辐照花粉对普通小麦×窄颖赖草杂种的细胞学效应

CYTOLOGICAL EFFECTS OF POLLEN IRRADIATION ON WHEAT× Leymus angustus Hybrids

以普通小麦J11( Triticu m aestivu m ) ×窄颖赖草( Ley m us angustus)( 花粉经9Gy γ射线辐照,以不辐照的为对照) 杂种幼胚愈伤组织及其再生植株为材料,研究了辐照花粉对其远缘杂种的细胞学效应。结果表明,辐照花粉对其杂种表现出以下细胞学效应:①明显增加了杂种愈伤组织的染色体数目变异幅度,对照为43 ～64 条,而9Gy 辐照的为26 ～65 条;②使杂种愈伤组织染色体数目减少,平均每细胞减少4-9 条染色体;③促进了杂种染色体结构变异,对照染色体结构变异主要为端着丝粒染色体,而辐照的除具有与其相近频率的端着丝粒染色体外,还有与其相近频率的微小染色体;④增加了双着点染色体和环状染色体等的频率,表明辐照花粉促进了染色体易位和重组。

Cytological effects of pollen irradiation on wheat× Leymus angustus hybrids were studied using callus clones and their derived plants of hybrid embryos as experimental materials. The results showed that variation range of chromosome number (VRCN) of hybrid callus clone became wider afte pollination with irradiated paternal pollen. VRCN of the control clone was 43～64, and 26～66 was found in 9Gy treatment clone. The average chromosome number per cell decreased by 4 9. Pollen irradiation enhanced chromosomal structural aberration(CSA). The CSA frequency was 45 35% in the control clone, and 77 31% in 9Gy treatment clone. The main CSA in the control clone was telocentric chromosome. Except for telocentric chromosomes, there were also minichromosomes in 9Gy treatment clone with the similar frequency to telocentric chromosomes. The higher frequency of dicentric and ring chromosomes and fragments in 9Gy treatment showed that pollen irradiation enhanced chromosomal translocation and recombination.