To ascertain the genotypic difference of cadmium tolerance of different varieties of maize, effects of cadmium stress on the germination rate, germination index, vigor index, root length and fresh weight, and shoot le...To ascertain the genotypic difference of cadmium tolerance of different varieties of maize, effects of cadmium stress on the germination rate, germination index, vigor index, root length and fresh weight, and shoot length and fresh weight of seeds of 12 main varieties of maize widely cultivated in central Hunan were studied. The results showed that the cadmium stress had small impact on the germination rate and germination index of maize seeds, but it had obvious effects on the vigor index, root and shoot growth of maize seeds, and the inhibition effects on the roots were more obvious than the shoots. Among the 12 varieties of maize, Qiandan 12, Dushiliren, Nuobatianxia and Nongda 3138 were tolerant to cadmium stress, while Tianguan 218 was sensitive to cadmium stress, and the tolerance of other varieties of maize to cadmium stress was moderate.展开更多
Tomato seedlings damping-off is a limiting factor in commercial greenhouse production. To determine the causal agents of disease, sampling and fungal isolation were performed during 2012. Samples were collected from i...Tomato seedlings damping-off is a limiting factor in commercial greenhouse production. To determine the causal agents of disease, sampling and fungal isolation were performed during 2012. Samples were collected from infected seedlings growing in greenhouses in the Syrian coastal region. Isolation of fungi was done in the laboratories of the Agronomical Reaserch Center, in Lattakia and the molecular analyses were done in the Biotechnology Center at Tishreen University, Lattakia, Syria, during the years 2012, 2013. Eight isolates ofPythium sp. obtained were purified using hyphal tip method （named P1, P2, P3, P4, P5, P6, P7 and P8）. Isolates were morphologically identified by optical microscope, then molecularly Characterized using genus specific ITS primers. The results of morphological characterization of pathogenic species suggested the detection of Pythium aphanidermatum, P. ultimum. The analysis of DNAs from the different isolates with ITS primers, recognizing the inter transcript spacer of nuclear ribosomal DNA proved that the eight, isolates were belonging to the species P. ultimum. The complete sequences of ribosomal DNA internal transcribed spacers regions of selected isolates were determined and submitted to GenBank. The GenBank-BLAST homology search revealed P. ultimum as the most similar sequence （〉 96% identity） with GenBank entry AB355596.展开更多
基金Supported by Key Laboratory of Pesticide Harmless Application of an University in Hunan Province
文摘To ascertain the genotypic difference of cadmium tolerance of different varieties of maize, effects of cadmium stress on the germination rate, germination index, vigor index, root length and fresh weight, and shoot length and fresh weight of seeds of 12 main varieties of maize widely cultivated in central Hunan were studied. The results showed that the cadmium stress had small impact on the germination rate and germination index of maize seeds, but it had obvious effects on the vigor index, root and shoot growth of maize seeds, and the inhibition effects on the roots were more obvious than the shoots. Among the 12 varieties of maize, Qiandan 12, Dushiliren, Nuobatianxia and Nongda 3138 were tolerant to cadmium stress, while Tianguan 218 was sensitive to cadmium stress, and the tolerance of other varieties of maize to cadmium stress was moderate.
文摘Tomato seedlings damping-off is a limiting factor in commercial greenhouse production. To determine the causal agents of disease, sampling and fungal isolation were performed during 2012. Samples were collected from infected seedlings growing in greenhouses in the Syrian coastal region. Isolation of fungi was done in the laboratories of the Agronomical Reaserch Center, in Lattakia and the molecular analyses were done in the Biotechnology Center at Tishreen University, Lattakia, Syria, during the years 2012, 2013. Eight isolates ofPythium sp. obtained were purified using hyphal tip method （named P1, P2, P3, P4, P5, P6, P7 and P8）. Isolates were morphologically identified by optical microscope, then molecularly Characterized using genus specific ITS primers. The results of morphological characterization of pathogenic species suggested the detection of Pythium aphanidermatum, P. ultimum. The analysis of DNAs from the different isolates with ITS primers, recognizing the inter transcript spacer of nuclear ribosomal DNA proved that the eight, isolates were belonging to the species P. ultimum. The complete sequences of ribosomal DNA internal transcribed spacers regions of selected isolates were determined and submitted to GenBank. The GenBank-BLAST homology search revealed P. ultimum as the most similar sequence （〉 96% identity） with GenBank entry AB355596.
