Preliminary Study On Distant Hybridization Between Acer Buergerianum Miq And Acer Paxii Franch

Acer buergerianum Miq is one of the excellent local trees.It is famous for its powerful budding force, strong cold resistance. Acer paxii Franch is evergreen tree and distributed mainly in the Jinsha River basin.There are very few new varieties of cold resistant evergreen trees; Therefore, it is very importance to make use of advantages of the two trees and break the hybridization barriers of them.This article include the following researchs: First, the flowering phenology of Acer buergerianum Miq and Acer paxii Franch were observed to determine the time range of pollen collection. Second, Taking Acer buergerianum Miq and Acer paxii Franch pollen as experimental materials, through the single factor of sucrose, boric acid and the calcium chloride and 3 factors orthogonal experiment conditions on pollen germination discussed the role of PEG4000 on pollen germination. While studied the best optimal culture time of the pollen germination. spare pollen were placed at 25℃、4 ℃、-20 ℃、-80 ℃ and find out the suitable storage condition. Third, the barriers of the hybridization between Acer buergerianum Miq and Acer paxii Franch were dicovered and the solution for the problem was tried to raise. Fourth, Taking Acer paxii Franch Seeding as the experimental material, we should measure the seedling height and ground diameter growth,then pointed out each growth stage. To improve the quality of seedlings, different nursery methods could be applied in different periods. The results are as follows:(1) The florescence of Acer buergerianum Miq is from late March to mid April, the flowering period is 20 ~ 26 d, single flower period is generally 3 ~ 6d. The florescence of Acer paxii Franch is from the beginning to the late of April, the flowering period is 21 ~ 28 d, single flower period is generally 3 ~ 6d. The blossom time of male flowers is earlier than the hermaphrodite flowers.(2) The optimal culture solution of Acer buergerianum Miq is sucrose 100g/L + H3BO3200mg/L + CaCl230mg/L; The optimal culture solution of Acer paxii Franch is sucrose 150g/L + H3BO3150mg/L + CaCl250mg/L. The proper culture time of Acer buergerianum Miq pollen were 24 h and the proper culture time of Acer paxii Franch pollen for observation were 21 h. The pollen of Acer buergerianum Miq and Acer paxii Franch can keep vitality for more than one year under-80℃.(3) The fluorescence microscopy observation showed that the pollens of Acer paxii Franch can germinate on the stigma of Acer buergerianum Miq, but fail to enter into the style,that was the so-called prefertilization barriers. At the same time,there are few pollens of Acer buergerianum Miq on the stigma of Acer paxii Franch.So six sulotions were tried, they were stigma-cutting, the use of medium of male parent pollen, and GA solution smearation. useusing delayed pollination,a small amount of pollen tube can reach ovary. It must be tried more in the coming studies.(4) The time of Acer paxii Franch seed germination is about 5~20d and the growth period is about 230 d with height 47.35 cm, diameter of 0.48 cm. Seedling emergence is later than the high growth. The growth characteristics of diameter and height is similar.First, the initial growth was slow, after a period of time the growth enter to the high-speed period, then,followed by a slow growth period.