九个水稻耐盐突变体的RFLP分析

RFLP ANALYSIS OF NINE SALT TOLERANT RICE MUTANTS

用６ 个可能与水稻耐盐性有关的ＤＮＡ 探针对来自两个品系的５ 个耐盐突变株系、３ 个耐盐突变体及１ 个弱耐盐突变体进行ＲＦＬＰ分析。结果有８ 个耐盐突变体（株系）检测到ＤＮＡ 水平的变化，６ 个探针检测到具多态性的突变株系（体）的数目分别为ＲＧ４：６ 个；ＲＧ７１１：６ 个；Ｒａｂ１６：５ 个；Ｒａｂ１０Ｅ６：２ 个；Ｒａｂ２１：１ 个；ＳａｌＴ：２ 个；表明ＲＧ４、ＲＧ７１１ 及Ｒａｂ１６三个位点有可能与耐盐性突变相关。多态性图谱中７０．８％ 为２ 个以上的酶切图谱同时显示多态性，说明多数突变是由缺失。

The NaCl tolerant calli of “77 170” were selected from 1800 anthers, treated with ethylmethanesulphonate (EMS) or untreated, on N 6 agar medium containing 0 5%, 0 8%, and 1 0% NaCl respectively.Twenty two seed setting plants were obtained from R 1 pollen plants among the NaCl tolerant green plantlets.Through selection in soil cotaining 0 5% NaCl for 10 successive generations, five NaCl tolerant lines named as mutant 15,16,17,19,20 were obtained at length.In the soil containing 0 5% NaCl, tolerant R 10 plants of those five selected lines were much better than the control in growth and yield.Other NaCl tolerant lines named as mutant P 2,R 2,R 3,YCR were selected from young inflorescence of “98”and “77 170” (P 2 only).The procedure of selection and regeneration was nearly the same as the above mentioned. As the six probes used, three of them (Rab16,21,10E6) were specific cDNA clones isolated from rice callus, which transcription was induced by ABA or salt treatment, other two probes (RG4, RG711) were discovered in our laboratory and located on chromosome 7, and salT was a specific cDNA clone which only expressed in roots and sheaths under salt treatment. The RFLP survey showed that eight tolerant mutants were different from their respective controls at the six detectable chromosome loci.The number of mutants showing polymorphism for different probes was as follows,6 for RG4, 6 for RG711, 5 for Rab16, 2 for Rab10E6, 2 for salT and 1 for Rab21 respectively. This result suggested that the loci RG4, RG711 and Rab16 might be correlated with salt tolerance in rice. The weak salt tolerant one did not show any polymorphism with control by using six DNA probes.70.8%(17/24) of all polymorphic autoradiograms showed polymorphism on patterns which were obtained by digestion of at least two restriction enzymes. It seemed that the majority of mutations were caused by insertions or deletions. Comparing the RFLP results of R 3 resistant callus and single regenerative R 3 stalk, the existance of mosaic in R 3 resistant callus was obviously observed.This suggested that protoplast screening before regeneration is an efficient way to obtain stable resistant line.When Rab16 was used as probe, the autoradiogram was complicated by the appearance of many weak bands which indicated that Rab16 could be a gene family.