Creating a crop-heterogeneous system by intraspecific mixtures of different rice varieties can substantially reduce blast diseases. Such variety mixtures provide an ecological approach for effective disease control, m...Creating a crop-heterogeneous system by intraspecific mixtures of different rice varieties can substantially reduce blast diseases. Such variety mixtures provide an ecological approach for effective disease control, maintaining high yields with the minimum fungicide applications. Whether such an approach is universally applicable for random rice variety combinations and what is the variation pattern of the diseases under intercropping still remains unclear. We conducted two-year large-scale field experiments involving 47 rice varieties/lines and 98 variety-combinations to compare the occurrence of rice blast in monoculture and intercropping plots at multiple sites. In the experiments, the plant height of the selected tradi- tional varieties was about 30 cm taller, and their life cycle was 10 days longer, than that of the improved rice varieties. The monoculture included either traditional or modern rice varieties grown in separate plots. The intercropping included both traditional and modern rice varieties planted together in the same plots. Results from the field experiments under natural disease conditions demonstrated significant reduction for rice blast disease in intercropping plots, compared with that in monoculture plots. For traditional varieties, the average blast incidence reduced from -26% in monoculture to -10% in intercropping, and the disease severity reduced from -17 in monoculture to -5 in intercropping. For modern varieties, the average blast incidence reduced from -19% in monoculture to -10% in intercropping, and the severity from -10 in mono- culture to -4 in intercropping. Traditional rice varieties （-72%） had a much greater increase in the efficiency of disease control than modern varieties （-60%）. In addition, substantially lower values of variance in the blast incidence and severity was detected among the variety combinations in intercropping plots than in monoculture plots. Based on these results, we conclude that the intercropping or mixture of rice varieties greatly reduces the occurrence and variation of rice blast disease in particular variety combinations, which makes the intercropping system more stable and consistent for disease suppression on a large scale of rice cultivation.展开更多
Computer based software such as the SignalP v3.0, TargetP v1.01, big-PI predictor and TMHMM v2.0 were combined to predict the signal peptides, and the signal peptide-dependent secreted proteins among the 6 700 ORFs in...Computer based software such as the SignalP v3.0, TargetP v1.01, big-PI predictor and TMHMM v2.0 were combined to predict the signal peptides, and the signal peptide-dependent secreted proteins among the 6 700 ORFs in genome of Saccharomyces cerevisiae. The results showed that 163 proteins were the secreted ones containing signal peptides, and they were secreted via Sec pathway. Among the 163 predicted secreted proteins, the signal peptides of 47 secreted proteins included only the H-domain and C-domain, without N-domain, but the signal peptides of other 116 secreted proteins included all the three domains. There were differences in the constitution of signal peptides between the secreted proteins of S. cerevisiae and of Candida albicans, but the length and amino acids types of their signal peptides were similar in general. Few of the same signal peptides occurred in the secreted proteins of S. cerevisiae genome, and the homology could be compared among the secreted proteins with the same signal peptides. The BLAST 2 SEQUENECES and CLUSTAL W were used to align the two protein sequences and multi-protein sequences, respectively. The alignment result indicated that homology of these sequences with the same signal peptide was very highly conservative in amino acid of complete gene. The effect of the signal peptides in S. cerevisia on expression of foreign eukaryotic secreted proteins is discussed in this paper.展开更多
基金funded by the National Basic Research Program of China (2011CB100401)
文摘Creating a crop-heterogeneous system by intraspecific mixtures of different rice varieties can substantially reduce blast diseases. Such variety mixtures provide an ecological approach for effective disease control, maintaining high yields with the minimum fungicide applications. Whether such an approach is universally applicable for random rice variety combinations and what is the variation pattern of the diseases under intercropping still remains unclear. We conducted two-year large-scale field experiments involving 47 rice varieties/lines and 98 variety-combinations to compare the occurrence of rice blast in monoculture and intercropping plots at multiple sites. In the experiments, the plant height of the selected tradi- tional varieties was about 30 cm taller, and their life cycle was 10 days longer, than that of the improved rice varieties. The monoculture included either traditional or modern rice varieties grown in separate plots. The intercropping included both traditional and modern rice varieties planted together in the same plots. Results from the field experiments under natural disease conditions demonstrated significant reduction for rice blast disease in intercropping plots, compared with that in monoculture plots. For traditional varieties, the average blast incidence reduced from -26% in monoculture to -10% in intercropping, and the disease severity reduced from -17 in monoculture to -5 in intercropping. For modern varieties, the average blast incidence reduced from -19% in monoculture to -10% in intercropping, and the severity from -10 in mono- culture to -4 in intercropping. Traditional rice varieties （-72%） had a much greater increase in the efficiency of disease control than modern varieties （-60%）. In addition, substantially lower values of variance in the blast incidence and severity was detected among the variety combinations in intercropping plots than in monoculture plots. Based on these results, we conclude that the intercropping or mixture of rice varieties greatly reduces the occurrence and variation of rice blast disease in particular variety combinations, which makes the intercropping system more stable and consistent for disease suppression on a large scale of rice cultivation.
基金This work is supported by the National Natural Science Foundation of China （30360061）Natural Science Foundation of Yunnan Province of China （1999C0008Z） National 863 Program of China （2003AA211020）.
文摘Computer based software such as the SignalP v3.0, TargetP v1.01, big-PI predictor and TMHMM v2.0 were combined to predict the signal peptides, and the signal peptide-dependent secreted proteins among the 6 700 ORFs in genome of Saccharomyces cerevisiae. The results showed that 163 proteins were the secreted ones containing signal peptides, and they were secreted via Sec pathway. Among the 163 predicted secreted proteins, the signal peptides of 47 secreted proteins included only the H-domain and C-domain, without N-domain, but the signal peptides of other 116 secreted proteins included all the three domains. There were differences in the constitution of signal peptides between the secreted proteins of S. cerevisiae and of Candida albicans, but the length and amino acids types of their signal peptides were similar in general. Few of the same signal peptides occurred in the secreted proteins of S. cerevisiae genome, and the homology could be compared among the secreted proteins with the same signal peptides. The BLAST 2 SEQUENECES and CLUSTAL W were used to align the two protein sequences and multi-protein sequences, respectively. The alignment result indicated that homology of these sequences with the same signal peptide was very highly conservative in amino acid of complete gene. The effect of the signal peptides in S. cerevisia on expression of foreign eukaryotic secreted proteins is discussed in this paper.
