A Study on Pollen Viability of Piper colubrinum Link

Pollen viability study on Piper colubrinum Link. carried out to develop interspecific hybridization between P. nigrum L. and P. colubrinum Link.. This plant has good potential as a donor plant in breeding programme for Phytophthora to foot rot resistance in the cultivated species, P. nigrum. This project was carried out to reveal the optimum time to collect pollen of P. colubrinum for artificial pollination. Through this study, anther dehiscence was proved occurred around 9 am. Based on the result obtained from study on the time of anther dehiscence, the pollen was classified into five stages for testing on the viability, i.e., stage 1, before anther dehiscence, i.e., around 7 am （pollen obtained by crushing on the anther）; stage 2： immediately after anther dehiscence, i.e., around 9 am; stage 3： two hours after anther dehiscence, i.e., around 11 am; stage 4： four hours after anther dehiscence, i.e., around 1 pm; and stage 5： six hours after anther dehiscence, i.e., around 3 pm. Data obtained from pollen germination and pollen tube growth study showed that pollen of P. colubrinum was the most viable at two hours after anther dehiscence and onward. It was also proved that the viability can be maintained up to at least eight hours. Pollen obtained before anther dehiscence by crushing on the anther was found less viable with lower percentage of pollen germination and retarded pollen tube growth. In other words, the experiment enlightened that artificial pollination between P. nigrum L. and P. colubrinum Link was ideally to be carded out approximately starting from 11 am until 5 pm, considering the viability of pollen ofP. colubrinum.

Pollen Germination in vitro and Pollen Storage of the Eggplant(Solanummelongena L.)

The eggplant (Solanummelongena L.) is widely cultivated across the world.Technology regarding the in vitro germination and preservation of eggplant pollen is important for the production of hybrid seeds.In this work,the suitable cultural medium and time for the germination of fresh and dried pollen was investigated.The results showed that a suitable medium for eggplant pollen germination was 0.5% agar+5% sucrose+0.01% boric acid+0.01% GA3,the suitable culture time was 2 h for fresh pollen and 4 h for dried pollen stored at low temperature.GA3 could induce the germination of dried and stored pollen. The better way to dry anthers was 4 h in a desiccator at 25~30℃.We also found that pollen from the second to the fourth branch has the highest germination rate. Furthermore,there were no significant differences in the seed setting rates among the different storage temperatures and storage times,whereas the number of viable seeds formed per fruit differed significantly,which was 87.3% more for pollen stored at -80℃ and fresh pollen than that stored at 4℃.This work optimized pollen storage conditions and is helpful to eggplant hybrid seed production.

Artificial Pollination and Seed Germination of Dendrobium candidum Wall. ex Lindl.

The artificial pollination and the seed germination on Dendrobium candidum were conducted. Results showed that the percentage of fruit-setting reaches the highest under cross pollination before 10 o＇ clock in the morning after blooming 2 d to 4 d. The optimal medium for seeds germination was MS＋ NAA 0.5 mg/L ＋ potato juice 10% ＋ active charcoal 0.5%, and cultured for 7 d in the dark then under light.

芍药繁殖器官形态特征观察研究

石蜡切片观察显示,芍药花芽是混合芽,其发育成熟后是多种原基的复合体,由顶端生长点、叶原基、苞片原基、花萼原基、花瓣原基、雌雄蕊原基及芽鳞和叶原基腋内的腋芽原基组成。对花、果实、种子等繁殖器官的体视镜观察表明,芍药具有原始被子植物的形态特征,如雄蕊呈螺旋状排列、离心发育,有假种皮、果等。授粉萌发过程的荧光扫描电镜观察,授粉0.5小时后落置于柱头上的花粉粒已开始萌发,授粉1小时后花粉管生长迅速并全部穿过柱头进入花柱,花粉管在2～3小时内便进入胚珠。