玉米耐旱功能标记辅助选择初探

干旱是影响玉米生产的主要因素之一,培育耐旱品种可以有效地保持其在干旱环境下的产量稳定性。随着生物信息学数据库的不断完善及基因组学技术的发展,耐旱通用QTL(Quantitative trait locus)的发掘为分子育种提供了新的机遇和方法。本研究在已发掘的耐旱通用QTL基础上,选取相关的18个连锁标记进行开发并且验证在不同种质背景下24份玉米自交系的耐旱性。结果表明,共检测出42个多态性位点,平均多态性信息量为0.4245;通过GGT32(Graphical GenoTypes)图示基因型软件分析SSR位点,得出umc2217、umc2029、phi099、umc1213和phi022这5个连锁标记可用来初步鉴定玉米耐旱性;利用卡方检验,得出phi022和umc2217均达到显著水平,其与耐旱密切相关。因此,这几个连锁标记不仅可被用于相应群体的耐旱分子标记辅助选择,而且为以后的标记辅助选择及抗旱性基因克隆的研究打下基础。

An Initial Analysis of Functional Marker-Assisted Selection with Drought Tolerance in Maize

Drought is one of the main factors affecting maize production, and development of new cultivars with high yield stability under water stress is a major breeding objective. With the enrichment of bioinformatics databases and development of genomic technology, progress on identification of the consensus drought-tolerant QTLs provide new approaches and prospects for molecular breeding of drought tolerance in maize. According to our previous study, some important constitutive and adaptive QTLs using meta-analysis were identified and to find specific genes and their families for speculating on drought tolerance networks. The objective of this study was: on the basis of excavated drought-tolerant universal QTLs, we selected 18 linked markers to develop and verify the drought tolerance in 24 different germplasms. The results were as follows: (1) 42 polymorphism sites allelic variants were detected and a mean polymorphism information content of 0.4245, with a range of 0.0799 to 0.7170. (2) By GGT32 analysis, five linked markers (including umc2217, umc2029, phi099, umc1213 and phi022) showed significant variations among different germplasms, which may be initially used to identify different drought-tolerant materials. (3) Using the analysis of chi-square test, we found that linked markers phi022 and umc2217 have reached significant levels, which might be closely related to sites of drought tolerance. Therefore, these linked markers can not only be for the corresponding groups of drought-resistant marker-assisted selection, and lay the foundation for future marker-assisted selection and drought resistance gene cloning.