Studies On The Rice Bentazon Sensitive Lethality Mutant Induced By γ-ray Radiation

At present,the planting area of hybrid rice has reached 15 million hectare,as much as half of the total rice area and its yield take 58%of that of paddy,which takes important role in our nation's food security.Now the process of the hybrid seed production mainly relies on manual,the working procedure is very burdensome.As a chemical selection mark,rice bentazon sensitive lethality(bel)gene is controlled by recessive gene.If the bel gene is transferred into restoring line,the parents of hybrid rice can be planted mixedly and harvested by machine,which will improve out-crossing rate and mechanization.We usedγ-ray to radiate japonica restorer line C418 and indica restorer line Zhehui 7954 to create the mutant with bentazon sensitive lethality.The result is as followed:1.Both japonica restorer line C418 and indica restorer line Zhehui 7954 were treated with 350Gy ⁶⁰Coγ-ray irradiation.M₀ was planted in the Shucheng basement.We planted 12000 (6000 from each variety)M₁ seeds in the green house,and daubed by bentazon of 400mg/L in the three-leaf period.Finally we have obtained bentazon sensitive lethal mutant of restoring line 7 individuals,of which 4 from C418,and 3 from Zhehui 7954.2.According to the comparison bel gene sequence between DQ341412 for indica rice and NT₁07187 for japonica rice,we designed 4 primers:Ben001,Ben002,Ben003,Ben004, and gave polymerase chain reaction(PCR)test to the mutants with these primers.We found that primer Ben 002 did not amplify band in the mutant C418m279,and primer Ben 004 did not amplify band in the mutant C418m105.Other primers amplified clear bands and the size are accord with the intending size.3.We moved the filtered bel mutants into paddy in season,and tested the photosynthesis and chlorophyll fluorescence data before and after treatment with bentazon of 400mg/L.the analysis to the data of photosynthesis and chlorophyll fluorescence realized that the difference of photosynthesis indexes between the bel mutants and their wild types is obvious.