晾晒对拉萨河谷5种乡土树种叶片脯氨酸和丙二醛含量的影响

Effects of Air-drying on Contents of Proline and Malondiadehyde in Leaves of Five Kinds of Native Tree Species in Valley of Lhasa River

为提高造林成活率,促进苗木生长,以拉萨河谷地区5种主要乡土造林树种(藏川杨、银白杨、细叶红柳、左旋柳和江孜沙棘)为研究对象,选取2—3年生的苗木进行晾根处理(晾晒时间为0h、2h、4h、6h及8h),晾晒后移栽,测定分析移栽成活苗木叶片脯氨酸(Pro)和丙二醛(MDA)含量的变化。结果表明:5个树种苗木叶片的脯氨酸和丙二醛含量均随晾晒时间的延长而增加,但变化幅度和进程不同。其中,藏川杨晾晒4h的增幅达最大,脯氨酸和丙二醛含量分别增加85.18%和43.10%;银白杨、细叶红柳和左旋柳晾晒6h后增幅均达最大,分别增加53.74%和67.57%,68.5%和297.04%,205.18%和43.62%;江孜沙棘晾晒8h后增幅达最大,分别增加70.93%和39.38%。5种树种裸根晾晒的极限时间分别为藏川杨4h,银白杨、细叶红柳和左旋柳6h,江孜沙棘8h,一定程度上反映出各树种的抗旱性。

To enhance the planting survival rate and promote seedling growth,taking five kinds of native tree species(Populus szechuanica var.tibetica,Populus alba var.alba,Salix microsiachya,Salix paraplesia var.subintegra and Hippophae gyantsensis)as the object,the effects of air-drying on contents of Proline and MDA in leaves were investigated by using bare root air-drying method,with the air-drying time of 0h,2h,4h,6h and 8h.Results:Contents of Pro and MDA increased with air-drying time,but the change range and process were different.P.szechuanica var.tibetica drying 4h was of the highest improvement,the contents of Proline and MDA increased by 85.18% and 43.10% respectively.P.alba var.alba,S.microsiachyaand S.paraplesia var.subintegra drying 6h reached the maximum growth of 53.74% and 67.57%,68.5% and 297.04%,205.18% and 43.62% respectively;H.gyantsensis drying 8h reached the maximum growth of 70.93% and 39.38%.The limit air-drying time of P.szechuanica var.tibetica was 4 h,P.alba var.alba,S.microsiachya,S.paraplesia var.subintegra was 6 h,H.gyantsensis was 8h,reflecting the drought resistance of each tree species to some extent.