铝胁迫对3种油茶初生根生理特性的影响

为耐铝基因筛选和油茶耐铝品种的选育提供参考,以广宁红花油茶、高州油茶和普通油茶为材料,采用水培法,研究在不同浓度、不同时间铝胁迫条件下初生根的生理变化。结果表明:铝胁迫24h后,3种油茶初生根生长受到抑制,广宁红花油茶、高州油茶和普通油茶在铝浓度为4mmol/L时的初生根相对伸长率分别为71.94%、54.57%和47.25%,初生根活力分别为89.05mgTTF/(g·h)、120.06mgTTF/(g·h)和87.05mgTTF/(g·h)。3种油茶初生根质膜透性随铝浓度升高和处理时间延长增大,胁迫结束时相对电导率达到峰值,广宁红花油茶、高州油茶和普通油茶在铝浓度为4mmol/L时,其相对电导率分别为65.80%、73.26%和75.28%。处理周期内,3种油茶SOD活性呈下降趋势,POD、CAT活性先升高后降低。胁迫结束时广宁红花油茶、高州油茶和普通油茶在铝浓度为4 mmol/L时的初生根MDA含量分别为11.72nmol/g、35.56nmol/g和21.46nmol/g,游离脯氨酸含量分别为610.97μg/g、649.63μg/g和687.75μg/g。油茶可通过一系列生理变化耐受铝胁迫伤害,不同油茶耐铝性存在差异,通过对铝胁迫条件下油茶初生根的各项生理指标比较分析得出,3中油茶中广宁红花油茶耐铝性最好,高州油茶次之,普通油茶最差。

Effect of Aluminum Stress on Physiological Characteristics of Primary Roots of Three Oil Tea Species

The physiological change of primary roots of Camellia semiserrata,Camellia gauchowensis and Camellia oleifera was analyzed by water culture method under Al stress with different concentration and treatment days to provide a reference for gene screening of Al tolerance and breeding of oil tea species with Al tolerance.Results:The primary root growth of three oil tea species is inhibited after 1 d Al stress.The relative elongation and activity of primary roots of C.semiserrata,C.gauchowensis and C.oleifera are 71.94％ and 89.05 mgTTF/(g · h),54.57％ and 120.06 mgTTF/(g · h),47.25％ and 87.05 mgTTF/(g · h)respectively when Al concentration is 4 mmol/L.The membrane permeability of primary roots of three oil tea species increases with increase of Al concentration and treatment hours and their relative conductance reaches the peak value when Al stress ends.The relative conductance of C.semiserrata,C.gauchowensis and C.oleifera is 65.80％,73.26％ and 75.28％ respectively when Al concentration is 4 mmol/L.The SOD activity of three oil tea species shows a declining trend but their POD and CAT activity presents a first rising and then declining trend under Al stress.The MDA and free proline content in primary roots of C.semiserrata,C.gauchowensis and C.oleifera is 11.72 nmol/g and 610.97 μg/g,35.56 nmol/g and 649.63 μg/g,21.46 nmol/g and 687.75 μg/g respectively when Al concentration is 4 mmol/L.The oil tea can resist Al stress by a series of physiological change but there is a difference in Al tolerance among different oil tea species.The Al tolerance of C.semiserrata is the best,followed by C.gauchowensis and C.olei f era.