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

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。

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

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 0 h, 2 h, 4 h, 6 h and 8 h.Results: Contents of Pro and MDA increased with air-drying time, but the change range and process were different.P.szechuanica var.tibetica drying 4 h was of the highest improvement, the contents of Proline and MDA increased by 85.18% and 43.10% respectively.P.alba var.alba, S.microsiachya and S.paraplesia var.subintegra drying 6 h reached the maximum growth of 53.74% and 67.57%, 68.5% and 297.04%, 205.18% and 43.62% respectively;H.gyantsensis drying 8 h 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 8 h, reflecting the drought resistance of each tree species to some extent.