【摘要】 本文以云南松和烟草为材料，研究了钙对花粉萌发和花粉管生长的效应。结果表明花粉萌发介质中高浓度的钙（１０￣（－１）～１０￣（－１）２ｍｏｌ／Ｌ）显著抑制了云南松和烟草的花粉萌发和花粉管生长，而较低浓度的钙或缺钙（１０￣（－３）～０ｍｏｌ／Ｌ）对花粉萌发和花粉管生长无明显影响。测定萌发过程中花粉钙含量变化的结果表明，花粉水合阶段和萌发早期有一急剧的钙释放高峰。在培养介质中加入钙螫合剂ＥＧＴＡ抑制了花粉的萌发，但这种抑制可被随后加入的钙所逆转。钙通道阻塞剂Ｖｅｒａ－ｐａｍｉｌ和Ｃｏ￣（２＋）也能抑制或阻止花粉萌发，但这种抑制主要发生在花粉萌发的早期。此外，在同样浓度的钙载离子体Ａ＿（２３１８７）的处理下，花粉管生长比花粉萌发过程更为敏感。上述结果暗示着钙可能作为花粉萌发的启动者（Ｉｎｉｔｉａｔｏｒ）和花粉管生长的调节者（Ｒｅｇｕｌａｔｏｒ）来启动花粉萌发和调节花粉管生长。更多还原

【Abstract】 The initiating effects of Ca￣(2+)on pollen germination and its regulative role in pollen tube growth were investigated in Pinus yunnanensis and Nicotiana tabacum. High concentration of Ca￣(2-)(10￣(-1)～IO￣(-2)mol/L)in the medium caused severe inhibition of pollen germination and tube growth,but lower concentration of Ca￣(2+)or Ca￣(2+)-deficiency(10￣(-3～0mol/L)had little effect on pollen ger-mination and tube growth. Measurement of Ca content in germinating pollen showed that there was a significant Ca￣(+2) release from pollen during the hydration and early germination phase. How-ever,Ca￣(2+)specific chelating agent EGTA led to the inhibition of pollen germination,and this inhibi-tion could be eliminated by re-adding excess Ca￣(2+)to the medium containing EGTA. Ca￣(2+)channel blockers verapamil and Co￣(2+)also caused the inhibition or failure of pollen germination, In addition,Ca￣(2+)ionophore A23187 impeded pollen germination and tube growth. Unlike veraparmil and Co￣(2+)treatments,pollen tube growth was more sensitive to A23187 than pollen germination. These results suggested that Ca￣(2+)is indispensible for pollen germination and tube growth although exogenous addition of Ca￣(2+)to the medium is not necessary. The uptake of Ca￣(2+)occurred mainly in early germi-nation phase, and Ca￣(2+)could act as an initiator of pollen germination and also as a regulator of pollen tube growth.更多还原