为了探索作物萌发期耐盐性评价的无损检测方法,采用100 mmol/L的 NaCl溶液形成盐胁迫,研究了NaCl胁迫下2个玉米品种万瑞168号和郑单958号种子萌发过程中超弱光子辐射的变化规律。结果发现,在正常萌发过程中,2个玉米品种的种子自发光子辐射强度与鲜质量都呈现逐渐增长的趋势,相关系数r分别为0.962 51和0.982 27；在NaCl胁迫下,2个玉米品种的自发光子辐射强度与种子鲜质量的变化也呈现正相关,相关系数r分别为0.983 57和0.991 06, NaCl胁迫对萌发过程中2个玉米品种自发光子辐射和种子鲜质量的升高都有抑制作用。研究还发现,2个玉米品种在LED诱导下的延迟光子辐射也随着萌发进程逐渐增长,NaCl胁迫对2个玉米品种LED诱导下的延迟光子辐射的增长有不同的抑制作用。采用NaCl胁迫下萌发种子自发光子辐射的相对抑制率和延迟光子辐射的相对抑制率评价2个玉米品种萌发期耐盐性的强弱,评价结果与采用NaCl胁迫下种子萌发耐盐指数和储藏物质转运率的评价结果是相同的,表明根据NaCl胁迫下萌发种子自发光子辐射或者延迟光子辐射相对抑制率的大小可以无损伤的诊断与评价玉米萌发期耐盐性的强弱。

The diagnosis and evaluation of salt tolerance about crop during germination is the basic research of modern agriculture, and it has very important significance to ensure global food security.Currently, there are many reports on evaluation of salt tolerance during crop germination, and mostly based on morphological index such as the germination rate, germination energy, germ length, root length and seed fresh quality.These traditional evaluation methods have many defects such as a lot of work, very complex calculations, long measurement period, more amount of seeds to use, and not suitable for rare species.Ultraweak photon emission, including spontaneous photon emission and delayed photon emission induced by external light, is a kind of life information in the form of living cells.According to the changes of ultraweak photon emission, the noninvasive detection about the changes of metabolism and functional state of living cell can be achieved and may be applied to evaluate crops salt tolerance.In order to explore the noninvasive detection and evaluation method about the salt tolerance of corn during germination based on the ultraweak photon emission from germinating crop seed, NaCl with 100 mmol/L was used to form the salt stress, and this paper studied the differences of two corn varieties Wanrui No.168 and Zhengdan No.958 in salt tolerance during germination period based on the conventional seed germination salt tolerance index.At the same time, we also studied the differences of the spontaneous photon emission and delayed photon emission induced by blue LED about corn varieties Wanrui No.168 and Zhengdan No.958 during germination under the 100 mmol/L NaCl stress.The results showed that the seed fresh quality, spontaneous photon emission intensity and delayed photon emission integral intensity of two corns varieties Wanrui No.168 and Zhengdan No.958 gradually increased in the normal germination process, there was positive correlation between the changes of seed fresh quality and spontaneous photon emission(the correlation coefficient was 0.982 27 and 0.962 51 respectively).Under the 100 mmol/L NaCl stress, there was also a positive correlation between the seed fresh quality and spontaneous photon emission of two varieties of corn (the correlation coefficient was 0.983 57 and 0.991 06, respectively).The study also found that the NaCl stress inhibited the increase of seed fresh quality and spontaneous photon emission of the two corn varieties in different degrees, inhibitory effect of the NaCl stress on Zhengdan No.958 was greater than Wanrui No.168.According to the relative inhibition rate of NaCl stress on the spontaneous photon emission and delayed photon emission during germination could distinguish and evaluate the strength of salt tolerance about corn varieties Wanrui No.168 and Zhengdan No.958 during germination.Compared the evaluation result based on the relative inhibition rate on spontaneous photon emission and delayed photon emission from germinating seeds under the NaCl stress with the conventional seed germination salt tolerance index and storage material transport rate, the evaluation results were the same, and it showed that the evaluation methods based on the relative inhibition rate of spontaneous photon emission and delayed photon emission under the NaCl stress were reliable.The relative inhibition rate of spontaneous photon emission and delayed photon emission respectively reflected the impact of NaCl stress on cell metabolism and cell damage.Since the evaluation method about salt tolerance based on the spontaneous photon emission and delayed photon emission from germinating seeds cells has many advantages, such as sensitive, rapid, non destructive and so on, this method can reflect the response of cellular metabolism, adaptation and harm process under NaCl stress, and it is expected to become a kind of practical, wide applicability and reliable new method of evaluation salt tolerance on germinating crops seeds.

O482.31；Q632

国家自然科学基金(31471412,51277151)；陕西省教育厅科学研究计划专项(15JK1515)；西安理工大学科技创新计划项目(2013CX019)