Core Collection of Cassava ( Manihot esculenta Crantz) Germplasm

[Objective] This paper aimed to construct the core collection of cassava germplasm. [Methods] Parameter values of six traits of 161 clones were ana-lyzed and evaluated. [ Results] Minkowski genetic distance was established for cluster analysis of core collection. Preferred sampling method （D 2C5S3） was suit-able for the construction of the core collection of cassava. A total of 25 core collections were obtained, which accounted for 15% of the original germplasm and could represent the genetic diversity and integrity of the original germplasms. Meanwhile, it reflected that the genetic background of the tested cassava germplasm was nar-row and the range of genetic diversity was quite small with genetic redundancy. [ Conclusions] Constructing core collection provided a theoretical foundation for the protection and utilization of cassava germplasms.

A Study of Genetic Polymorphism of Cassava Germplasms and ISSR Molecular Markers

[ Objective] This study aimed to analyze the genetic potymorphism of 39 cassava varieties （lines） preserved in Guangxi Zhuang Autonomous Region Research Institute for Subtropical Crops. [ Method ] ISSR primers with good polymorphisms and amplification effects in cassava were selected for PCR amplification of 39 cassava germplasms, statistics and analysis of the amplified bands were conducted. In addition, cluster analysis was conducted by using UPGMA method based on the genetic similarity among cassava varieties （lines）. [ Result] Ten pairs of ISSR primers were selected. A total of 70 clear electrophoretic bands were amplified, each pair of primers had amplified 3 -9 electrophoretic bands, with an average of 7, and the length of amplified bands ranged from 150 to 2,000 bp; cluster analysis showed that 39 cassava varieties （lines） were clustered into two categories by the similarity coefficient of 0.67 ; in addition, the genetic distance among cassava was very narrow, with genetic similarity coefficients ranging between 0.80 and 1.00. [ Conclusion] This study laid foundation for breeding of high- cmalitv cassava in China.

Development and prospect of telemedicine

With the continuous improvement and development of modern network information technology and the continuous improvement of people’s demands for health care,the traditional health care model has evolved,giving birth to a new telemedicine health care model.Telemedicine refers to the comprehensive application of information technology for medical information transmission and long-distance communication between different places.It integrates medicine,computer technology,and communication technology for remote monitoring,diagnosis,consultation,case discussion,teaching,and surgery as well as a series of medical activities.With the continuous development of communication technology,telemedicine is also constantly changing.As a relatively novel technology,telemedicine is sought after by major hospitals.With the advancement of internet technology,digitization and informatization have been gradually applied in telemedicine,but due to various factors,telemedicine still has great limitations.This paper summarized the development status of telemedicine;discussed in detail the development of telemedicine at home and abroad;reviewed the application of telemedicine as well as the feasibility and limitations of its promotion and development;and put forward an outlook for the future development of telemedicine.