高硼处理增强巨尾桉苗木对零上低温的适应

The High Boron Treament Enhaces Adaptation of Eucalyptus grandis×E.urophylla Seedlings on Low Temperatures above Zero

以木本植物巨尾桉为材料 ,研究在 0℃以上低温 ,高硼处理对巨尾桉苗木生长以及苗木叶切片浸出液的相对电导率 ;超氧阴离子 (O-.2 )产生速率 ;丙二醛 (MDA)含量 ;超氧化物歧化酶 (SOD)、过氧化物酶 (POD)、过氧化氢酶 (CAT)活性 ;苗木茎尖、根尖和叶片IAA含量的影响。实验方案是在经过有多种硼浓度和温度的预备试验的基础上选出有代表性的两种硼浓度和 6种温度进行进一步的研究。培养液均调至pH 6 8,每天 30 μmolm-2 s-1 光照 1 2h。结果表明 :在 0～8℃ ,高硼处理 (8 0 0mg L)的苗木地下部干重是对照处理 (2 86mg L)的7 1 4～ 2 81倍 ,地上部干重是对照处理的 4 80～ 2 1 4倍 ,总生物量是对照处理的 5 2 1～ 2 56倍 ;对照处理的相对电导率是高硼处理的 1 80～ 2 68倍 ,O-.2 产生速率是高硼处理的 2 0 1～2 84倍 ,MDA含量是高硼处理的 1 64～ 1 95倍 ;高硼处理的SOD活性是对照处理的 2 2 1～2 30倍 ,POD活性是对照处理的 1 47～ 1 58倍 ,CAT活性是对照处理的 2 0 8～ 2 0 4倍 ;对照处理茎尖的IAA含量是高硼处理的 1 67～ 1 63倍 ,根尖IAA含量是高硼处理的 1 42～ 1 46倍 ,高硼处理叶片的IAA含量是对照处理的 2 2 5～2 0 0倍。

Eucalyptus grandis×E.urophylla seedlings were used as materials,and the effects with high boron treament on low temperatures above zero on seedlings growth and the relative electric conductivity of the solution soaked out of leaf segments and O^(-.)_2 productive rate, malondialdehyde(MDA) contents, activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) of leaves and IAA contents of stems point,roots point and leaves were studied in this paper.The test scheme based on a series test in advance which included different temperatures and boron concentrations and 2 boron concentrations and 6 temperatures as terms of the test scheme were decided from them.The seedlings were cultured in pH 6.8 culture solution and put in condition of 30μmolm^(-2)s^(-1) 12h a day.The results showed that,in 0～8℃,roots dry weights of seedlings treated with high boron were 7.14-2.81 times as high as that of the control ones, stems dry weights of seedlings treated with high boron were 4.80-2.14 times and the total biomass of seedlings treated with high boron were 5.21-2.56 times.The relative electric conductivity of the solution soaked out of leaf segments treated with control was 1.80-2.68 times,O^(-.)_2 productive rate of leaves treated with control was 2.01-2.84 times and MDA contents of leaves treated with control was 1.64-1.95 times as high as that of the high boron ones.The SOD activities of leaves treated with high boron were 2.21-2.30 times, POD activities of leaves treated with high boron were 1.47-1.58 times and CAT activities of leaves treated with high boron 2.08-2.04 times as high as that of the control ones.The IAA contents of roots point and that of stems points treated with control was 1.67-1.63 times and 1.42-1.46 times respectively as high as that of the high boron ones.But the IAA contents of leaves treated with high boron were 2.25-2.00 times as high as that of the control ones.