Sampling Method for Genetic Variation Survey in Maize Populations Detected by SSR Markers
LIU Xue~*, LI Ming-Shun~*, LI Xin-Hai, TIAN Qing-Zhen, BAI Li, ZHANG Shi-Huang~(**)(Institute of Crop Sciences, Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Genetic & Breeding, Ministry of Agriculture, Beijing 100081, China)
Genetic diversity in maize (Zea mays L.) plays a key role for future breeding efforts. Diallel analysis was used commonly to detect the genetic variation among or in maize populations, which makes great efforts to facilitate hybrid deve-(lopment). In recent years, molecular markers are convinced as a powerful tool in detecting the genetic diversity among maize inbred lines, while it remains under investigation and optimization in analyzing maize populations. The objectives of the current research were to use SSR to (1) compare the genetic information analyzed with different bulking DNA samples, and (2) establish the technique procedure to detect genetic variation in maize populations. The modified CTAB method was used to extract DNA of 50 individuals of each population and DNA samples from leaf mixture of 5, 10, 15 and 20 individuals, respectively. 17 SSR primers selected from 10 chromosomes of maize were employed for PCR amplification of DNA samples from leaf mixture. PCR products were separated in denaturing polyacrylamide gels in 1×TBE buffer, 2 μL of each PCR product were pooled. The results showed that the DNA from leaf mixture of 10 individuals was identified to be the best choice to replace the DNA mixture from the same number of individuals through comparing the number of alleles, polymorphism information content value and diversity index (Table 2, 3), and allel number amplified with the DNA samples from leaf mixture of 5 and 10 individuals was significantly correlated with that with DNA mixture from the same number of individuals in two populations (Pob69: r=0.913 and 0.913; Pob70: r=0.909 and 0.869; P0.05; Table 4). In addi-(tion,) the results of PCR amplification among DNA samples from leaf mixture and the mixture sample of individual DNA were compared and showed that the DNA samples from leaf mixture is the optimum substitute for the mixture sample of individual DNA (Table 5). Finally, the DNA extracted from leaf mixture of 10 individuals was confirmed as a labor saving and efficient approach to analyze the maize population diversity. Now the bulking fingerprinting method has been adopted to analyze the genetic relationships among maize populations with polyacrylamide gel electrophoresis.
【Fund】： 农业部948重大国际合作(Q20033);; 国家自然科学基金(30300223);; 亚洲玉米生物技术协作网项目资助。
【CateGory Index】： S513
【CateGory Index】： S513