Breadfruit is considered as the most potential food crop to solve tropical famine with high economic value. Breadfruit was introduced from several countries, and there are no research on the systematic taxonomic and genetic diversity analysis about it. The objective of this study was to specify the genetic distance and relationship among breadfruit and its closest wild relatives. For genetic diversity analysis, 33 pairs of SSR primers with clear amplified bands, high polymorphism and good stability were selected from 75 pairs of SSR primers. PCR amplification was performed, and the products were detected by 8% denaturing polyacrylamide gel. Genetic diversity correlation analysis was performed by NTSYS software. The results showed that the polymorphism ratio of amplified bands of the 33 SSR markers was 94.57%. 199 number of polymorphic sites were detected, with an average of 6.030 per marker. The PIC values of the SSR markers ranged from 0.623 to 0.940, with an average of 0.865. The genetic similarity coefficients among the breadfruit resources ranged from 0.517 to 0.951, with an average genetic similarity coefficient of 0.685. Furthermore, germplasm ZZP possessed the greatest variation among individuals, with an average genetic similarity coefficient of 0.626. Germplasm XYS1-3 possessed the least variation among individuals, with an average genetic similarity coefficient of 0.723. At the genetic similarity coefficient of 0.713, the 30 breadfruit resources were clustered into five groups, with XBL and breadnut type I (ZZP, LX, STH, HJ5) which used for landscaping clustered into one group, breadfruit SLLK, XYS2, XYS3, XYS5, XYS6 and YN clustered into one group, breadnut type Ⅱ SLM2, YDNXY1, G1 and G2 clustered into one group, breadnut type Ⅱ W1, W3, SMY, 8-4, 8-3, 5-5 and 5-6 clustered into one group. The three-dimensional diagram could better distinguish XBL and breadnut type I ZZP, LX, STH, HJ5 from the breadfruit and breadnut type Ⅱ resource with edible value. Based on the cluster analysis, we speculated that XYS2, XYS3, XYS5 and XYS6 might be introduced from Vietnam, XYS1-3, YBG and XYS1 might be introduced from Indonesia. Furthermore, FJ was regarded as a breadfruit germplasm. The present study reported the genetic diversity of breadfruit resources in China firstly, and elucidated the genetic relationship among breadfruit resources. In addition, the results could provide theoretical basis for variety breeding and identification of breadfruit complex.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |