Effects of different treatments on seed germination and breaking seed dormancy of <Emphasis Type="Italic">Prosopis koelziana</Emphasis> and <Emphasis Type="Italic">Prosopis Juliflora</Emphasis>

For improving seed germination of Prosopis koelziana and Prosopis juliflora, different treatments of seeds were conducted, including scarification with sulfuric acid 98% for 10 and 15 min, sandy paper, hot water for 5 and 10 min, potasium nitrate 0.1%, gibberellic acid at 250 mg·L⁻¹ and 500 mg·L⁻¹ and combinational treatment of scarification with gibberellic acid of 250 mg·L⁻¹ and 500 mg·L⁻¹. The results show that scarifications with sandy paper and sulfuric acids 98% were the most effective treatments on breaking seed dormancy and seed germination induction. Scarification with sulfuric acid 98% for 15 min was the best treatment. According to the positive effect of scarification and lack of reaction of seeds against KNO₃ and gibberellic acid, the kind of seed dormancy was determined as exogenous.     

Symptoms and fungi associated with elm trees decline in Iran

Elm (Ulmus, Ulmaceae) is one of the most popular and important trees in urban and landscape areas in Iran. A severe decline of elm trees has recently been observed in some areas of Kerman and Shiraz cities. However, the identity of the causal agents has not yet been investigated. The purpose of this study, carried out in the years 2012–2014, was to isolate and identify fungal trunk pathogens associated with decline symptoms observed in elm trees. Samples were collected from trunks and branches of trees showing various disease symptoms and internal wood lesions. Fungal isolations were made from discolored or decayed wood tissue. In Kerman some elm trees were attacked by the beetle Aeolesthes sarta; therefore, samples were also collected from larvae and adults of beetles associated with trees showing wood damage. Fungal isolates were identified by morphological, cultural and molecular characteristics. Thirteen fungal species, Phaeoacremonium (P.) minimum, P. parasiticum, P. sicilianum, P. alvesii, P. fraxinopennsylvanicum, Spencermartinsia viticola, Dothiorella (Do.) sarmentorum, Neoscytalidium hyalinum, Diatrype (Di.) whitmanensis, Cosmospora viridescens, Phoma (Pho.) herbarum, Phellinus (Phe.) tuberculosus and Inonotus levis were identified. Phaeoacremonium parasiticum was the only species isolated from both larvae and adult beetles. Pathogenicity trials were performed on detached shoots of elm under greenhouse conditions. Dothiorella sarmentorum was the most virulent species based on the length of wood necrosis. This study is the first report of P. sicilianum, C. viridescens and Phe. tuberculosus in Iran. In addition, most of the isolated species are reported for the first time on elm trees in the world.     

Over-mature beech trees (Fagus orientalis Lipsky) and close-to-nature forestry in northern Iran

Oriental Beech is the most important commercial tree species in northern Iran. In recent years wood production companies interested in felling large beech trees for profit have challenged advocates of close-to-nature silviculture who favor conservation. Our study objective was to assess the economic value of over-mature beech trees by relating tree diameter (DBH) to amount of decay. Based on the location of onset of decay, we categorized three types of decay as stump, stem, and crown decay. Trees of greater diameter (age) typically showed greater decay in the stem. Percent of decayed volume, diameter of decayed tissue, and length of decay in tree stems varied between 0.5%?64.3%, 15 cm?75 cm, and 2.0?19.5 m, respectively. With increasing trunk diameter, the proportion of truck decay increased. Red heart and dark red heart constituted 25% and 14.3% of sampled trees, respectively. However, we found no correlation between intensity of stem decay and morphological characteristics of trees. Seedlings were not abundant around the bases of over-mature trees, suggesting that the trees did not contribute to regeneration of the stand. Beech trees of diameter >1 m do not provide valuable round wood for industries and cause to raise wood production costs. We recommend that these trees >1 m DBH should be retained in forest stands because of their low commercial value but high ecological and conservational values such as maintaining biodiversity in forest ecosys-tems.     

Small-scale Agar (Aquilaria agallocha Roxb.) Based Cottage Enterprises in Maulvibazar District of Bangladesh: Production, Marketing and Potential Contribution to Rural Development

Globally, trade in agar-based products is growing rapidly due to their recent adoption as an ingredient in the cosmetics and pharmaceuticals sector. In Bangladesh, people living in some north-eastern districts have been engaged in the production, processing and trading of such products for several decades. These practices, which they consider as the lifeblood of their existence, have been inherited from their ancestors. This paper reports a case study carried out in Maulvibazar district exploring the production and marketing, and industry problems, of agar-based enterprises and their potential contribution to socio-economic development. An exploratory survey was undertaken over 30 randomly selected agar-based factories during December 2005–April 2006, with entrepreneurs of the factories personally interviewed using a semi-structured questionnaire. The majority of the factories of the area were found to depend on local sources of raw materials to produce agar-based products. About 514 full and part-time workers are employed in the factories. Average annual expenditure, revenue and net annual income per factory for three consecutive years 2003–2005 of the study were estimated as Tk 63,980, Tk 111,414 and Tk 47,435, respectively, being highest where attar (agar oil) of superior grade was produced for export. There appears to be a sustainable source of raw materials, availability of technical and financial assistance and opportunity for expansion of market facilities to secure the maximum benefit achievable from this highly promising industry.

海栖热袍菌极端耐热木聚糖酶B的提纯

克隆并在大肠杆菌中表达的海栖热袍菌的 xyn B基因 ,其表达产物木聚糖酶 B的 C 末端带有 6×His标签 ,研究了这种基因重组酶的提纯方法。通过对粗酶提取液的热变性处理 ,Ni NTA亲和柱层析和离子柱层析 ,最终得到了电泳纯的木聚糖酶 B,提纯倍数 4 4.4 ,得率 11。SDS PAGE法测定木聚糖酶 B的相对分子质量为 4 2 ku,与理论推算值 4 2 333u相吻合     

Ameliorative effects of spermine application on physiological performance and salinity tolerance induction of susceptible and tolerant cultivars of wheat (Triticum aestivum)

Polyamines are well known in environmental stress tolerance induction of plants. The present study was conducted to evaluate the interactive effects of salinity (0, 100 and 200 mM NaCl) and spermine (Spm) concentration (0, 0.5 and 1 mM solution) on physiological performance of susceptible (Sepahan) and tolerant (Neyshabour) wheat cultivars. Proline accumulation was more affected by salinity than Spm. Chlorophyll a and b content was totally improved by Spm application. Catalase and ascorbate peroxidase (APX) activity was generally increased by increasing salinity and Spm level. Highest APX activity was observed on 200 mM salinity and highest level of Spm concentration in both tolerant and susceptible cultivars. Superoxide dismutase activity was elevated with increasing salinity level and applied Spm concentration in both cultivars. Higher levels of Spm under salinity conditions showed higher activity of glutathione reductase (GR) compared with the treatment without Spm, but it reduced GR activity under normal condition. Spm application decreased sodium content in all salinity levels in both cultivars, but not with a similar trend. Higher concentration of applied Spm also enhanced potassium content. To sum up, Spm application alleviated hazardous effects of salinity stress mainly through antioxidative defense and this was more evident in tolerant cultivar.     

Prevalence of avian influenza,Newcastle disease,and infectious bronchitis viruses in broiler flocks infected with multifactorial respiratory diseases in Iran, 2015–2016

In this study, the prevalence and spatial distribution of Newcastle disease, infectious bronchitis, and avian influenza have been evaluated in commercial broiler farms in 31 provinces in Iran. In this survey, a total of 233 affected broiler chicken farms were sampled. The infectious bronchitis virus (alone) was detected with highest frequency in 60 farms, and separately or combined with other agents, in 110 farms; Newcastle disease virus, separately, was detected in 28 farms, and in 63 farms separately or combined with other infectious agents; and avian influenza H9N2 was detected in 22 farms separately and in 51 farms separately or concomitant with other infectious agents. The sample tested negative for all H5 serotypes. The results of the present study show that the most prevalent avian viral infectious disease contributing to respiratory syndromes in broiler farms in Iran was infectious bronchitis due to infectious bronchitis virus serotypes variant 2 and 793/B. On the other hand, combined with the alternation of dominant viruses and circulating strains, flocks are exposed to unremitting anamorphic viral infections. Thus, the permanent monitoring of cases that have occurred and the review of vaccination plans of affected flocks every year are some of the necessary measures needed for strategic control of respiratory syndrome in broilers. It is noteworthy that execution of epidemiologic examinations on the cogent factors of prevalence of this syndrome and defeat of vaccination strategy in the flocks is urgent and has to be fulfilled on the definite causes of time.