Studies On The Reproductive Biology Of Elaeagnus Spp.

Using two introducted Elaeagnus spp. in Tianjin as materials, biological characteristics, phenophase, flower bud morphological differentiation, pollen culture in vitro, propagation characterristics, karyotype analysis, waterlogging physiological etc. were discussed in this study.1. Leaves, flowers, fruits and other biological characteristis of two Elaeagnus spp. were compared. The results showed: The two Elaeagnus spp. leaves are densely covered with scales, and the two are different in leaves, flowers, fruits and seeds.2. The phenophase of two Elaeagnus spp. and the relationship between tempreture and phenophase were studied. There were six phonological stages in Tianjin. Germination stage of E. moorcroftii was from 3/7～3/11,E. oxycarpa was one or two days earlier. Leaf-expansion stage of of E. moorcroftii and E. oxycarpa was respectivly from 3/30～4/2 and 3/28～4/2. On the second 10 days of April, the tree began to appear flower bud. In the biggining of May the two species began to flower, the florescence of two Elaeagnus spp. was uniform, and the florescence lasted 15 days. On the last 10 days of May bigan to apprear young fruit, and the fruits matured on the last 10 days of August. E. oxycarpa was five days earlier than E. moorcroftii. The dormancy stage was at the end of November, and E. oxycarpa was five or seven days later than E. moorcroftii.3. The anatomical characteristics of two Elaeagnus spp. flower bud during the process of differentiation by paraffin method were studied. The results showed that the differentiation proceses of two species were the same. The whole differentiation process may be divided into six stages, including flower bud undifferentiation stage, initial differentiation stage, bud differentiation stage, sepal differentiation stage, stamen differentiation stage and pistilstamen differentiation stage. The whole process was long, and it lasted 140 days.4. Pollens of Elaeagnus spp.were tested to study the effects of sucrose concentration (A), agar concentration(B), temperature(C) and boric acid concentration(D) on pollen germination by using the orthogonal design. The results showed that the order of affecting pollen germination was sucrose > boric acid > agar >tempreture. The optimum condition for pollen of Elaeagnus spp. germination was 20% sucrose , 0.5% agar, 25℃, 10% boric acid.5. Effect of different treatments on two Elaeagnus spp. was studied. The results indicated that the seed germination percentage, seed germination potential and seed germination index of two Elaeagnus spp. among different treatments reached a significant level. The seed germination percentage, seed germination potential and seed germination index of seed nucleus scarification of two Elaeagnus spp. were highest of all treatments. The treatments of seed nucleus scarification, 40℃, 60℃, GA3100mg/L, 98%H2SO4 3min and 98%H2SO4 5min could improve seed germination percentage of two Elaeagnus spp.. All treatments except 98%H2SO4 10min, 80℃and GA3 200 mg/L could improve seed germination potential of E.oxycarpa, and all treatments could improve its'seed germination index. All treatments except 98%H2SO4 10min, GA3 150 mg/L, GA3 200 mg/L and 80℃could improve seed germination potential of E. mooricroftill, and all treatments except 98%H2SO4 10min, GA3 200 mg/L and 80℃could improve its'seed germination index.6. The cuttage experiment indicated that the effect on the Elaeagnus spp. cuttage survival rate of different treatments was very big. The cuttage survival rate of IBA 100 mg/L processing was the highest, and it was obviously higher than that of NAA 100 mg/L, and it was very significantly higher than other processing, enhanced 84.84% compared to the control. The second highest was NAA 100 mg/L , its'survival rate was no significant difference with IBA 50 mg/L , and it was obviously higher than GA3 100 mg/L, IBA 150 mg/L, NAA 50 mg/L and GA3 50 mg/L, very significantly higher than NAA 150 mg/L, CK, IBA 200 mg/L, NAA 150 mg/L, GA3 200 mg/L, GA3 200 mg/L, enhanced 52.27% compared to the control。7. The karyotype analysis was carried out on Elaeagnus moorcroftii and Elaeagnus oxycarpa using root tips of germinating seeds as materials. The results indicated: There were 28 small chromosomes in two Elaeagnus spp. which are in good agreement with previous results. The karyotype formula of E.moorcroftii is 2n=2x=28=10m+10sm+8st, the AS.K is 68.61%, and belongs to"3B"type of Karyotypic. The karyotype formula of E. oxycarpa is 2n=2x=28=12m+10sm(2SAT)+6st, the AS. K is 67.33%, and belongs to"2B"type of Karyotypic.8. Using 1-year seedlings of two Elaeagnus spp. as materials, effects of waterlogging on growth and MDA and proline content in the leaves of two Elaeagnus spp. seedlings were studied. The result showed that the proline content in the leaves of two Elaeagnus spp. seedlings rosed slowly, then rised obviously, and then decreased with waterlogging, and the peak of E. oxycarpa appeared later than E. moorcroftii. The content of MDA increased with strong stress, and it had more in E. moorcroftii than in E. oxycarpa. According to comprehensive analysis, E. oxycarpa could be considered as with higher waterlogging tolerance.9. The research of introduced two Elaeagnus spp. in Tianjin showed that the two Elaeagnus spp. had a strong adaptability under the conditions of regional climate in Tianjin. They had a strong waterlogging tolerance. They were the species of biological nitrogen fixation trees with good adaptability and ecological benefit. The main pests in Tianjin were Zeuzera coffeae Nietner, Tettig oniella viridis, Myus persicae, Lygocoris lucorμm, Hlyphantria cunea, Henosepilachna vigintioctopunctata, Clania varieata and so on.