8个油橄榄品种扦插苗苗期耐寒性评价

Evaluation of Cold Tolerance of Eight Olive Varieties in Cuttage Seedlings

[目的]为探明油橄榄扦插苗苗期抗寒性评价方法。[方法]以中国北亚热带西秦岭南坡白龙江河谷地引种栽植的8个油橄榄品种2年生扦插苗为研究对象,人工模拟冷胁迫(16、12、8、4、0、-4℃),对其渗透调节物质含量,保护酶活性,光合和叶绿素荧光参数等指标进行分析。[结果]随着冷胁迫加剧,8个供试油橄榄品种幼苗叶片相对电导率(REC)、脯氨酸(Pro)、可溶性糖(SS)、可溶性蛋白(SP)含量呈上升趋势,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性在0℃前呈上升趋势,降至冰点后又开始逐渐降低;温度下降的过程中,各品种叶片叶绿素含量(Chl)、净光合速率(P_(n))、蒸腾速率(T_(r))、最大光化学效率(F_(v)/F_(m))、实际光化学效率(Φ_(PSⅡ))均呈现下降趋势,气孔导度(G_(s))在4℃前呈下降趋势。应用半致死温度(LT50),渗透调节物质、保护酶活性参数隶属函数,光合和叶绿素荧光参数隶属函数3种评价体系进行了相关分析,8个油橄榄品种扦插苗半致死温度介于-16.359~-9.715℃之间。[结论]通过渗透调节物质、保护酶活性参数隶属函数法所得出的耐寒性综合排序与应用电导法配合Logist-ic方程求出半致死温度的排序基本一致,并且符合试验地区油橄榄苗期越冬表现,可以作为油橄榄苗期耐寒性评价方法。

[Objective]To investigate the evaluation method of cold resistance of olive cuttings.[Methods]Eight two-year cuttage seedlings of olive varieties were introduced and planted in the valley of Bailong River on the southern slope of West Qinling Mountains in North subtropical China.Cold stress(16,12,8,4,0,-4℃)was simulated to measure the contents of osmotic regulation substances,protective en-zyme activities,photosynthesis and chlorophyll fluorescence parameters.[Results]With the increase of cold stress,the contents of relative electrical conductivity(REC),proline(Pro),soluble sugar(SS)and sol-uble protein(SP)in the leaves of 8 tested olive varieties showed an increasing trend,and the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)increased before 0℃and then began to gradually decreased after freezing point;During the process of temperature decrease,leaf chlorophyll content(Chl),net photosynthetic rate(P_(n)),stomatal conductance(G_(s)),intercellular CO2 con-centration(Ci),transpiration rate(T_(r)),maximum photochemical efficiency(F_(v)/F_(m))and actual photochemic-al efficiency(Φ_(PSⅡ))of all varieties showed a decreasing trend,stomatal conductance(G_(s))showed a de-creasing trend before-4℃.Correlation analysis was conducted using three evaluation systems:semi-leth-al temperature(LT50),membership functions of osmotic regulatory substances and protective enzymes,and membership functions of photosynthesis and chlorophyll fluorescence.The results showed that the semi-lethal temperature of eight olive varieties ranged from-16.359℃to-9.715℃.[Conclusion]The comprehensive ranking of cold resistance obtained by the method of subordinate function of the activity parameters of osmotic regulatory substances and protective enzymes is basically consistent with the rank-ing of semi-lethal temperature obtained by the method of conductivity and Logistic equation,and is consist-ent with the overwintering performance of olive in the test area.It can be used as an evaluation method for cold resistance of olive at seedling stage.