用于筛选直链淀粉含量为中等的籼稻品种的分子标记

Development of a Molecular Marker for Screening the Rice Cultivars with Intermediate Amylose Content in Oryza sativa subsp. indica

用PCR AccⅠ分子标记检测方法 ,检测了来自不同地区的 6 3个栽培水稻品种 (系 )蜡质基因第 1内含子剪接供体 +1位碱基是G或是T。另外 ,还测定了这些水稻成熟种子的直链淀粉含量。结果显示该位置是G碱基的水稻品系成熟种子中直链淀粉含量均高于 2 0 % ,该位置是T的均低于 18%。在杂交育种过程中 ,这一分子标记可用于预测水稻植株种子的直链淀粉含量。对高直链淀粉含量的水稻亲本与中等直链淀粉含量的水稻亲本之间 5个籼型杂交组合F2 群体的分析表明 ,蜡质基因第 1内含子 +1位碱基是G或是T与水稻种子中直链淀粉含量的高或低是紧密连锁 ,共同分离的。这些结果表明PCR

A PCR Acc Ⅰ molecular marker has been developed and used to determine whether the first nucleotide of splice donor site of waxy intron 1 is G or T in 63 rice cultivars collected from different areas. In addition, the amylose content in mature seeds of these cultivars was determined (Table 1). The results show that the amylose content in the cultivars with base G at position +1 of waxy intron 1 is always above 20%, while that in all of the cultivars with base T at the corresponding position is below 18%. Thus, this PCR Acc Ⅰ molecular marker can be used to screen combinations for lower amylose content of grains and therefore better eating qualities. Analysis of the F 2 generations derived from five crosses between indica rice cultivers with high and intermediate amylose level shows that whether the first nucleotide is G or T in waxy intron 1 is related to high or low amylose content, respectively, in mature seeds, and they are co segragated (Table 2). Therefore, the PCR Acc Ⅰ molecular marker (Figs.1,2) can be used for the breeding of indica cultivars with intermediate amylose content.