SH40中间砧苹果苗木休眠期假植失水原因分析及防护措施

Reason Analysis and Protective Measures of Temporary Planting SH40Interstock Apple Seedling Water Loss During the Period of Dormancy

SH40是目前我国华北地区主要应用的苹果矮化砧木。生产中冬季假植的SH40中间砧苹果苗木春季土壤解冻后往往出现中间砧段率先失水褶皱、随后整株失水现象,对生产极为不利。该研究以一年生冬季休眠期红富士/SH40/八棱海棠为试材,探究SH40中间砧苹果苗木休眠期假植中间砧段率先失水原因。结果表明:SH40中间砧苗木休眠期假植中间砧段率先失水与中间砧自身的品种特性关系不大;根系蒸腾是导致中间砧段率先失水褶皱的主要原因,当根系缺水,蒸腾量较大时,导管内部形成水势差,迫使中间砧水分逆向运移至根部。根系越庞大,中间砧段失水速率越快,失水褶皱情况越严重。失水率达20%是中间砧及接穗能够复水成活的阈值,超出阈值苗木即不能成活。

Currently,SH40 is the major application of apple dwarfing rootstocks in North China.During the production,SH40 interstocks segment apple seedling temporary planted would have the phenomena that loss water and occurs wrinkles at interstocks segment first and then even expand to the whole plant after the spring thaw soil,which is prejudicial to the production extremely.In this study,annual winter hibernation Fuji/SH40/Robusta was used as material and the reasons that the temporary planting SH40 interstocks apple seedling loss water in interstocks first during dormancy were studied.The results showed that,the reason that temporary planting SH40 interstocks seedling loss water at interstocks first during the dormancy period had not much relations to its varietal characteristics;the transpiration of roots system was a major reason that cause the interstocks segment loss water and occurs wrinkles first,and when the root lack water as well as the transpiration was large,there was a water potential difference in the conduit,which forced the migration in interstocks move to the roots reversely.Meanwhile,the larger root system was,the faster water loss rate was and the dehydration wrinkle was much more serious as well;the threshold that the interstocks and scion could rehydration successful was 20%of water loss rate,and the seedling cannot survive beyond the threshold.