盐胁迫对小麦苗期荧光特性的影响及综合评价

为探究4份小麦苗期耐盐能力,筛选优异的高抗性种质资源,采用水培法,设置NaCl处理浓度为0、100、200 mmol/L,研究不同盐浓度对小麦幼苗生长发育、光合特性、叶绿素荧光特性、丙二醛含量和脯氨酸含量的影响,并通过主成分分析法和隶属函数法对4份小麦幼苗进行耐盐性综合评价。结果表明,随着盐浓度增加,各小麦品种叶鲜重、根鲜重、总根长、总根表面积、总根体积、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、光系统II最大光化学效率(Fv/Fm)、光系统II实际光化学效率(ΦPSII)和光化学猝灭(qP)与对照相比均有不同程度的下降,根平均直径、胞间CO₂浓度(Ci)、丙二醛含量(MDA)、非光化学猝灭(NPQ)和脯氨酸含量均有不同程度的上升。4份小麦盐胁迫下耐盐性由强到弱为‘冀麦32’>‘德抗961’>‘泰农18’>‘师栾02-1’。根据耐盐综合评价值筛选出‘冀麦32’和‘德抗961’具有较高的耐盐能力。

Effects of Salt Stress on Fluorescence Characteristics of Wheat Seedlings and Comprehensive Evaluation

To explore the salt tolerance of four wheat materials (‘Jimai 32’, ‘Tainong 18’, ‘Dekang 961’, ‘Shiluan 02-1’) at the seedling stage and screen out excellent germplasm resources with high stress resistance, water culture experiment was used in this research, NaCl stress concentrations were set as 0, 100, and 200 mmol/L, and the growth characteristics, photosynthetic characteristics, chlorophyll fluorescence parameters, malondialdehyde (MDA) content, and proline content were measured. The four wheat materials were evaluated by principal component analysis and membership function analysis for salt tolerance. The results showed that with the increase of salt concentration, leaf fresh weight, root fresh weight, total root length, total root surface area, total root volume, net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), photosystem Ⅱ maximum photosynthetic efficiency (Fv/Fm), photosystem Ⅱ actual photosynthesis efficiency (ΦPSⅡ) and photochemical quenching (qP) of each variety decreased in varying degrees compared with those of the control, while root average diameter, intercellular CO₂ concentration (Ci), malondialdehyde (MDA) concentration, non-photochemical quenching (NPQ) and proline content increased in varying degrees. The salt tolerance of the 4 varieties from strong to weak was ‘Jimai 32’> ‘Dekang 961’>‘Tainong 18’>‘Shiluan 02-1’. According to the multi-trait index of salt tolerance, ‘Jimai 32’ and ‘Dekang 961’ were screened to have high salt tolerance.