【作者】 刘亚丽；

【导师】 王庆成；

【作者基本信息】 东北林业大学 ， 森林培育， 2011， 博士

【摘要】 脂松(Pinus resinosa Ait.)是美国东北部地区最主要的造林树种之一,材质优良、用途广泛。2004年在我国东北东部山地地区引种,获得初步成功,但栽培过程中发现,部分微立地上脂松幼树越冬后出现针叶黄化甚至整株枯死,初步分析认为与土壤水分、变温和光氧化等因素有关。本文采用盆栽方法研究不同土壤水分(水淹处理、100%、80%、60%、40%、20%田间持水量,分别记为FL、FC、FC80、FC60、FC40和FC20)处理下苗木的生理响应,对不同土壤水分条件下脂松苗木的适应机制和耐受性进行评价；同时,对经过不同处理(秋季涝渍、秋季变温和冬季遮荫)的苗木进行自然越冬试验,通过生理指标的变化,结合越冬伤害和恢复情况,分析其发生越冬伤害的原因。主要研究结论如下：(1)不同土壤含水量处理对脂松苗木生长和生物量有显著影响(p<0.05),FC60处理下,苗高、地径、生物量均明显高于其它处理。低土壤含水量处理下苗木的生长和生物量均下降,根冠比显著增加(p<0.05),FC40和FC20处理下,苗木的生物量较FC60处理分别降低了17%和26%。高土壤含水量FC80、FC和FL处理,苗木生长和生物量也有所下降,根冠比显著降低(p<0.05),其中FL较FC60处理的生物量下降了41%。(2)不同土壤含水量处理对脂松苗木针叶的质膜稳定性有明显影响,对MDA的含量有显著影响(p<0.05)。FC60处理下,针叶中MDA含量和相对电导率均最低,FC40处理针叶MDA含量低于FC20处理,FC80、FC、FL处理MDA含量依次增大。FL处理针叶MDA含量升高明显,处理7 d,14 d和21 d时,MDA含量分别较FC60处理高出92.2%,46.1%和70.0%。(3)不同土壤含水量处理对脂松苗木针叶的抗氧化系统有明显的影响,其中对POD、CAT影响显著(p<0.05)。FC60处理CAT活性最高,POD活性较低。FC40处理针叶CAT活性>FC20处理,POD活性<FC20处理；FC80、FC及FL处理苗木针叶CAT活性依次降低,POD活性依次升高。土壤水分胁迫引起针叶CAT和POD的活性的规律性变化。(4)不同土壤含水量对脂松苗木针叶渗透调节物质含量有显著影响(p<0.05)。FC60处理下,苗木针叶脯氨酸和可溶性糖含量最低。FC20处理下针叶脯氨酸和可溶性糖含量高于FC40;FC80、FC和FL处理下的针叶脯氨酸和可溶性糖含量依次升高。其中FC20和FL两种处理下,两种物质的含量最高,处理21 d时,脯氨酸含量分别比FC60处理高出4.9倍和5.8倍,可溶性糖含量分别高出1.4倍和1.9倍。(5)不同土壤含水量对脂松苗木针叶的光合代谢有明显影响,对光合色素Chla、Chlb和叶绿素总量,光合参数Pn、Tr、Gs及荧光参数Fo、Fm、Fv、Fv/Fm、ΦPSⅡ均有显著影响(p<0.05)。FC60处理时,苗木针叶叶绿素总量、Pn、Fv/Fm和ΦPSII均最高；FC40处理苗木叶绿素总量、Pn、Chla、Chlb、Car均高于FC20处理,FC80、FC及FL处理上述指标依次下降。其中FC20和FL处理的叶绿素总量较FC60处理分别降低了44.7%和49.2%,干旱和水湿处理均对苗木针叶产生较强的光抑制。(6)解除胁迫后,FC40和FC20处理及FC80、FC及FL处理后苗木各项生理指标均有不同程度的恢复,其中FC80、FC和FC40处理恢复较快；而FC20和FL处理在胁迫解除2w时部分指标尚未完全恢复。(7)冬季遮荫处理可以提高脂松苗木抗寒性,减少越冬伤害和死亡率。在越冬前期的降温过程中,与对照相比遮荫处理的针叶质膜透性减少、MDA含量减少,抗氧化酶系统、脯氨酸及可溶性糖等渗透调节物质含量均发生了有利于增强抗寒能力的改变。发生越冬伤害苗木比对照降低4%,随着越冬后期气温的回升,遮荫处理苗木针叶的各项生理指标均有所恢复,越冬后死亡率较对照降低4%。(8)秋季涝渍处理或秋季变温处理均明显降低脂松苗木抗寒性,导致苗木越冬伤害和死亡。与对照相比,秋季涝渍处理或秋季变温处理的苗木在越冬前期针叶质膜透性增加、抗氧化酶系统、脯氨酸及可溶性糖等渗透调节物质含量均发生了不利于苗木抗寒性的变化。随着越冬后期气温的回升,两种处理苗木针叶的各项生理指标均有所恢复,但越冬伤害程度和死亡率均高于对照。3月份时,秋季涝渍处理和秋季变温处理苗木针叶变色率分别达到44%和100%,分别比对照高出30%和86%,5月份时苗木死亡率较对照高出4%和10%。综上所述,脂松遭受到干旱、涝渍和低温逆境时,表现出不同的适应性。脂松比较耐干旱而不耐涝渍,60%土壤含水量条件下苗木综合表现最佳,适宜在中等偏干旱土壤条件下栽培；脂松苗木具有较强的抗寒性,能够对各种低温逆境迅速做出反应；冬季遮荫有利于脂松苗木的安全越冬；秋季涝渍或秋季变温处理均导致脂松苗木的抗寒性下降,增加苗木的越冬伤害。更多还原

【Abstract】 Red pine (Pinus resinosa Ait.) is one of the major tree species for afforestation in the northeast areas of the United States of America with good material quality and wide usage. In 2004, preliminary success was achieved in the introduction of red pines in the eastern mountainous regions of Northeast China. It was found in the process of cultivation that etiolation of needles and even withering to death of the whole plant occurred in red pine saplings at parts of microsites after overwintering, which was thought to be linked with factors such as soil moisture, temperature fluctuation, photooxidation and so on by the preliminary analysis. The pot cultivation method was adopted to study physiological response of seedlings under different treatments of soil moisture(flooding treatment,100%,80%,60%,40% and 20% of field capacity were respectively marked by FC, FC80, FC60, FC40 and FC20) and to evaluate the adaptability mechanism and tolerance of red pine seedlings under different conditions of soil moisture. Meanwhile the experiment of natural overwintering was conducted on seedlings under different treatments (including autumn waterlogging, autumn temperature fluctuation and winter shading); by means of variation of physiological indicators, the cause of winter injury was analysed in combination of the situation of winter injury and recovery. The main research conclusions were as follows:(1)The different soil moisture treatments had significant influence on growth and biomass of red pine seedlings(p<0.05).Under the treatment of FC60, seedling height, caliper and biomass were all significantly higher than those under the other treatments. Under the low soil moisture treatments, growth and biomass of seedlings both decreased, and root shoot ratio increased significantly(p<0.05).Under the treatments of FC40 and FC20, biomass of seedlings dropped respectively by 17% and 26% over that under the treatment of FC60. Under the high soil moisture treatments of FC80, FC and FL, growth and biomass of seedlings decreased to some extent, and root shoot ratio decreased significantly(p<0.05). Thereinto, biomass under the treatment of FL dropped by 41% over that under the treatment of FC60.(2)The different soil moisture treatments had obvious influence on the plasma membrane stability of red pine seedling needlings, and had significant influence on the content of MDA(p<0.05). Under the treatment of FC60, the content of MDA and relative electrical conductivity in needlings were both the lowest. The content of MDA under the treatment of FC40 was lower than that under the treatment of FC20. The contents of MDA under the treatments of FC80, FC and FL increased successively. The content of MDA under the treatment of FL rose obviously, which was respectively 92.2%,46.1% and 70.0% higher than that under the treatment of FC60 on the 7th,14th and 21th day.(3)The different soil moisture treatments had obvious influence on the antioxidation system of red pine seedling needlings, thereinto, they had significant influence on POD and CAT(p<0.05). Under the treatment of FC60, the activity of CAT was the highest, while the activity of POD was lower. Under the treatment of FC40, the activity of CAT in needlings was higher than that under the treatment of FC20, and the activity of POD was lower than that under the treatment of FC20. Under the treatments of FC80, FC and FL, the activities of CAT in seedling needlings decreased successively and the activities of POD increased successively. Soil water stress caused regular variation of the activities of CAT and POD in needlings.(4)The different soil moisture treatments had significant influence on the contents of osmoregulation substances in red pine seedling needlings (p<0.05). Under the treatment of FC60, the contents of proline and soluble sugar in seedling needlings were the lowest. The contents of proline and soluble sugar in seedling needlings under the treatment of FC20 were higher than those under the treatment of FC40. The contents of proline and soluble sugar in seedling needlings under the treatments of FC80, FC and FL increased successively. Thereinto, the contents of proline and soluble sugar under the two treatments of FC20 and FL were the highest. On the 21st day of treatment, the content of proline was respectively 4.9 times and 5.8 times higher than that under the treatment of FC60, and the content of soluble sugar was respectively 1.4 times and 1.9 times higher than that under the treatment of FC60.(5)The different soil moisture treatments had obvious influence on the photosynthetic metabolism of red pine seedling needlings, and had significant influence on photosynthetic pigments(Chla, Chlb and total content of chlorophyll), photosynthetic parameters(Pn, Tr and Gs) and fluorescence parameters(Fo,Fm,Fv,Fv/Fm,ΦPSII) (p<0.05). Under the treatment of FC60, the total content of chlorophyll, Pn, Fv/Fm andΦPSII in seedling needlings were all the highest. The total content of chlorophyll, Pn, Chla, Chlb and Car under the treatment of FC40 were all higher than those under the treatment of FC20. Above-mentioned indicators for the treatments of FC80, FC and FL decreased successively. The total contents of chlorophyll under the treatments of FC20 and FL decreased respectively by 44.7% and 49.2% over that under the treatment of FC60. Drought and waterlogging treatment both posed stronger light restrain to seedling needlings.(6)After stress relief, there was recovery of different extents in all physiological indicators for the treatments of FC40 and FC20, and the treatments of FC80, FC and FL, among which the indicators for the treatments of FC80, FC and FC40 got recovered faster. However, some index value under the treatments of FC20 and FL at the second week after stress relief didn’t achieve full-recovery yet. (7)The winter shading treatment was able to improve cold resistance of red pine seedling and reduce winter injury and mortality rates. In the process of temperature drop of early overwintering, compared with the check, the permeability of plasma membrane of needlings under the shading treatment decreased; the content of MDA reduced; and variation which was favorable to improving cold resistance capacity occurred in both the antioxidant enzyme system and the contents of osmoregulation substances such as proline, soluble sugar and so on. Seedlings which suffered winter injury were 4% lower than those under check. With the rising again of air temperature of late overwintering, all physiological indicators for seedling needlings under the shading treatment got recovered to some extent, and the mortality rate decreased by 4% over that under check after overwintering.(8)The treatments of autumn waterlogging or temperature fluctuation both obviously reduced cold resistance of red pine seedlings, and caused winter injury and mortality of seedlings. Compared with the check, the permeability of plasma membrane of seedling needlings under the treatments of autumn waterlogging and temperature fluctuation increased; variation which was not favorable to cold resistance occurred in the permeability of plasma membrane, the antioxidant enzyme system and the contents of osmoregulation substances such as proline and soluble sugar of seedlings in the early overwintering. With the rising again of air temperature of late overwintering, all physiological indicators for seedling needlings under the two treatments got recovered to some extent, but the degrees of winter injury and mortality rates were both higher than those under check. In March, the discoloration rates of seedling needlings under the treatments of autumn waterlogging and temperature fluctuation reached 44% and 100% respectively,30% and 86% higher than those under check. In May, the mortality rates of seedlings were respectively 4% and 10% higher than those under check.In summary, red pines displayed different adaptability when they were subjected to adversity of drought, waterlogging and low temperature. Red pines resisted drought rather than waterlogging. The seedlings under the condition of 60% of field capacity presented the optimum comprehensive performance. Red pines were suitable to be cultivated under the condition of moderately inclined arid soil. Red pines had stronger cold resistance and were able to response quickly to low temperature adversity of various kinds. Winter shading was favorable to safe overwintering of red pine seedlings. Either autumn waterlogging or autumn temperature fluctuation would cause decrease of cold resistance of red pine seedlings so as to increase the degree of winter injury of seedlings.更多还原