Studies On The Characteristics Of Seed Germination And Seedling Growth Of Stranvaesia Davidiana

Stranvaesia davidiana has a dense canopy and a bright green foliage.And in autumn it is filled with red fruits and red leaves for a long time.Moreover,it is a landscape tree with a good ornamental value of flower,fruit and leaves.At present,there is no reports on the introduction,acclimatization,propagation techniques,exploitation and utilization of Stranvaesia davidiana in China.As a result,the studies on characteristics of seed germination and seedling growth of Stranvaesia davidiana can provide references for reproduction and cultivation of Stranvaesia davidiana and can make a difference in enriching the diversity of urban landscape trees.Taking Stranvaesia davidiana seeds as experimental materials,the researcher collects the data of germination rate,germination potential and initial germination period of Stranvaesia davidiana seeds to study the germination characteristics of Stranvaesia davidiana seeds under different temperatures,different GA₃ concentrations and substrate conditions.Based on the experiments of annual seedlings of Stranvaesia davidiana,the data of plant heights,base diameters and relative chlorophyll content?SPAD?are collected to study the annual seedling growth characteristics under different shade conditions?<20%of full light?and different fertilization conditions.The main conclusions are as follows:?1?Stranvaesia davidiana belongs to pome.The seed colors vary from tawny to brown and seeds are long and round whose surface is uneven and odorless.The weight of 1000 seeds is?3.594±0.080?g,and the length of longitudinal axis is?0.398±0.006?mm,and the length of transverse axis is?0.190±0.003?mm.?2?Different temperatures have significant effect on the germination rate,germination potential,initial germination period and germination duration of Stranvaesia davidiana?P<0.01?.With the increase of temperature,the germination rate and germination potential increase first and then decrease,and the length of the initial sprouting period decreases first and then increases.At 10?and 30?,the germination of seeds is poor,and high and low temperatures are not conducive to the germination of Stranvaesia davidiana.At 25?,Stranvaesia davidiana seeds have the highest the germination rate?43.33%?and germination potential?26.67%?,as well as the shortest initial germination period?9 d?.?3?Different concentrations of GA₃ have a significant influence on the germination rate of red Stranvaesia davidiana and its initial germination period?P<0.05?,but barely no significant influence on the germination potential.With the increase of concentration,the germination rate and germination potential increase first and then decrease,and the length of the initial germination period decreases.High concentration of GA3 is not conducive to the germination of Stranvaesia davidiana seeds.The treatment of GA₃ can effectively promote seed germination.Under the condition of 400 mg·L^-1 GA₃,the germination rate?60.67%?and germination potential?35.33%?are the highest,and the initial germination period is the shortest?6.6d?.?4?Different substrates have no significant effects on the germination rate and germination potential of the seeds of Stranvaesia davidiana,but have a significant effect on the initial germination period of the seeds of Stranvaesia davidiana.Under the three different substrate conditions,the initial germination period and germination initiation of the river fine sand are the shortest,but the seedlings are prone to lodging.The germination initiation of perlite:peat soil=1:1 is the slowest,but the germination is the best.?5?The total growth of plant height,base diameter and SPAD of Stranvaesia davidiana are significantly affected by shading.The total growth of growth index in shading group?low light?is significantly lower than that of control group.Low light?<20%of full light?would restrict the growth of Stranvaesia davidiana seedlings.The increase of SPAD of leaves tends to decrease,which is negative from November to December.?6?Single factor results show that different fertilizer types have significant effects on the total growth of plant height,SPAD and base diameter.Different fertilizer nitrogen contents of same fertilizer types have significant effects on the total growth of plant height,base diameter and SPAD;two-factor variance results show that the interaction of fertilizer types and nitrogen contents have significant effects on the total growth of plant height,base diameter and SPAD.The effect of organic fertilizer is the best at low nitrogen level,followed by inorganic fertilizer,and nitrogen fertilizer.However,the organic fertilizer at high nitrogen level is not conducive to the growth of Stranvaesia davidiana.Under the experimental conditions,the application of Stanley organic fertilizer?45%organic matter,5%nitrogen,5%phosphorus,5%potassium,5%?is the best with 4.06g per pot per year.