed biopriming by Piriformospora indica and Trichoderma virens on the growth, morphological and physiological parameters of mung bean (Vigna radiate L.). Experiment was conducted as completely randomized design with three replicates in 2014. Treatments were included four levels of biopriming (control, inoculation by P. indica or T. virens and dual inoculation by P. indica and T. virens). Seeds of mung bean were sown in sterile soil and grown for four weeks and then some morphological, growth and photosynthetic pigments parameters were determined. Results showed that seed biopriming by Trichoderma, P. indica and dual inoculation increased plant height (4, 8 and 2 %, respectively) and root length (18, 31 and 13%, respectively) as compared to the uninoculated control. However, the increase was significant only for P. indica inoculated seeds. Furthermore, shoot fresh and dry weights increased when mung bean seeds inoculated by both fungi. The maximum increase in stem, shoot and plant dry weights (5, 3 and 2 times of control) were recorded when seeds inoculated with P. indica. Also, inoculation of seeds by P. indica improved chlorophyll a, b, a+b contents (nearly 8, 15 and 9 %, respectively). In conclusion, it seems that seed biopriming of mung bean by growth promoting fungi particularly P. indica positively improved the growth attributes in early growth stages.