Studies On Cold Resistance And Its Physiological And Biochemical Basis In Micro-endosperm Maize At Germinating And Seeding Stage

Five micro-endosperm maize (ME for short) hybrid combinations were selected as materials in this experiment to study their cold resistance with Gaoyou115and Zhengtian68as control. A series of physiological and biochemical indexes (relative germination rate, relative germination energy, relative conductivity, MDA, Proline, soluble sugar, soluble protein, Chlorophyll content and SOD, POD activity) were measured at germinating and seeding stage. Their cold resistance was identified comprehensively using by the fuzzy administering function, providing theoretical reference for techniques of cold cultivation and cold breeding of micro-endosperm super-high oil maize. The main results were as follows:1. There were significant differences in cold resistance of every material at germinating and seeding stage.2. The cold resistance of the five micro-endosperm maize were different either at germinating stage or seeding stage. They were stronger or weaker compared with Gaoyou115, but stronger than Zhengtian68. The cold resistance of ME2was the strongest either at germinating stage or seeding stage. The cold resistance of ME3was strong at germinating stage but ordinary at seeding stage. The cold resistance of ME4and ME5were all weak at germinating and seeding stage.3. The correlation between most physiological and biochemical indexes at germinating stage was not significant or very significant, showed that the comprehensive evaluation combined with the determination results of several indexes should be more reasonable when identifying the cold resistance at germinating stage.4. It was appropriate to identify the cold resistance of micro-endosperm maize using by this five indexes (relative germination rate, relative germination energy, relative conductivity, Proline content, SOD activity) at germinating stage. It was appropriate to identify the cold resistance using by this five indexes (MDA, Proline, soluble sugar content, SOD and POD activity) at seeding stage.5. The comprehensive evaluation result according to the membership function value showed that it is possible that the material of strong cold resistance at germinating and seeding stage can be bred from micro-endosperm maize.