烟草抗PVY的EMS突变体pvyr1筛选与抗性遗传初步分析

Identification and Genetic Analysis of Tobacco PVY-resistant EMS Mutant pvyr1

为了从烟草EMS突变体库中筛选抗马铃薯Y病毒(Potato virus Y,PVY)突变体,采用苗期人工接种初筛M2抗病单株,对M3、M4和M5株系连续接种鉴定PVY抗性。采用e IF4E1基因特异分子标记检测和c DNA全长测序,分析突变体PVY抗性是否与e IF4E1突变有关。配制F1群体初步分析抗性遗传特性。苗期人工接种从1800份M2种子中筛选到1份抗PVY的烤烟突变体。冬季无加温措施塑料大棚内苗期人工接种PVY坏死株系MN分离物,接种后35 d未诱变对照品种发病率为100%,E9119-1Z/M3株系的发病率为56.3%,无症状单株ELISA检测PVY均为阴性,表明E9119-1Z/M3株系对PVY中抗。E9119-1Z的M4株系和M5株系在光照培养室内苗期人工接种对PVY坏死株系MN分离物和ZT-5分离物表现为中抗。E9119-1Z-R14-2/M5株系为抗性稳定的突变体,命名为pvyr1。pvyr1采用e IF4E1基因特异分子标记检测为阳性,c DNA测序表明e IF4E1基因无突变。pvyr1与未诱变对照品种(感PVY)、va位点抗PVY品种NC55的杂交F1代抗性鉴定结果初步表明,pvyr1突变体对PVY的抗性符合孟德尔隐性遗传,且与NC55的va位点不等位。表明pvyr1为一个与e IF4E1基因突变不同的抗PVY新资源。

In order to screen for Potato virus Y(PVY)resistant mutant of tobacco among EMS mutant library,seedling inoculationwas used to screen for M2PVY-resistant plants,and continuous inoculation was conducted to identify M3,and M4and M5lines withresistance to PVY.The eIF4E1molecular marker test and full length cDNA sequencing were applied to analyze whether the PVYresistantmutations were associated with the eIF4E1mutation or not.F1populations were used for preliminary analysis of the geneticcharacteristics of the resistance.After artificial inoculation of1800M2lines at the seedling stage,a flue-cured tobacco mutant resistantto PVY necrotic strains was obtained.Seedlings were inoculated with PVY MN isolates and PVY ZT-5isolates.After35days postinoculated(dpi),the disease incidence of E9119-1Z M3line was56.3%while that of the WT control was100%.The symptomless M3plantlets were PVY negative when tested by ELISA.These primary results indicated that the E9119-1Z/M3line had medium resistanceto PVY.In the green house inoculation test the M4and M5lines descendent of E9119-1Z showed stable medium resistance to PVYnecrotic strains MN isolate and ZT-5isolate.The E9119-1Z-R14/M5was named pvyr1.Analysis of pvyr1hybrid F1with WT controland with the va locus PVY-resistant NC55line showed that the PVY resistance of pvyr1was in accord with Mendelian model ofrecessive gene and is not allelic to the NC55va locus.The eIF4E1gene specific molecular markers tests and cDNA sequencing resultsindicated that the pvyr1mutation is not related to the eIF4E1mutation.Mutant pvyr1can be used as a new PVY-resistant tobaccogermplasm.