Lesion-based analysis of leaf blast suppression in mixture of rice cultivar and a resistant near-isogenic line     

Taketo Ashizawa  Masashi Sasahara  Atsushi Ohba  Takeshi Hori  Kouji Ishikawa  Yukio Sasaki  Tomohisa Kuroda  Ryoei Harasawa  Kaoru Zenbayashi-Sawata  Shinzo Koizumi 《Journal of General Plant Pathology》2007,73(1):15-21

Leaf blast suppression in multilines was evaluated based on the number of susceptible lesions observed in a pure stand of susceptible rice cultivar Sasanishiki, and in 1 : 1 and 1 : 3 mixtures of Sasanishiki and a resistant near-isogenic line, Sasanishiki BL4 or BL7, from 1998 to 2001. The number of lesions first observed in fields in the 1 : 1 and 1 : 3 mixtures were close to theoretical numbers calculated using the number of lesions observed in the pure stands and the ratios of the susceptible Sasanishiki in the mixtures. The ratio of the number of lesions in the 1 : 1 and 1 : 3 mixtures to the number in the pure stand was 0.29 and 0.09, respectively. The relationship between these ratios and the ratios of susceptible Sasanishiki in mixtures was defined in an equation to estimate the degree of leaf blast suppression. Validation studies for the ratios of the number of lesions in the 1 : 1 and 1 : 3 mixtures to the number in the pure stand were conducted in two different locations and showed that the ratios are almost acceptable. The calculated autoinfection to alloinfection ratio was 1.3 and 1.4 in the 1 : 1 and 1 : 3 mixtures, respectively, suggesting that the calculated ratio will affect the degree of leaf blast suppression. Thus, predictors were obtained to estimate leaf blast suppression for effective blast control in multilines.  相似文献   

Development of a measurement method for abrasion irrigation channel using underwater ultrasonic wave     

Nagaoka  Seiya  Okajima  Kenji  Ito  Ryoei  Watanabe  Ken  Islam  Mohammad Raihanul 《Paddy and Water Environment》2019,17(3):549-554

Paddy and Water Environment - Japan has many concrete irrigation channels with total length of about 400,000 km. Most of these channels are now too old for continued use. It would be too...  相似文献   

Chemical Characterization of Acid Fog and Rain in Northern Japan Using Back Trajectory and Oblique Rotational Factor Analysis     

Tetsuya Adzuhata  Tomoko Okamura  Junko Inotsume  Ryoei Kikuchi  Toru Ozeki  Masahiro Kajikawa  Nobuaki Ogawa 《Water, air, and soil pollution》2001,130(1-4):337-342

Fog/cloud and rain water were collected at the mountainside of Hachimantai range in northern Japan and rain water was also collected at Akita City in order to investigate the air pollutant scavenging mechanism. The concentrations of various ions in these samples were analyzed, and the fog drop size and the wind direction were measured at each fog event. The fog at Hachimantai range had a very high total ion concentration, and was considerably acidified by non sea salt (nss-) SO₄ ^2? and NO₃ ^?, compared with the rain at Akita and all sites in Hachimantai range. Using the oblique rotational factor analysis, three factors were extracted as the air pollutants; A: (NH₄)₂SO₄+H₂SO₄, B: sea salts+HNO₃+H₂SO₄, C: NH₄NO₃+OH^?. These salts are well-known as the cloud condensation nuclei (CCN). Combining the factor analysis with the 72h back trajectory at 850hPa level, the contribution of Factor A was closely connected to the long-range transportation of anthropogenic or natural aerosol in air masses of continental origin.  相似文献