大花蕙兰与国兰花粉活力及柱头可授性分析

Pollen vitality and stigma receptivity of Cymbidium hybridum and Chinese orchid

花粉和柱头具有较高的活力是保证杂交育种工作有效开展的关键。采用氯化三苯基四氮唑（TTC），碘，碘化钾（I2-KI）和醋酸洋红等3种染色法测定了大花蕙兰Cymbidium hybridum和国兰不同种和品种的花粉活力，用联苯胺-过氧化氢法测定了大花蕙兰和国兰部分品种的柱头可授性并观察柱头分泌黏液情况。研究结果表明：碘一碘化钾染色法和醋酸洋红染色法都不适合大花蕙兰和国兰花粉活性的测定，TTC染色法是观察花粉活力最直观的方法。大花蕙兰与国兰的花粉活力是随着开放时间的延长，经历从弱变强再变弱的过程，大花蕙兰和国兰的花粉分别在开后25～35d和15～25d活力最佳。大花蕙兰和国兰的柱头在整个花期中均具有一定的可授性，其中大花蕙兰在20～40d内的可授性最强，45d以后其柱头可授性逐渐减弱。国兰在15～25d内的柱头可授性最强，30d以后柱头的可授性逐渐消失。总体而言，整个柱头可授性是随着时间的变化从弱到强再到弱的一个过程。

To ensure effective cross-breeding work, high vitality of pollen and stigma receptivity are required. 2, 3, 5-triphenyhetrazolium chloride（TFC）, iodine-potassium iodide（I2-KI）, and Carmine staining methods were used to determine pollen viability for Cymbidium hybridum and Chinese orchid; benzidine-H202 was utilized to determine stigma receptivity and to observe stigma mucus secretion. Results indicated that the I2-KI and Carmine methods were not suited to test pollen vitality while the TTC method verified to be best. Throughout flowering, the stigmas of Cymbidium hybridum and Chinese orchid were receptive. The stigma of Cymbidium hybridum reached its highest receptivity from 20 d to 40 d, after flowering, stigma receptivity gradually weakened after 45 d. For the Chinese orchid from about 15 d to 25 d, receptivity strengthened, but at 30 d, stigma receptivity gradually weakened and disappeared. Thus, the stigma receptivity process changed from weak to strong to weak.