| Dalbergia cochinchinensis Pierre is a semi-deciduous precious rosewood of papilionoidea dalbergia with an aggregative function of high gloss,high strength,corrosion resisting and good processing perfomance,commonly known as Red Suanzhi.To research the characteristics of seed,the performance of seeding growth and the comprehensive evaluation of early seeding quality,we used Dalbergia cochinchinensis Pierre seeds collected from 10 provenances in Thailand,Cambodia and China as the basis material,revealed the geographical variation of phenotypic traits,and the quality classification and evaluation of the seedings were also carried out.Finally,we selected the superior provenance preliminarily,and provided a certain theoretical support for Dalbergia cochinchinensis Pierre in the work of suitable introduction,genetic improbasis for introduction to the appropriate regions and further improvement of genetic improvement and conservation of germplasm resources in China.The main results were as follows:(1)There were significant differences in seed phenotypic traits among the 10 populations.The variation of seed length,width and thickness reached a very significant level in the provenance.1000-seed weight ranged from 15.80 g to 33.76 g.The phenotypic traits of the seeds were negatively correlated with the longitude,latitude,altitude and precipitation,but the correlation was not significant.The germination rate of seeds had highly significant differences among the provenances,the sowing lands respectively(P<0.01).The correlation between 1000-seed weight and germination rate were not significant(P>0.05),which showed nagetive correlation of a certain level.It was showed the highest average germination rate in Yangjiang.Seeds from ‘Prachin Buri’ had the highest average germination rate in 4 regions,up to 83%.Based on the cluster analysis of seed traits,the 10 species could be divided into 3 categories,and the variation of seed phenotypic traits was not continuous in geographical space.(2)The difference of seedling traits among different provenances was significant,the test showed that the best performance of seedling height was ‘Nakorn Rachassima’,the best performance of ground diameter was ‘Phitsanulok’,and the worst performance of seedling growth was ‘Kampong Cham’.The growth traits were controlled by latitude,longitude,low temperature and annual rainfall.Its geographical variation had obvious climatic and ecological characteristics.According to the clustering of the seedling traits of the provenances,the 10 species could be divided into 4 groups,and the group had a distinct geographical pattern.(3)Based on principal component analysis and correlation analysis,the main indexes for evaluating the quality of 1-year-old seedlings of Dalbergia cochinchinensis Pierre were selected,and implemented seeding classification by seeding height and ground diameter.After 1.5 years of afforestation,the survival rate of I and II seedlings was more than 90%.In mean ± standard deviation,6.02% of grade I seedlings transferred into grade III,only 1.03% of grade III seedlings transferred into grade I.In k-mean clustering,16.57% of grade I seedlings transferred into grade III and 14.81% of grade III seedlings transferred into grade I.Mean ± standard deviation method was identified as classification of 1-year-old Dalbergia cochinchinensis Pierre seedling,and the grading standard was as follows: grade Ⅰ,H≥121.20 cm,D≥7.57mm;grade Ⅱ,70.80cm≤H<121.20 cm,4.94mm≤D<7.57mm;grade Ⅲ,H<70.80 cm,D<4.94 mm.(4)Factor analysis is a multi-analysis method for multi-character joint selection evaluation,combined with correlation analysis and cluster analysis,the classification and comprehensive score evaluation of 10 provenances of Dalbergia cochinchinensis Pierre were carried out.The preliminary mathematical model of provenance evaluation had been set up,which provided a certain theoretical basis for the early selection of the provenances.Each one has its good points in phenotypic traits,we should take the matter on its merits when selecting target provenance.‘Kampong Cham’ could be used as an alternative. |
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