This study was carried out in Kathmandu valley, Nepal to document the fungal pathogens associated with the worst invasive species Ageratina adenophora and Parthenium hysterophorus . Pathogen infected leaves were collected in the fields and were cultured in the PDA media. The pathogenic fungi were isolated and identified. Eleven fungal pathogens, namely Alternaria sp., Fusarium sp., Cercospora partheniicola , Colletotrichum capsici , Curvularia sp., Passalora ageratinae , Chaetomium anguipilium , Cladosporium cladosporoides, and Puccinia abrupta var. partheniicola were found on Parthenium hysterophorus . In contrast, Passalora ageretinae and Cladosporium cladosporoides were found on Ageratina adenophora . Curvularia lunata was seen on both the invasive plant species.
Soil contamination can be addressed through phytoremediation technique which is one of the most important environmental problem. A pot study was conducted to examine the phytoremediation of anthracene and pyrene contaminated soil by Lolium perenne plant species for 45 days. The ability of Lolium perenne to remediate anthracene and pyrene spiked soil with initial concentration of 81.6 and 71.3 mg/kg was accessed. The anthracene and pyrene concentration in unplanted control soil on day 20 was 62.1 and 59.2 mg/kg respectively, whereas the respective concentration of unplanted control soil on day 45 was 21.7 and 22.4 mg/kg respectively. Lolium perenne was more effective in anthracene and pyrene removal from contaminated spiked soil during 45 days experiment. The results demonstrate the enhancement in disappearance of anthracene and pyrene by Lolium perenne on day 20 was 42.4 and 45.9 mg/kg, respectively, while there is complete removal of anthracene and pyrene by Lolium perenne was observed on day 45. The results
An attempt was made to examine the effect of varied concentrations and combinations of phytohormones on morphogenic response of four citrus cultivars viz., Rough lemon (C. Jambhiri), Kinnow (C. reticulata), Feutrell‘s early (C. reticulate × C. sinensis) and Musambi (C. sinensis) from shoot tip explants. To achieve in vitro shoot regeneration, in vitro maintained healthy shoot tips of four cultivars were excised and positioned on modified MS (Murashige and Skoog, 1969) medium fortifying the following benzylaminopurine (BAP)/Indole acetic acid (IAA) concentrations: 0.5/0.4, 1.0/0.4, 1.5/0.4, 2.0/0.4 and 2.5 mg L-1/0.4 mg L-1. Synergetic effect of BAP with IAA was best found on MS medium containing 1.0/0.4 mg L-1 concentration of BAP to IAA for shoot number/plant (2.25), shoot length (2.52cm) and leaf number/plant (10.58). The shoot multiplication rate was decreased in all four cultivars when BAP concentration was increased from 1.0-2.5 mg L-1. In order to assess the impact of different concentrations of auxins, well proliferated shoots were shifted to the rooting medium ((MS micro & macro elements, 100 mg L-1 myo-inositol, MS vitamins, 2 mg L-1 glycine, 30 g L-1 sucrose and 7.0 g L-1 agar) augmented with varied naphthalene-1-acetic acid (NAA)/ indole-3-butyric acid (IBA) concentrations i.e. 0.5/0.3, 1.0/0.3, 1.5/0.3, 2.0/0.3 and 2.5/0.3 mg L-1. Regenerated shoots started to rooting within 22.25 days, had more number of roots/plant (4.25) and root length (3.35cm) on medium containing 1.0 mg L-1 NAA and 0.3 mg L-1 IBA. Sub or supra optimal concentrations of phytohormones resulted in low plant regeneration in all the four cultivars assessed. It was also found that the morphogenic response was genotype dependent in citrus cultivars
Seeds of four wheat BARI Gom varieties were irradiated with four different doses of Gamma rays (150Gy, 200Gy, 250Gy, 300Gy). Both M 1 and M 2 population were exposed to wheat blast under natural field condition. In the present study, M 3 seeds harvested off M 2 population were grown under both confined inoculated and natural field condition. In BINA campus, M 3 plants were inoculated with spore load (CFU 1×10 7 spores/ml) of Magnaporthe oryzae Triticum (MoT) at pre-heading stage (53 days age). Inoculation was repeated thrice to cover pre-heading stage of some late mutants. In Madnadanga Meherpur Sadar, M 3 population was exposed to blast infection under natural field condition in the farmer’s field. Among the radiation doses, 200Gy produced significant reduction in MoT infection. Inoculated M 3 plants showed differential reaction to Magnaporthe infection. Only one entry (BWM 5) was completely free of blast infection. Another one entry (BWM 6) carried only 0.13 % blast severity. Eight entries (BWM 2, 3, 7, 9, 20, 21, 22, 23) had <5% blast severity while other four entries had< 10% blast severity. Here blast severity means percent spike surface area bleached. Molecular analysis in PCR done with MoT3 marker produced typical bands of MoT (361 bp) in all the entries except for the entry BWM 5. In Madnadanga farmer’s field, blast disease pressure was very low; most of the entries did not catch infection. Entry BWM 5 and entry BWM 6 and some other 12 entries which showed 0-10% blast severity indicated the inheritance of blast resistance which needs advancing through further checking under inoculated epiphytotic condition.
Mycotoxin s are secondary metabolites produced by fungi, which are harmful to humans and animals. Phoma is a common fungal plant pathogen that can produce mycotoxins in sugarcane. Phoma sorgina belonging to phoma species that cause devastating fungal disease twisted leaf on sugarcane, The present study helps to carry out research on potential metabolites of fungal strain belongs to the phoma sorghina species such as P. sorghina (BS2-1), P. sorghina (BS11-1), P. sorghina (BSQP) isolated from sugarcane. These metabolites may influence the functioning of the fungus and are thus important indirectly for its growth and survival. Mass spectrometry (MS) is commonly used for the detection, characterization and quantitation of mycotoxins in agricultural crops. Phoma species were assessed to provide a risk assessment of their secondary metabolites in sugarcane by describing their global metabolome data obtained from the LC-MS instrument. Another study examined through using matrix-assisted laser desorption ionisation – time of flight mass spectrometry (MALDI-TOF MS) to identify phoma species rapidly and accurately. Different protein mass spectra obtained with MALDI-TOF MS were able to separate the phoma species reported in sugarcane. Therefore, the discovery of new conjugated mycotoxins and secondary metabolites produced phoma species was made possible by combining high mass accuracy data with analytic approaches.
