Study On The Promoting Blossom And Bear Fruit Techniques Of Pinus Sylvestris Var. Mongolica

Combined with the habitats of origin, the Pinus sylvestris var. mongolica from HuoLuoforest farm Inner Mongolia Autonomous Region was used as the experimental material to studyon the problem of less flowering and less fruiting at environmental and physiological level byobserving the development process of cone, and try to find out the measures of increase itsoutput.The results were as follows:1.Compared with the origin soil, the Pinus sylvestris var. mongolica planted forests fromintroduction area in soil organic matter content, nitrogen content and phosphorus content wererelatively low, so the optimum dosage of these nutrient could be determined in fertilizingexperiment. In addition, the annual average temperature, annual average sunshine duration,annual average frost-free period and≥10℃annual accumulated temperature were all higher thanthe origin, but the average annual rainfall, annual average wind speed was less than the origin,these factors affected the blossom and bearing fruit of Pinus sylvestris var. mongolica.2.The microsporophyll primordium formed around July20th, then the microsporangium cellformed in mid August. After the winter dormancy, it entered into the stage of meiosis from nextyear in late April, the mature time of pollen grain was on around May7th. The formation of theovulate strobilus primordium was on around August5th, then divided rapidly, the bud scaleprimordium and axis formed in the middle of August, The next year in early May, the bract scaleprimordium was began to differentiation, the ovulate strobilus primordium tend to completearound around May20th, then the ovule formed.3. In the early period of the flower bud differentiation on Pinus sylvestris var. mongolica,endogenous hormone content of IAA, ZRs, ABA in the female flower bud were all in a slowrising state, when IAA content was in the highest peak, the female flowers bud was being into thebract scale primordium differentiation stage, When ZRs content was in the highest peak, thefemale flowers bud was being in the early bract scale primordium differentiation stage, thecontent of ABA was at its peak with the female flower bud differentiation completed, after that itbegan to decline, but remained at a high level. The content of GA in the female flower bud wereat a low level in the early flower bud differentiation, and declined slowly, it didn’t sharply riseuntil mid-April of the following year, to the bract scale primordium differentiation completed itscontent began to decline.4.The fertilization experiment showed that, each fertilizer treatments could increased thenumber of male flowers, female flowers and1year old cones, it means fertilization is a practicalmeasure, Among all these measures first year the best result was treatment3which contained1kgper tree urea,0.1kg per tree superphosphate and10kg per tree bio-organic fertilizer, it couldincreased the female flowers by68.9%, the male flowers by69.5%,1year old cones by143.1%, it could provided guidance for the future fertilization. Fertilization still had a promoting effect onthe number of flowers in the second year, and the range for promoting male flowers was largerthan the range for promoting female flowers.5.The hormone spraying experiment showed that, the influence of different concentrationhormone treatment on Pinus sylvestris var. mongolica blossom and bearing fruit characterized bypromoted at low concentration, while had inhibitory effects at high concentration, In GA4+7spraying experiment，the most obvious effect to increase flowers and cones was500PPMconcentrations of GA4+7treatment, the number of1year old cones in treatment group was57.4%more than the control group, and had the largest increase, an average of15.75per branch moremale flowers, increased by51.6%, and an average of2.28per branch more female flowers,increased by16.3%；In6-BA spraying experiment, the most obvious effect to increase flowersand cones was250PPM concentrations of6-BA treatment, the number of average female flowers,male flowers and1year old cones in treatment group was22.2%,42.7%and31.8%more thanthe control group.