干旱脅迫下水楊酸浸種對云南藍果樹幼苗生理響應的影響1)

張珊珊 康洪梅 楊文忠

(云南珍稀瀕特森林植物保護和繁育國家林業局重點實驗室(云南省林業科學院)，昆明，650201)

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干旱脅迫下水楊酸浸種對云南藍果樹幼苗生理響應的影響1)

張珊珊 康洪梅 楊文忠

(云南珍稀瀕特森林植物保護和繁育國家林業局重點實驗室(云南省林業科學院)，昆明，650201)

利用不同質量濃度(0、0.25、0.50、0.75、1.00 g·L-1)的水楊酸(SA)對云南藍果樹種子進行浸種處理和利用不同質量分數(0、5%、10%、15%)的PEG-6000溶液模擬不同強度的干旱脅迫(模擬的水勢分別為0、-0.1、-0.2、-0.4 MPa)，研究干旱脅迫下水楊酸浸種處理對云南藍果樹早期幼苗葉片生理指標的影響。結果表明：未經SA浸種處理時，隨著PEG-6000質量分數的增加，云南藍果樹早期幼苗葉片的超氧化物歧化酶(SOD)、過氧化物酶(POD)、過氧化氫酶(CAT)活性，脯氨酸(Pro)、可溶性糖質量分數顯著降低，而丙二醛(MDA)質量摩爾濃度顯著升高。隨著SA質量濃度的升高，SOD、POD、CAT活性，Pro、可溶性糖質量分數顯著升高，而MDA質量摩爾濃度顯著降低，意味著水楊酸對云南藍果樹種子的預處理一定程度上增強了其早期幼苗的抗旱性。因此，水楊酸浸種可減輕干旱脅迫對云南藍果樹早期幼苗的傷害。而且，云南藍果樹早期幼苗在水楊酸質量濃度高于0.75 g·L-1、水勢低于-0.1 MPa時，防御作用較強。建議育苗前對云南藍果樹種子進行SA預處理，最適質量濃度為0.75 g·L-1。

水楊酸；聚乙二醇-6000；云南藍果樹幼苗；生理指標；抗旱性

In order to understand the effects of salicylic acid pretreatment on physiological characteristics ofNyssayunnanensisseedlings under drought stress,N.yunnanensisseeds were soaked with different concentrations of salicylic acid (SA) (0, 0.25, 0.50, 0.75, 1.00 g·L-1) and treated with different concentrations of PEG-6000 solutions (0, 5%, 10%, 15%, and the simulated water potential were 0, -0.1, -0.2, and -0.4 MPa, respectively). The activities of POD, SOD and CAT as well as the contents of proline and soluble sugar inN.yunnanensisseedlings were significantly decreased but MDA content was significantly increased with the increase of PEG-6000 concentration without SA pretreatment. However, POD, SOD and CAT activities as well as proline and soluble sugar contents inN.yunnanensisseedlings were significantly increased but MDA content was significantly decreased with SA pretreatment. Their changes were positively improved with the increase of SA concentration at all levels of drought stresses simulated. The drought resistance ofN.yunnanensisseedlings might be strengthened by seed soaking with SA. Therefore, SA could relieve the damages toN.yunnanensisseedlings, which were caused by drought stress.N.yunnanensisseedlings showed stronger defensive function when SA concentration was higher than 0.75 g·L-1and PEG-6000 concentrations was lower than 5%. In conclusion, it is suggested thatN.yunnanensisseeds should be pretreated with SA at the optimum concentration of 0.75 g·L-1.

干旱脅迫下，植物體內的抗氧化酶系統、滲透調節物質、內源激素和蛋白質合成等生理生化指標的變化與作物的抗旱性存在一定的關系[1-6]?！?br>