| In order to widen the genetic background,and to screen the target characteristics at early development stage for Swida wilsoniana.In this paper,different parents and F1 offspring produced from 7 crossing combinations were used as the experimental materials.By means of multiple comparison of morphological traits,phenotype distribution,the diversity characters of hybrid fruits and seeds,growth characters of one year,two years and three years old F1 offspring seedlings,the correlation and the broad-sense heritability of those characters were analyzed;Meanwhile the anatomical structure of stems and leaves from different seedlings of F1 offspring was conducted.Further,using orthogonal design and single factor optimization,SSR-PCR reaction system for SSR molecular marker was established,and the polymorphism primers were screened,so as to provide a vital basis and technical support for analysis of genetic diversity,establishment of genetic maps and molecular marker assisted breeding for S.wilsoniana.The main results were as follows:1.Characters of fruits and seeds among different crossing combination were diversity.Their variation coefficient were 5.46%～22.17%.Variation of thousand fruits weight were significantly larger than that of vertical,longitudinal diameter and oil content.Germination rate was significantly uneven among different crossing combinations,and their variation coefficient was 40.43%.The highest germination rate was the seeds produced from combination of ♂B08 ×♀A03(41.67%),while the lowest germination rate came to the seeds of ♂806℃♀B03(14.81%);There had a positive correlation among traits of hybrid fruits and seeds,and their correlation index was 0.608～0.930.Of those,the germination rate positively correlated with seed vertical diameter,fruit vertical diameter,thousand-fruit weight significantly.That was fruits and seeds characterized with plump,larger vertical diameter,as so long with larger vertical diameter seeds,which have high germination rate.2.The increment pattern of height and base diameter of F1 1a offspring seedlings was "slow～fast～slow" increase.However the difference in height and base diameter growth among one year old seedlings from different crossing combination were extremely large,which resulted from the duration of the fast growth period;For 2 or 3 years old seedlings of F1 offspring,the correlation among height,base diameter and inter-node length was significant positive,that was of any positive selection from the three traits,it would be able to improve the other two traits;Leaf width was significantly associated with base diameter of third years old seedlings.Moreover,the broad-sense heritability of leaf width is relatively stable then,that meant,leaf width,to a certain extent,could be a parameter of selection target trait in early seedlings stage.3.Anatomical structure of stem and leaf had positive correlation with vegetative growth of F1 offspring.The Cross section area of stem mostly attributed to the woody area.Plant height positively related with stem cross section area significantly,and then positively related with cross woody area very significantly.The base diameter and total leaf thickness,sponge tissue thickness had extremely positive correlation respectively.The woody area and sponge tissue thickness could be used as main anatomic structure index to predict potential growth of F1 seedlings.4.Optimized SSR-PCR reaction mixture was established as follows:15μL total volume including 37.5 ng template DNA,0.6μmol/L forward and reverse primers respectively,0.4 mmol/L dNTPs,1.5 mmol/L Mg2+ and 1.0 U Taq DNA polymerase.And optimum annealing temperature of primers Cf-05 was 50℃;These factors restricted SSR-PCR in sensitivity,specificity and production,but their contribution ratio of influence was different.Contribution ratio to influence ranked as:primer concentration>Taq polymerase>DNA template amount and concentration of dNTPs>Mg2+ concentration;Based on the reaction system,11 SSR primers were screened,which were doable for SSR-PCR reaction system. |
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