偏凸-柱穗山羊草双二倍体与普通小麦杂种F_1的细胞遗传学分析

Cytogenetic Analysis of Hybrid F_1 of Common Wheat and Aegilops Ventricosa × Aegilops Cylindrica Amphidiploid

[目的]研究偏凸-柱穗山羊草双二倍体与普通小麦杂种F1的染色体配对特点。[方法]利用压片法对普通小麦烟农15、SDAU18及其杂种F1的小孢子发生和花粉发育过程进行了细胞学观察。[结果]两亲本(烟农15和SDAU18)的小孢子发生和花粉发育基本正常,二者结实率也基本正常。F1小孢子发生过程紊乱,花粉母细胞减数分裂中期I出现较高频率的单价体和二价体,分别为10.11和18.29个,而多价体出现的频率非常低;减数分裂后期I,每个细胞落后染色体平均为5条;四分体期,每个四分体微核数平均为4.43个。在杂种F1花粉发育的每个时期都产生了不同频率的败育花粉,但败育主要发生在第1次孢子有丝分裂以后。在三细胞成熟花粉期,杂种F1可育花粉仅有31%。[结论]为深入分析和利用该双二倍体提供了细胞遗传学依据。

[objective] The aim of this study is to investigate the chromosome pairing of F1 from Aegilops ventricosa-Aegilops cylindrica amphiploid × common wheat.[Method] Microsporogenesis and pollen development of Yannong15,SDAU18 and their hybrid F1 were observed cytologically by squash method.[Result] The results showed that microsporogenesis and pollen development of two parents including Yannong15 and SDAU18 were basically normal,and their seed setting rate was also basically normal.However,the microsporogenesis of their hybrid F1 was chaotic.Univalent and bivalent with high frequency of 10.11 and 18.29 per cell respectively occurred in meiotic MⅠ（metphaseⅠ） of PMC（pollen mother cell）.Nevertheless,only quite low frequency of multivalents occurred in meiotic PMC MⅠ.The laggards at meiotic AI（anaphaseⅠ） were 5 per cell on average.The number of micronucleoli in tetrad was 4.43 per cell averagely.The aborted pollen with different frequency occurred at every stage of hybrid F1 pollen development but mainly after single nucleus pollen stage.The fertile pollen rate of hybrid F1 was only 31% at 3-nucleated stage.[Conclusion] This study provides cytogenetics basis for further analysis and utilization of the amphiploid.