| Loquat(Eriobotrya japonica) is an evergreen fruit tree and originated from China, which germinates in autumn, blossoms in winter, fuits in spring, and mellows in summer. There is about30species of plants of the Eriobotrya, found between latitudes20°to35°north or south, There is21species which is native to China. China is main production countries in the world, with cultivars varieties and a wealth of germplasm resources. Therefore, It is important to study genetic diversity and constructe fingerprint of Loquat, because that there are a reference value and guiding significance for preservation, appraisal and utilization the germplasm, variety innovation, and molecular assisted breeding.The experiment studied67loquat germplasm resources, using SSR primers which were developed by Fast Isolation by AFLP of Sequences Containing Repeats (FIASCO) in loquat, and SCoT primers which were developed by our laboratory and the other pepole. SSR-PCR and SCoT-PCR reaction system were established and optimized. Besides, genetic diversity of materials were analysed, and part of the germplasm resources fingerprint were construct by SSR markers. The main results of this study are as follows:1. SSR-PCR and SCoT-PCR reaction system were built and optimized, according to L25(56) orthogonal design. The results show that:(1) the best reaction system of SSR-PCR (20μL)include Mg2+1.563mmol·L-1、dNTPs0.05mmol·L-1、Taq polymerase0.75U、Primer0.750μmol·L-1and template DNA40ng.(2) SCoT-PCR include Mg2+1.875mmol·L-1、dNTPs0.35mmol·L-1、Taq polymerase2.00U、Primer0.875μmol·L and template DNA10ng.2. The loquat SSR primers which were developed by by Fast Isolation by AFLP of Sequences Containing Repeats (FIASCO) in loquat, were used in this study. The results show that the polymorphic information content (PIC) of17pairs of primer is from0.30to0.74, with average0.44. It shows that development of SSR primers of loquat has important application value.3.17polymorphic primers were selected from59primers which were developed by Fast Isolation by AFLP of Sequences Containing Repeats (FIASCO) in loquat, and53putative SSR alleles were obtained by the17primers, averaged3.12. The average of Observed number of alleles(Na), Effective number of alleles(Ne), Nei’s gene diversity(H), Shannon’s Information index(I), Observed heterozygosity(Ho) and Expected heterozygosity(He) were3.12,2.17,0.51,0.82,0.64and0.51. Similarity coefficients ranged from0.53to1.00, with average of0.765. It suggest that the genetic diversities of loquat were abundant.4.15polymorphic primerswere selected from30primers, and88putative SCoT alleles were obtained by these primers, ranged from4to9, averaged3.12. there are74polymorphic bands, with the percentage of84.09%.The average of Observed number of alleles(Na), Effective number of alleles(Ne), Nei’s gene diversity(H) and Shannon’s Information index(I) were1.86,1.55,0.31and0.46. It mean that the genetic diversities of loquat were abundant too.5. The studies showed that Eriobotrya prinoides Rehd&Wils. var. daduheensis H.Z.Zhang is more closer to Eriobotrya japonica Lindl in genetic relationship than Eriobotrya prinoides Rehd&Wils. Cultivated loquat do not cluster by color of flesh. There is a high value of DICE between ’Xingning1’ and ’Zaozhong6’, so we consider that they may be synonyms. Beside, Anhui’Dahongpao’ and Zhejiang’Dahongpao’ may be homonym.6. The results of17pairs of SSR primers’amplification in67loquat germplasm were nanlyzed. The primers of CDPP725-03/04, CDPP725-27/28, CDPP725-39/40, LM3, LM15and LM34were selected, and DNA fingerprinting of44germplasm resources were constructed by manual cultivar identification diagram (MCID).The fingerprint can effectively distinguish44materials, including cultivars25and wild19. |
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