Studies On The Biology And Genetic Relationship Of 'Guifengzao'(Dimocarpus Longan Lour.)

This article focused on the biological characteristics of 'Guifengzao'(Dimocarpus longan Lour.),at the same time,Shixia and Chulian(Dimocarpus longan Lour.)were taken as CK.The study included a comprehensive and systematic investigation and studies of shoot growth habits,flowering outcome habits and phenology periods.In this study,the genetic relationship between 'Guifengzao' and the main longan varieties in Guangxi and the main early and late season longan varieties in and out of the Guangxi were compared and analyzed.The results of the study indicated that:1.'Guifengzao' is a variation plant of seedlings.The tree of the species is prosperous with round-headed crown,open shaped and think and strong shoots.Its main trunk had thick bark with gray-brown in colour and irregular cracks;Peripheral branches of tree crowns hang slightly.Its leaves are pinnate,with 4-5 pairs of leaves per compound leaf,lobule opposite,dark green in color,bright leaf surface,oblong to lanceolate,slightly wavy margin with twist at the apex.The leaf base is asymmetrical wedge or broad wedge,and the tip of the compound leaf is pendulous.The matured twigs of Guifengzao are light brown in color,with bulging yellow-brown spots on them,similar to Chuliang,but the whole leaf is smoother than Chuliang.2.The flower panicles of 'Guifengzao' are relative larger,about 28-35cm long with cone-shape.The density of the flowers is slightly less than that of Shixia,similar to Chuliang longan.The female stigma of Guifengzao'is forked or 'r' shaped.Petals were fresh white,and the flowering period is slightly earlier than that of Shixia.The flowering habits are often expressed as 'Male-Female-Male '.There are also a small number of flowering spikes which female flower opened first.That is,the order of flowering is female-male-female-male.The male and female flower overlapped for a long time.'Guifengzao' is very early season strain with high-yield and high quality.Its mature period is 7-15days earlier than that of Shixia and 20-30days earlier than that of Chuliang under the same cultivation conditions.The average individual fruit was lager than Shixia,weighing 11.26g with uniform size and bright skin color compared with Shixia.The average mononuclear weight was 1.62g,the average edible rate was 71.31%(74.0%of the highest),and the soluble solids content was 21.9%of(25%of the maximum).The inflorescence primordium emerged in early of January,the heading period was in early February.The flowering period was from mid-March to early April in Longzhou County of Guangxi.The most outstanding specialty of 'Guifengzao' is its very-early-season,it can be harvested by the end of June to early of July.This excellent strain is suitable to grow in longan production areas.3.In this study,the phylogenetic relationships of 15 Longan Germplasm resources were analyzed by SCoT molecular markers.From the 80 SCoT primers,14 primers with good amplification effect were used to amplify 15 genomic DNA of longan germplasm.A total of 144 bands were amplified,of which 103 were polymorphic.The proportion of sex was 71.53%,and 10.29 bands were amplified per primer.The UPGMA clustering results showed that the genetic similarity coefficient between 'Guifengzao' and other 14 tested varieties was ranged from 0.75to 0.88.With a similarity coefficient of 0.76 as the boundary,the 15 varieties could be divided into three groups of A,B and C.Among them,the closest relationship with 'Guifengzao' was cv.Dongbi,the genetic similarity coefficient was about 0.85.The use of 14 primers can distinguish the'Guifengzao' from 14 other materials in the test.There was no synonym relationship.Therefore,it can be concluded that 'Guifengzao' is a new species different from the above-mentioned test varieties.