| In this article,the differences of morphologic and physiological parameters under natural cooling-off conditions of two-year-old seedlings of six different provenances Dalbergia odorifera T.chen were studied,to evaluated the cold tolerance of the different provenances seedlings,which seedlings introduced from WenZhou?XianYou?PingXiang?SanYa?GuangZhou?ZhangPu.The growth rhythms of six different provenances seedlings were studied,the techniques of sowing and light-fertilizer intensive cultivation were also studied.The results of the studies as follows,which will provide theoretical basis and technical support for introduction and cultivation of D.odorifera.1.The growth rhythms of six provenances seedlings are almost the same.The peak period of increment in height is May to June,and the period of increment in ground diameter is July to August,the growth of ground diameter later than height growth.After September,the growth in height almost stop and the growth in ground diameter grew slowly.The growth of height and ground diameter are both biggest in SanYa provenances seedlings,which grows 41.46 cm and 6.32 mm respectively,and the second biggest of growth of height and ground diameter are 34.78 cm and 6.31 mm in XianYou provenances seedlings respectively.The ratio between growth in October to November and total growth in one growing season are highest in WenZhou provenances seedlings,while the ratio of height is 3.53% and the ratio of ground diameter is 12.68%.The growth situation of WenZhou provenances seedlings interpret that the WenZhou provenances seedlings have accommodated the climate of WenZhou,which have a certain growth in the period of low temperature.2.According to comprehensive analysis of the indexes of morphological and physiological of the six different provenances seedling,the Wenzhou and Xianyou provenances seedling have best cold tolerance,Pingxiang and Sanya provenances seedling have the worst cold resistance.This resultion prove positive correlation between the cold resistance and the the latitude of introduction area,the better cold tolerance is in the seedling form the introducing region of higher latitude.3.The germination test in seven matrixes shown that the matrix of yellow subsoil and peat soil are the best matrixes of germination of D.odorifera,which bring the maximal germination rate,germination potentia,seedling rate and the shortest germination days.The four foregoing indexes with the matrix of yellow subsoil are 72.7%,49.3%,69.71% and 12.7d corresponding,and that in peat soil are 68.0%,53.35%,74.15% and 13.0d.The matrix of pure river sand is the worst matrixe of germination.In conclusion,yellow subsoil or peat soil should be used in germination of D.odorifera.4.Orthogonal experiment of L9(34)were designed and analysed from 3 levels of concentration of GA3,soak time and seed treatment.The study shown that the best combination for germination of D.odorifera is the seeds without pod soaked for 6 hours in 40 mg·L-1 GA3,which bring the germination rate at 86%.The seeds have low germination rates with 0 and 80 mg·L-1 GA3,that is to say,the low or high concentrations of GA3 are unfavorable to germination.The germination rate of seeds without pod is significantly higher than two other treatments,and there is no significant differences between the latter two treatments.5.In this study,D.odorifera seedlings were cultured with conventional and exponential fertilization treatments at rates of 2 and 4 g and an unfertilized control under the natural photoperiod and the extended photoperiods with supplementary lighting for 3h and 6h.Seedlings under the extended photoperiods had greater height but less root-collar diameter than those under the natural photoperiod.In conclusion,the extended photoperiod of supplementary lighting for 3h was recommended for the culture of D.odorifera seedlings and the exponential fertilization resulted in the better nutritional status to the conventional fertilization. |
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