【摘要】 试验选用孤雌生殖单倍体诱导率存在差异的不同类型自交系为材料 ,利用 DAPI荧光染色方法对离体萌发花粉管中两个精核之间的距离进行了观察统计。结果显示 ,具有 2个精核、1个精核和无精核花粉管的百分率与单倍体诱导率均不存在相关关系。在具有 2个精核的花粉管中 ,根据不同精核间距分布组之间的相互关系推测 ,存在着 2个相互独立的花粉管亚群 ,即精核间距小于花粉管平均直径的密亚群和大于花粉管平均直径的疏亚群。其中 ,密亚群花粉管的分布频率与单倍体诱导率无关 ,而疏亚群中精核间距小于花粉粒平均半径组的分布频率与单倍体诱导率呈显著的负相关 ,精核间距大于花粉粒平均半径组的分布频率与单倍体诱导率之间则表现极显著的正相关 (r=0 .896)。因此 ,相当于花粉粒平均半径长度的精核间距是区分花粉管是否具有诱导单倍体作用的分水岭。更多还原

【Abstract】 Based on materials with different potential for haploid inducing,the distance between two sperm nuclei of pollen tubes germinating in vitro was observed and analyzed by dying the nuclei of various maize inbred lines with fluorescent agent DAPI.The results indicated that there were no relationships between the distributive frequencies of pollen tubes with double nuclei,single nucleus or zero nucleus and the percentage of haploid induced (PHI) by the same source pollen.The findings also showed that there existed two independent sub populations,the tight subpopulation with inter sperm nuclei distance (ISND) shorter than the average diameter of pollen tube and the loose one longer than the diameter,among different groups of double nuclei pollen tube according to their correlation coefficients.In tight sub population,the distributive frequencies of pollen tube groups were unrelated with PHI.And in loose sub population,the frequencies of pollen tube group with ISND shorter than mean pollen radius had significantly negative correlation with PHI,while those with ISND longer than mean pollen redius correlated positively and significantly with PHI ( r =\{0.896\}).As a result,the approximate value of ISND equivalent to mean pollen radius was the threshold to discriminate pollen tubes potential for haploid inducing.更多还原