籼稻花粉无性系变异的研究

对７个籼稻品种通过花药培养获得的１６１个花粉植株进行了花粉无性系变异的研究。结果表明：（１）所有花粉无性系在遗传上都是纯合的，其整齐度与起始亲本相近或超过起始亲本；（２）花粉无性系的变异主要在数量性状上有一定变幅，变异方向有负向也有正向的。同一来源的无性系间的变异系数略高于起始亲本，仅千粒重达到显著标准。以所考查的性状为基数，变异的频率为１２．５％，同时有３－４个性状发生变异的无性系数占总数的４．３％；（３）少数变异体性状有重大变异，并具有育种价值；（４）根据１０种同工酶和ＲＦＬＰ分析，仅从３个性状发生重大变化的变异体中检测出与起始亲本的差异。

Gametoclonal Variation of Microspore Derived Doubled Haploids in Indica Rice:Agronomic Performance,Isozymes and RFLP Analysis

A total of 161 doubled haploid(DH)lines produced by anther culture from 7 indica rice cultivars:Dayeda,Lizao 1,129,Erjiuqing,IR50,IR58 and Pelde were investigated for gametoclonal variations in agronomic performance,isozyme and RFLP analysis.Six agronomic traits:days to heading,plant height,productive tillers,grains per panicle,fertility and 1000 grain weight were assessed in H2 and H3,and only lines with significant quantitative alterations in above two generations were related to variants.The results indicated that all DH lines were uniform and genetic stable and the ranges of alterations were almost comparable with their initial parents.The variations were mainly on quantitative traits,showing either negative or positive effects.The variation frequency of traits was 12.5% based on total traits assessed.The variant lines with 3-4 altered traits were 4.3% in total lines investigateds. Several variants with distinctly improved agronomic traits were obtained.Of the 83 DH lines analysed with 10 isozymes and 25 RFLP markers covering all 12 chromosomes of rice, only 3 variants with remarkably altered traits from cultivar Erjiuqing showed variations at one esterase locus and one RFLP marker.