Research Generative Biological Characteristics Of Malus Sieversii (Ledeb.) Rome.

The generative biological characteristic of Malus sieversii(Ledeb.)Rome. were growing in XinJiang YiLi was tested. The paraffin cut section method was adapted to observe the developing process of Malus sieversii flower bud differentiation. The effects of different storage conditions and different concentration of sucrose were studied on Malus sieversii pollen vitality. Pollination test had been done in different individual tree. Pollen morphology were examined with scanning electron microscope(SEM). The effects of seed-coat, stratification time and different hormone on seed dormancy and germination were studied on Malus sieversii seed. The main results as follow.1. The flower bud differentiation of Malus sieversii started in late June. The whole process was from the beginning of the flower bud differentiation to the pistil primordial differentiation approximately lasted for 70 days. The whole process may be divided into pre-differentiation stage, the early differentiation stage, sepal primordial differentiation stage, petal primordial differentiation stage, stamen primordial differentiation stage and pistil primordial differentiation stage. Pistil primordial differentiation finished at the beginning of September.2. In normal temperature, the pollen of Malus sieversii stored within 3 days possessed high vitality and the average germination reached 58%, pollen vitality decreased obviously in 5 days, the average germination reached 37%, the average germination only reached 1% after 30 days hardly germinate. The pollen which was stored in 4℃within 10 days was quite well. It still had certain pollen vitality after 130 days. Sucrose could promote germination obviously. The concentration with 15% of sucrose was better than other. Individual differences among the pollen vitality were found.3. The fruiting hadn't been found after used two treatments that self-pollination and unisexuate. Pollination insects will affect the fruit-set obviously. The result of fruit set percentage in five treatments from high to low as follow: cross-pollination, natural condition pollination, plastic net bag isolate insect pollination, self-pollination and unisexuate.4. The pollen of Malus Sieversii shapes long and prolate,with 3-colpi and 3-zonotreme in the middle of the colpi. The colp-orate belonged to N3P4C5 type, exine striate-favolate pattern.5. The stratification could break dormancy effectively. The percentage of germination with seed-coat reached 90% stratified seeds 75 days. Seed-coat could inhibit germination obviously. The percentage of germination with seed-coat was 8% and 90% without seed-coat stratified seeds 45 days. GA3 was helpful for breaking dormancy without seed-coat. It was a befitting treatment for breaking dormancy peels seed with 500mg/L GA3 stratified seeds 30 days. The effect of GA3 and 6-BA with seed-coat was not obviously. Germination percentage had difference in different individual tree at the same treatment.