陕西小麦品种(系)脂肪氧化酶活性基因的遗传多态性分析

Genetic Polymorphism of Lipoxygenase Genes in Shaanxi Wheat Cultivars and Lines

为给小麦品质改良提供理论依据,利用1A染色体上QLpx.caas1-AL位点的标记Xwmc312及基于4B染色体上TaLOX-B1位点开发的显性互补功能标记LOX16和LOX18,对173份陕西小麦品种(系)进行检测,分析LOX活性基因的遗传多态性。在QLpx.caas1-AL位点,所检测的陕西小麦品种(系)存在Xwmc312-227、Xwmc312-235和Xwmc312-247三种等位变异类型。其中,Xwmc312-227类型有54个,占31.21%;Xwmc312-235类型有31个,占17.92%;Xwmc312-247类型有88个,占50.87%。在TaLOX-B1位点,所检测的品种(系)存在TaLOX-B1a和TaLOX-B1b两种等位变异。其中,TaLOX-B1a类型有39个,占22.54%;TaLOX-B1b类型有134个,占77.46%。两个位点在陕西小麦中存在6种等位变异的组合类型,其总体分布比例不同,以Xwmc312-247/TaLOX-B1b组合类型品种(系)的分布比例最高(41.0%),其次为Xwmc312-227/TaLOX-B1b(19.6%)、Xwmc312-235/TaLOX-B1b(16.8%)、Xwmc312-227/TaLOX-B1a(11.6%)和Xwmc312-247/TaLOX-B1a(9.8%),而以Xwmc312-235/TaLOX-B1a组合类型品种(系)的分布比例最低(1.2%)。6种等位变异组合类型的分布比例在陕西不同麦区也存在差异。在陕西小麦中,低LOX活性等位变异品种(系)的比例明显高于高LOX活性等位变异品种。

I.ipoxygenase （LOX） activity in wheat grain is significantly associated with the flour color and its end-use products, investigation of genetic polymorphism of LOX activity genes will provide im- portant information for further improvement of wheat quality in Shaanxi province. In this study, mo- lecular markersXwmc312 located on chromosome 1AL, LOXI6 and LOX18 at TaLOX-B1 located on chromosome 4BS, were used to detect 173 wheat cultivars and advanced lines in Shaanxi province, and the genetic polymorphism of the LOX activity genes was analyzed. At QLpx. caas. 1AL locus, three alleles Xwmc312 2zz , Xwmc312_235 andXwmc312 2.tz were found in Shaanxi wheat cultivars and advanced lines by the marker Xwmc312 . The frequencies of alleles Xwmc312 227 , Xwmc312.2s5 and Xwmc312-247 in the 173 materials were 31.21% （54 accessions）, 17. 920//00 （31 accessions）and 50.87% （88 acces- sions）, respectively. At TaLOX-B1 locus, two kinds of allelic variations TaLOX-I31a and TaLOX-Blb were distinguished by the functional markersLOX16 andLOX18 . In the tested materials, 39 of them （22.54%） belonged to TaLOX-BIa allele, whereas 134 of them （77.46%） belonged to TaL（）X-Blb allele. The frequencies of allelic combinations of Xwmc312247/TaLOX-Blb , Xwmc3122eT/TaLOX- B1 b , XwmcS12 2s~ /TaLOX 131b , XwmcSl2 227/TaLOX-Bla , Xwmc312 247/TaLOX-]31a and Xwmc312.235/TaLOX-Bla in Shaanxi wheat were 41.0%, 19.6%, 16.8%, 11.6%, 9.8% and 1.2%, respectively. The frequencies of six allelic combinations at the two loci were different in Shaanxi wheat, which were also different in distinct wheat regions of Shaanxi. The frequencies of allelic varia- tions of lower LOX activity in $haanxi wheat were significantly higher than that of the higher ones.