4个杜梨半同胞家系苗期耐盐性分析

【目的】研究4个杜梨半同胞家系耐盐性差异,为沿海地区杜梨耐盐品种的筛选和推广提供参考。【方法】以滨海地区采集的4个杜梨半同胞家系实生苗为试材[编号为盐城(YC)、青岛20(QD20)、青岛14(QD14)和连云港(LYG)],采用室内盆栽方法,以不同浓度NaCl(质量分数梯度为0、0.2%、0.4%、0.6%、0.8%)进行盐胁迫处理,通过对其存活率、苗高、地径、生物量及根冠比、细胞膜透性、叶绿素含量和光合特性等生长和生理指标测定,分析4个杜梨半同胞家系耐受盐胁迫的能力,并运用因子分析和隶属函数法对4个家系的耐盐性进行综合评价。【结果】随着盐胁迫浓度升高,4个杜梨家系幼苗成活率均逐渐降低,其中YC成活率最高;根冠比呈先上升后下降的趋势,YC和QD14在0.6%盐处理下达到最大值,而QD20和LYG分别在0.2%和0.4%下达最大值;各家系的苗高、地径和总生物量均受到显著抑制,在0.2%盐处理处理下,YC降幅最小,同比对照分别降低了37.00%、18.69%和24.98%,而LYG的苗高增量和总生物量降幅最大,分别降低了95.42%和50.71%;4个杜梨家系叶片的净光合速率、气孔导度、蒸腾速率和叶绿素含量变化趋势一致,均随着胁迫浓度升高而降低,其中YC降幅最小,而LYG降幅最大;叶片细胞膜透性却逐渐升高,与对照相比,4个杜梨家系叶片膜透性在0.6%处理水平下均显著升高,其中LYG和QD14升幅较大,分别达到231.11%和238.97%,而YC和QD20的升幅较小,分别为67.77%和98.42%;4个杜梨家系叶片胞间二氧化碳浓度变化存在差异,随着盐处理水平升高,LYG和QD20呈先降低后升高的趋势,YC则一直降低,而QD14与YC相反。经因子分析和隶属函数分析,4个杜梨家系耐盐强弱依次为盐城>青岛14>青岛20>连云港。【结论】4个杜梨半同胞家系的耐盐性存在明显差异,盐城家系的综合耐盐能力最强,其次为青岛14和青岛20,连云港家系最弱。

Salt tolerance of four half-sib families of Pyrus betulaefolia Bunge from coastal areas

【Objective】This research investigated the differences of salt tolerance among four half-sib families of Pyrus betulaefolia Bunge in order to provide a reference for the selection and promotion of salt tolerant varieties in coastal areas.【Method】The seedlings of 4 half-sib families collected from coastal areas were used as test materials[No. YC, QD20, QD14 and LYG], which were treated with different concentrations of NaCl (0, 0.2%, 0.4%, 0.6%, 0.8%) through indoor soil culture and pot culture experiments. The growth and physiology indicators were measured to analyze the salt tolerance ability among four half-sib families of Pyrus betulaefolia Bunge such as the survival rate, biomass, root/shoot ratio, cell membrane permeability, chlorophyll content and photosynthetic characteristics. The salt tolerance of four families was comprehensively evaluated by a factor analysis and membership function method.【Result】With the increase of salt stress concentration, the survival rate of seedlings of four Pyrus betulaefolia Bunge families decreased gradually, of which YC was the highest. The root/shoot ratio increased first and then decreased. YC and QD14 reached the maximum value at 0.6% salt concentration, while QD20 and LYG reached the maximum value at 0.2% and 0.4% salt concentration respectively. Compared with the control, the seedling height, ground diameter and the total biomass of each family were significantly inhibited at 0.2% and YC decreased the least by 37.00%, 18.69% and 24.98%, respectively. The seedling height increment and the total biomass of LYG decreased the most by 95.42% and 50.71%, respectively. With the increase of stress concentration, the change trends of net photosynthetic rate, stomatal conductance, transpiration rate and chlorophyll content of four Pyrus betulaefolia Bunge families were the same and they all decreased, among which there indexes of YC decreased the least and those of LYG decreased the most. The membrane permeability of four families increased gradually and it decreased significantly at the level of 0.6%, among which the increases of LYG and QD14 were larger, reaching 231.11% and 238.97% respectively but the increase of YC and QD20 was smaller, reaching 67.77% and 98.42% respectively. The changes of intercellular carbon dioxide concentration of leaves of four families were different with the increase of salt treatment level. LYG and QD20 showed a trend from a decline to a rise and YC presented the downward trend all the time, while QD14 was opposite to YC. Through the factor analysis and membership function analysis, the salt tolerance of the four families was in order of Yancheng > Qingdao14 > Qingdao20 > Lianyungang.【Conclusion】There were significant differences in salt tolerance among four half-sib families of Pyrus betulaefolia. The comprehensive salt tolerance of Yancheng family was the strongest followed by Qingdao 14 and Qingdao 20 and the Lianyungang family was the weakest.