红豆草种质苗期耐寒性筛选及评价

Screening and Evaluation of Seedling Stage Cold Tolerance in Different Sainfoin Varieties

为筛选抗寒性优异的红豆草(Onobrychis viciaefolia)材料,以国内外22份红豆草为研究对象,探讨4℃下分别处理0、1、3和5 d后其幼苗形态和生理指标对低温的响应差异。结果表明,随低温处理时间延长,供试红豆草株高、叶面积、地上生物量、地下生物量、叶片相对含水量、叶绿素a、叶绿素b、类胡萝卜素、叶绿体色素和根系活力均呈下降趋势,可溶性糖呈增加趋势,脯氨酸、可溶性蛋白、过氧化物酶活性均呈先升后降趋势,丙二醛和过氧化氢酶活性呈先降后升趋势,超氧化物歧化酶活性呈先升后降再升趋势。回归分析表明,地下生物量、过氧化物酶、脯氨酸、可溶性蛋白和叶片相对含水量可作为红豆草苗期耐寒性评价首选指标。隶属函数和聚类分析综合评价表明,甘肃红豆草和材料9155耐寒能力强,蒙农红豆草和新航红豆草耐寒能力次之,材料13709耐寒性最差。研究结果为耐寒红豆草新品种选育提供了种质材料。

In this study,22 sainfoin(Onobrychis viciaefolia)varieties were selected to screen for excellent cold tolerance.Various morphological and physiological indices were measured for 0 d(CK),1 d,3 d and 5 d at 4℃.The results showed that as the duration of cold stress increased,the plant height,leaf area,aboveground biomass,underground biomass,leaf relative water content,chlorophyll a,chlorophyll b,carotenoids,chloroplast pigments,and root activity of the tested sainfoin decreased,while the soluble sugar content increased.The contents of proline and soluble protein,and peroxidase activity increased initially and then decreased,whereas the malonaldehyde content and catalase activity decreased initially and then increased.Superoxide dismutase activity exhibited a biphasic trend,characterized by an initial increase,subsequent decrease,and final increase.Based on the results of regression analysis,underground biomass,peroxidase,proline,soluble protein,and leaf relative water content were identified as the primary indicators for evaluating the low⁃temperature tolerance of sainfoin at the seedling stage.The comprehensive evaluation of membership function and cluster analysis showed that sainfoin‘Gansu’and‘9155’exhibited the highest level of cold resistance,followed by‘Mengnong’and‘Xinhang’,while‘13709’showed the lowest cold resistance.The obtained results of the present study provided high quality materials for the selecting and breeding of new variet⁃ies of cold⁃tolerant sainfoin.