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Papaya (Carica papaya L.) origin of tropical America, is a tropical and subtropical fast-growing dicotyledonous, multi-gender perennial evergreen fruit trees, small genome (2n = 18), the famous fruit in southern China, is one of the Lingnan good fruit. Into China in the 17th century, more than 300 years of history of cultivation in China are mainly distributed in Guangdong, Guangxi, Fujian, Taiwan, Hainan and other provinces, autonomous regions. Papaya nutritious, containing iron, calcium and many trace elements and rich in vitamins A and C, has a role in health care; immature fruit with half-cooked fruit and leaves are rich in papaya enzyme can aid digestion; the papaya's all green the part contains a carpaine, for medicine; chymotrypsin contained in papaya is widely used in the food industry, medicine, tanning, beauty products; papaya has a very wide range of uses and economic value in the international very popular on the market. By the breeding means of access to quality, high yield papaya varieties of papaya industry means necessary. For a long time, the study of of papaya germplasm resources in China lags behind the breeding practices, lack of research on various types of local resources or ecological type on the genetic differences existing papaya varieties of genetic diversity. Domestic papaya is mainly confined to the external morphological and agronomic traits, and less from the level of cytogenetic and molecular genetic study of the papaya existing germplasm and the introduction of germplasm, these results papaya germplasm resources can not be effectively use, there is a great blindness, affecting the efficiency of the breeding hybrid parent selection. Papaya varieties (lines) mostly take the naming rules of origin and fruit traits composite named most likely to cause a synonym or homonym phenomena. Usually papaya seedling breeding, and thus there will be some male plants in the breeding process, this is not only wasteful production, seed saving and male plants of orchards to make a large number of male plants after breeding seedlings, only 6 the results period from morphology to eight months after the papaya flowering plants accurately determine gender to male plants of whole chopped in addition. This paper combines the above aspects, using RAPD and SCAR Markers, 17 papaya germplasm resources for the study of the object, and analysis of their genetic diversity, and to carry out gender early identification of genetic breeding papaya and gender identification of molecular biology research-based information, the main results are as follows: use of RAPD technique stable amplification of 16 primers screened from 214 primers, 17 papaya varieties (lines) were amplified amplified a total of 120 bands, 77 were polymorphic, the polymorphism of the proportion of 64.17%, an average of seven bands per primer ranged from 5 to 10, the band size of 180 ~ 1800bp . RAPD amplification results the unweighted paired Mean algorithm (UPGMA) cluster analysis of 17 papaya varieties (lines), the results showed that the genetic distance between 0.05 to 0.23, 0.17 level divided into four categories. Xiang Fei and Thai red meat each class; the Zhongcun the 3rd, Zhongcun Tainung Charan four varieties for a class; spike in the Red, Red Princess, Red Bell, Sunrise, TNG No. 2 the Lingnan species-GY, the United States and the new century, Red Honey, Honey 11 varieties of poly fourth major. RAPD technique to identify papaya varieties and analysis of genetic diversity of germplasm resources practicable. RAPD and SCAR Markers technical appraisal papaya male gender. 214 random primers, using primers Z18 amplified with a size of approximately 1kb male polymorphic fragments exist in this fragment test gender strains in the material of all male plants and female plants not named Z18 -1000. Z18-1000 recovered, cloned and sequenced by of papaya male RAPD markers, there is obtained the specific sequence of nucleotides labeled, is composed of a lot of the nucleotide sequence of 1001bp, this sequence has been Genbank Accession the logon No. DQ787854. The re-designed two pairs of primers RAPD markers successfully converted into SCAR marker, and was named SD-1000 based on sequence analysis of the fragment.
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