Research on Mutation in Rice (Oryza Sativa L.) Induced by High Hydrostatic Pressure

Seeds of three rice (Oryza sativa L.) cultivars, Yuexiangzhan, Yuefengzhan and Ce 64, were soaked for 10 h, and then were treated by high hydrostatic pressure (78 MPa) for 12 h. The seedlings of high-pressure treatment and control were transplanted in the field after sowing of 30 d. Mutation type of characters and selection of excellent varieties were investigated. The results indicated that: (1) In M1 generation, grain numbers per panicle of Yuexiangzhan, Yuefengzhan and Ce 64 treated by high hydrostatic pressure (HHP) increased by 5.2%, 1.2% and 17.0%, respectively. Ce 64 delayed 10 d but Yuexiangzhan and Yuefengzhan advanced 5 d and 2 d in period of duration. (2) There were quality and quantity traits among the mutation traits by HHP. For instance, dominant mutation in leaf sheath made green leaf sheath become purple leaf sheath, while recessive mutation in the node length below panicle made node length of treatment longer than that of control. Mutation in plant height, awn length and grain numbers per panicle belonged to mutation of quantity traits. (3) Mutation frequency and the time from mutant to stable mutation lines varied among species. Mutation frequency of Ce 64 in M1 generation was 8% while that of Yuefengzhan and Yuexiangzhan was 1 and 5, respectively. (4) Currently one hundred mutants were found in the field. Twenty two mutants had no significant separations and seven of them displayed remarkable advantages in comprehensive traits than their control.