Piriformospora indica promotes growth, seed yield and quality of Brassica napus L.

In current scenario, crop productivity is being challenged by decreasing soil fertility. To cope up with this problem, different beneficial microbes are explored to increase the crop productivity with value additions. In this study, Brassica napus L., an important agricultural economic oilseed crop with rich source of nutritive qualities, was interacted with Piriformospora indica, a unique root colonizing fungus with wide host range and multifunctional aspects. The fungus-treated plants showed a significant increase in agronomic parameters with plant biomass, lodging-resistance, early bolting and flowering, oil yield and quality. Nutritional analysis revealed that plants treated by P. indica had reduced erucic acid and glucosinolates contents, and increased the accumulation of N, Ca, Mg, P, K, S, B, Fe and Zn elements. Low erucic acid and glucosinolates contents are important parameters for high quality oil, because oils high in erucic acid and glucosinolates are considered undesirable for human nutrition. Furthermore, the expression profiles of two encoding enzyme genes, Bn-FAE1 and BnECR, which are responsible for regulating erucic acid biosynthesis, were down-regulated at mid- and late- life stages during seeds development in colonized plants. These results demonstrated that P. indica played an important role in enhancing plant growth, rapeseed yield and quality improvement of B. napus.

[Visual Detection Study on Early Bruises of Korla Pear Based on Hyperspectral Imaging Technology].

In this paper, hyperspectral imaging combined with chemometrics was applied for the detection of internal defects of Korla pear. The hyperspectral images covering the spectral range of 380～1 030 nm were acquired for 60 Korla pears before, and seven consecutive days after internal damages were induced by being dropped from a distance of 30 cm. The mean spectrum were computed from region of interests (ROI) of pear in each image, and was preprocessed with wavelet transform for eliminating system noise and external disturbances, and optimizing the spectral identification region (470～963 nm). Based on the preprocessed samples, the support vector machine models were built respectively through the full and feature wavebands selected by the second derivative. The results on testing set demonstrate that both of the two approaches achieved the discrimination accuracy of 93.75%. Furthermore, F-value based method was applied for image analysis to find out the optimal waveband ratio for the visual discrimination of bruises against normal surface. Based on the optimal waveband ratio images, the selective search algorithm was utilized for segmenting bruises from the pear surface, and shows the accurate identification results. Our research revealed that the hyperspectral imaging technique for detecting bruised features in pears is feasible, which could provide a theoretical reference and basis for designing classification system of fruits in further work.

[Revealing the chemical changes of tea cell wall induced by anthracnose with confocal Raman microscopy].

Healthy tea and tea infected by anthracnose were first studied by confocal Raman microscopy to illustrate chemical changes of cell wall in the present paper. Firstly, Raman spectra of both healthy and infected sample tissues were collected with spatial resolution at micron-level, and ultrastructure of healthy and infected tea cells was got from scanning electron microscope. These results showed that there were significant changes in Raman shift and Raman intensity between healthy and infected cell walls, indicating that great differences occurred in chemical compositions of cell walls between healthy and infected samples. In details, intensities at many Raman bands which were closely associated with cellulose, pectin, esters were reduced after infection, revealing that the content of chemical compounds such as cellulose, pectin, esters was decreased after infection. Subsequently, chemical imaging of both healthy and infected tea cell walls were realized based on Raman fingerprint spectra of cellulose and microscopic spatial structure. It was found that not only the content of cellulose was reduced greatly after infection, but also the ordered structure of cellulose was destroyed by anthracnose infection. Thus, confocal Raman microscopy was shown to be a powerful tool to detect the chemical changes in cell wall of tea caused by anthracnose without any chemical treatment or staining. This research firstly applied confocal Raman microscopy in phytopathology for the study of interactive relationship between host and pathogen, and it will also open a new way for intensive study of host-pathogen at cellular level.

[Study on the early detection of Sclerotinia of Brassica napus based on combinational-stimulated bands].

The combinational-stimulated bands were used to develop linear and nonlinear calibrations for the early detection of sclerotinia of oilseed rape (Brassica napus L.). Eighty healthy and 100 Sclerotinia leaf samples were scanned, and different preprocessing methods combined with successive projections algorithm (SPA) were applied to develop partial least squares (PLS) discriminant models, multiple linear regression (MLR) and least squares-support vector machine (LS-SVM) models. The results indicated that the optimal full-spectrum PLS model was achieved by direct orthogonal signal correction (DOSC), then De-trending and Raw spectra with correct recognition ratio of 100%, 95.7% and 95.7%, respectively. When using combinational-stimulated bands, the optimal linear models were SPA-MLR (DOSC) and SPA-PLS (DOSC) with correct recognition ratio of 100%. All SPA-LSSVM models using DOSC, De-trending and Raw spectra achieved perfect results with recognition of 100%. The overall results demonstrated that it was feasible to use combinational-stimulated bands for the early detection of Sclerotinia of oilseed rape, and DOSC-SPA was a powerful way for informative wavelength selection. This method supplied a new approach to the early detection and portable monitoring instrument of sclerotinia.

[Identification and classification of rice leaf blast based on multi-spectral imaging sensor].

Site-specific variable pesticide application is one of the major precision crop production management operations. Rice blast is a severe threat for rice production. Traditional chemistry methods can do the accurate crop disease identification, however they are time-consuming, require being executed by professionals and are of high cost. Crop disease identification and classification by human sight need special crop protection knowledge, and is low efficient. To obtain fast, reliable, accurate rice blast disease information is essential for achieving effective site-specific pesticide applications and crop management. The present paper describes a multi-spectral leaf blast identification and classification image sensor, which uses three channels of crop leaf and canopy images. The objective of this work was to develop and evaluate an algorithm under simplified lighting conditions for identifying damaged rice plants by the leaf blast using digital color images. Based on the results obtained from this study, the seed blast identification accuracy can be achieved at 95%, and the leaf blast identification accuracy can be achieved at 90% during the rice growing season. Thus it can be concluded that multi-spectral camera can provide sufficient information to perform reasonable rice leaf blast estimation.

Molecular identification of cDNA, immunolocalization, and expression of a putative odorant-binding protein from an Asian honey bee, Apis cerana cerana.

An odorant-binding protein cDNA (Acer-ASP2) was cloned and characterized from antennae of adult workers of an Asian honey bee, Apis cerana cerana F. (Hymenoptera: Apidae). The full-length open reading frame of Acer-ASP2 cDNA was 429 bp, encoding 142 amino acids. Protein signature analyses revealed that it contained six conserved cysteines with an N-terminal signal sequence of 19 amino acids. The deduced protein sequence shares high homology with Amel-ASP2 from the honey bee, Apis mellifera L., and low similarity with odorant-binding proteins from other species of insects. Immunocytochemical localization showed that Acer-ASP2 was concentrated in the lymph of olfactory sensilla, such as sensilla placodea and sensilla trichodea A. Real-time polymerase chain reaction of Acer-ASP2 transcripts showed that Acer-ASP2 was expressed on antennae but not in other general anatomical regions of the body. Temporally, Acer-ASP2 was expressed at a relatively high level in adults during two periods (9 and 27 vs. 1, 15, and 30 days). This timing is correlated with the production of beeswax and searching behavior for nectar/pollen, respectively. Thus, Acer-ASP2 is a species-specific gene that we propose to be involved in the acquisition of odorant molecules from nectar, pollen, and other general odorant sources.

Keratinase production and keratin degradation by a mutant strain of Bacillus subtilis.

A new feather-degrading bacterium was isolated from a local feather waste site and identified as Bacillus subtilis based on morphological, physiochemical, and phylogenetic characteristics. Screening for mutants with elevated keratinolytic activity using N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis resulted in a mutant strain KD-N2 producing keratinolytic activity about 2.5 times that of the wild-type strain. The mutant strain produced inducible keratinase in different substrates of feathers, hair, wool and silk under submerged cultivation. Scanning electron microscopy studies showed the degradation of feathers, hair and silk by the keratinase. The optimal conditions for keratinase production include initial pH of 7.5, inoculum size of 2% (v/v), age of inoculum of 16 h, and cultivation at 23 degrees C. The maximum keratinolytic activity of KD-N2 was achieved after 30 h. Essential amino acids like threonine, valine, methionine as well as ammonia were produced when feathers were used as substrates. Strain KD-N2, therefore, shows great promise of finding potential applications in keratin hydrolysis and keratinase production.