Study On The Regularity Of The Blooming And Seed Bearing Of Superior Type And The Construction Of RAPD Fingerprint Of Xanthoceras Sorbifolia

The phenophase, blooming habits and fruiting rules, the drop situation of flower andfruit of30Xanthoceras sorbifolia were observed and analyzed in the nursery of Yangling. Atlast,6superior type of Xanthoceras sorbifolia were rechoosed and RAPD fingerprint werestructured. The main results are as follows:(1) Phenophase and the drop situation of flower and fruit.The fruit of Xanthocerassorbifolia of Yangling need about90days from shaping to ripening, they can be planted tothose places where have the same or similar conditions.The proportion of fertile flower isvery low, only17.35%,about65%Xanthoceras sorbifolia ranges from10.2%to31.63%.The drop rate of flower and fruit was95.35%in Yangling, the phenomenon of fallenpetal mainly focus on the end of flowering. The phenomenon of fruit drop lasts about onemonth or even more. After this period the rate become less, but always accompany the fruitgrowth development period. The fruit setting rate is4.65%. The phenomenon of fruit dropmainly within20days after the fruit began to swelled. At the end of May and June, the trendof fruit drop become gradually stable.(2)The research of fruit growing development progress.The growth and development offruits mainly within30days after fruit ovary enlargement period. From the beginning of Mayto early July, during the two months, the fruit growth faster in the first one month, its averageincrement rate reached305.3%,but in the next month, the average increment rate was only7.7%. The average length of fruit always bigger than the breadth during the whole growthprocess and the difference is smallest around the first12days when fruit ovaryenlargement.However,the breadth of fruit grew always faster than the length.The Aspect ratiowas biggst at the early stage of fruit ovary enlargement,about1.31,the nutrient was mainlyused for the growth of length.The Aspect ratio around1.07in June.(3)The analysis of the fruit characteristics and the distribution rule. More than50%ofthe fruits are solitary,a string of fruit always have2to4fruits,and95.3%of the total amountare dehiscent fruit which with three lamellas.The distribution of fruits on the tree was asfollow: for different direction of the tree-crown,south has the most fruits which is34.8%oftotal amount; for different position,45.8%of fruits are on the upside,which is triple of thedownside, and84.3%of them are on the upside and middle part of the tree; for different age of branches, four-year-old and five-year-old branches have most while one-year-old ortwo-year-old branches rarely.(4)The rechoose of superior type.According to the selection criteria of superior type,6superior type of Xanthoceras sorbifolia were rechoosed, the selected ratio is20%,the selectiondifferential of the height of tree, ground diameter, branch height, the proportion of fertileflower, the average number of fruit per tree and the average yield per tree is11cm、0.75cm、-3.47cm、11.43%、12.7and0.53Kg.(5)The study of RAPD fingerprint.The advanced CTAB methods can be used to extractthe DNA of Xanthoceras sorbifolia, the value of OD260／OD280from1.7to1.9,which can beused for PCR and RAPD analysis.91bands were produced using the10primer and thenumber of polymorphic bands were77,each primer can produce7.7polymorphic bands,thepercentage of polymorphism was from62.5%to100%,the average proportion was84.6%.According to the electrophoretogram constructed by S279and S285primer, superiortype can be identified effectively.