抗TMV的N导入片段在烤烟中的连锁累赘田间表型分析

Linkage Drag Field Phenotype Analysis of Flue-cured Tobacco with TMVResistant N Introgression Fragments

作物育种中的一个著名案例是烤烟中来源于心叶烟(Nicotiana glutinosa)的携带N基因的导入片段(N导入片段)。N导入片段赋予烤烟品种烟草花叶病毒(tobacco mosaic virus, TMV)抗性,同时带来田间落黄慢等连锁累赘。为分析烤烟N导入片段连锁累赘的田间表型,本研究以Coker176类型的N导入片段烤烟近等基因系为材料,测定成熟叶片的叶绿素含量和叶片厚度。结果表明,N导入片段带来烤烟采烤期中部叶绿素含量增加,上部叶叶绿素含量增加约25%,叶片厚度增加约8%。采烤期上部叶叶绿素含量高和叶片厚度增加,可能是现有携带N导入片段抗TMV烤烟品种田间落黄较慢、烘烤较难和产量产值降低的原因。田间测量采用手持叶绿素测定仪和手持厚度计,采烤期上部叶叶绿素含量和叶片厚度可作为定量评价烤烟N导入片段的连锁累赘指标。

A well-known crop breeding case is the import of N gene introgression fragments from Nicotiana glutinosa to flue-cured tobacco.The N introgression fragments give the flue-cured tobacco variety Tobacco mosaic virus(TMV)resistance,while bring the linkage drag of slow yellowing in field.In this study,to analysis linkage drag of flue-cured tobacco with N introgression fragments in filed.Coker176 type of N introgression fragments near isogenic line flue-cured tobacco was used to determine the content of mature leaf chlorophyll and leaf thickness.The results showed that the N introgression fragments increased the chlorophyll content of the middle leaves,the chlorophyll content of the upper leaves in harvested period by 25%,and increased of the leaves thickness about 8%.The higher content of chlorophyll and leaf thickness of the upper leaves during the harvested period may be the reason of the TMV resistant flue-cured tobacco yellowing slower,more difficult to cure and lower output.And field measurement can be carried out using a hand-held chlorophyll measuring instrument and a hand-held thickness meter.The upper leave chlorophyll content and leaf thickness in harvested period can be used as a quantitative evaluation of linkage burden index of N introgression segment in flue-cured tobacco.