5份燕麦材料苗期耐盐性综合评价

为明确不同燕麦材料苗期耐盐能力强弱和筛选出优异的燕麦种质,以前期试验筛选出的5份耐盐性较好的燕麦为材料,采用营养液沙培法,对3周龄幼苗进行0.9%NaCl连续处理7 d后,研究盐胁迫对供试燕麦幼苗生长特性、光合特性、叶绿素荧光参数、抗氧化酶活性、丙二醛含量和渗透调节物质含量等的影响,并通过主成分分析法和隶属函数法对5份燕麦苗期进行耐盐性综合评价。结果表明,盐胁迫下,供试材料各指标间差异显著(P<0.05)。青永久195相对白燕7号、青永久30、陇燕5号、陇燕4号有着较大的根表面积、根体积、较高的K⁺含量,较低的MDA含量,较高的P_n、qP、叶绿素含量以及POD活性;而青永久30的SOD、CAT活性大于其余材料;通过主成分分析筛选出无机渗透调节物质、膜脂过氧化性、抗氧化酶活性可作为燕麦苗期耐盐性评价的综合鉴定指标,根据耐盐综合评价值(D)得出材料耐盐性排序为青永久195>白燕7号>青永久30>陇燕5号>陇燕4号。

A multi-trait evaluation of salt tolerance of 5 oat germplasm lines at the seedling stage

In order to determine the salt tolerance of different oat breeding materials at the seedling stage and select elite oat germplasm lines, five screened salt-tolerant oat germplasm lines from a previous experiment (Baiyan No.7, Longyan No.4 and No.5, and Qingyongjiu 30 and 195), were studied in this research. In a sand culture experiment, 3-week old seedlings were treated with 0.9% NaCl solution for 7 days, and the growth characteristics, photosynthetic characteristics, chlorophyll fluorescence parameters, antioxidant enzyme activities, tissue malondialdehyde (MDA) concentration, and osmolyte content were measured. The salt tolerance of the five oat germplasm lines was evaluated by principal component analysis and membership function analysis of the seedling data. It was found that there were significant differences (P<0.05) between the tested germplasm lines for performance under salt stress. Qingyongjiu 195 had a larger root surface area and root volume, a higher K⁺ content, a lower MDA content, and higher net photosynthetic rate, electron transfer rate, photochemical quenching, chlorophyll content and peroxidase activity, than the other 4 tested varieties. Meanwhile, Qingyongjiu 30 had greater superoxide dismutase and catalase activities than other germplasm lines. Through principal component analysis, inorganic osmotic regulation substances, membrane lipid peroxidation and antioxidant enzyme activity were identified as traits which could be used in a multi-trait evaluation index for salt tolerance of oats at the seedling stage. According to the multi-trait index of salt tolerance (D), the salt tolerance of the germplasm lines ranked as follows: Qingyongjiu 195>Baiyan No.7>Qingyongjiu 30>Longyan No.5>Longyan No.4.