A new mutant indica rice diseases resistance variety 'Zhe101' by space mutation

Air-dried seeds of indica rice variety 'Zhe 9248' were carried by recoverable satellite, mutagenic effects of outer space environment of 175-354 km on indica rice was studied. Wider segregation spectrum of major characters, such as plant height, growth period duration (GPD), length of panicle, 1000-grain weight and so on, were found in the SP2 generation. A mutant variety 'Zhe101' selected from the space mutation progenies was improved significantly in GPD, disease resistance and yield. It was released in Oct. 2005 as an early indica rice in the double-cropped Yangtze River area. It has high, stable yield potential under normal fertilization. In Zhejiang Regional Trials in 2003-2004, it yielded 7189.5 kg/ha, 3.7% higher than the check' Jiayu293'. Blast resistance of 'Zhe 101' spared to be obvious superior to the parent and check. The average scale of leaf blast was only 0.8, the neck node blast was 1.5, causes a damage rate is only 2.6% on average. The average scale of bacterial leaf blight disease resistance was 4.0. The successful breeding of 'Zhe 101' showed that space mutation is an effective method to simultaneously improve multi-characteristics, and especially in diseases resistance improvement of rice. (authors)